Cleanup

[carla.git] / source / modules / dgl / src / nanovg / fontstash.h

//
// Copyright (c) 2009-2013 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty.  In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//

#ifndef FONS_H
#define FONS_H

#define FONS_INVALID -1

enum FONSflags {
        FONS_ZERO_TOPLEFT = 1,
        FONS_ZERO_BOTTOMLEFT = 2,
};

enum FONSalign {
        // Horizontal align
        FONS_ALIGN_LEFT         = 1<<0, // Default
        FONS_ALIGN_CENTER       = 1<<1,
        FONS_ALIGN_RIGHT        = 1<<2,
        // Vertical align
        FONS_ALIGN_TOP          = 1<<3,
        FONS_ALIGN_MIDDLE       = 1<<4,
        FONS_ALIGN_BOTTOM       = 1<<5,
        FONS_ALIGN_BASELINE     = 1<<6, // Default
};

enum FONSglyphBitmap {
        FONS_GLYPH_BITMAP_OPTIONAL = 1,
        FONS_GLYPH_BITMAP_REQUIRED = 2,
};

enum FONSerrorCode {
        // Font atlas is full.
        FONS_ATLAS_FULL = 1,
        // Scratch memory used to render glyphs is full, requested size reported in 'val', you may need to bump up FONS_SCRATCH_BUF_SIZE.
        FONS_SCRATCH_FULL = 2,
        // Calls to fonsPushState has created too large stack, if you need deep state stack bump up FONS_MAX_STATES.
        FONS_STATES_OVERFLOW = 3,
        // Trying to pop too many states fonsPopState().
        FONS_STATES_UNDERFLOW = 4,
};

struct FONSparams {
        int width, height;
        unsigned char flags;
        void* userPtr;
        int (*renderCreate)(void* uptr, int width, int height);
        int (*renderResize)(void* uptr, int width, int height);
        void (*renderUpdate)(void* uptr, int* rect, const unsigned char* data);
        void (*renderDraw)(void* uptr, const float* verts, const float* tcoords, const unsigned int* colors, int nverts);
        void (*renderDelete)(void* uptr);
};
typedef struct FONSparams FONSparams;

struct FONSquad
{
        float x0,y0,s0,t0;
        float x1,y1,s1,t1;
};
typedef struct FONSquad FONSquad;

struct FONStextIter {
        float x, y, nextx, nexty, scale, spacing;
        unsigned int codepoint;
        short isize, iblur;
        struct FONSfont* font;
        int prevGlyphIndex;
        const char* str;
        const char* next;
        const char* end;
        unsigned int utf8state;
        int bitmapOption;
};
typedef struct FONStextIter FONStextIter;

typedef struct FONScontext FONScontext;

// Constructor and destructor.
FONScontext* fonsCreateInternal(FONSparams* params);
void fonsDeleteInternal(FONScontext* s);

void fonsSetErrorCallback(FONScontext* s, void (*callback)(void* uptr, int error, int val), void* uptr);
// Returns current atlas size.
void fonsGetAtlasSize(FONScontext* s, int* width, int* height);
// Expands the atlas size.
int fonsExpandAtlas(FONScontext* s, int width, int height);
// Resets the whole stash.
int fonsResetAtlas(FONScontext* stash, int width, int height);

// Add fonts
int fonsAddFont(FONScontext* s, const char* name, const char* path, int fontIndex);
int fonsAddFontMem(FONScontext* s, const char* name, unsigned char* data, int ndata, int freeData, int fontIndex);
int fonsGetFontByName(FONScontext* s, const char* name);

// State handling
void fonsPushState(FONScontext* s);
void fonsPopState(FONScontext* s);
void fonsClearState(FONScontext* s);

// State setting
void fonsSetSize(FONScontext* s, float size);
void fonsSetColor(FONScontext* s, unsigned int color);
void fonsSetSpacing(FONScontext* s, float spacing);
void fonsSetBlur(FONScontext* s, float blur);
void fonsSetAlign(FONScontext* s, int align);
void fonsSetFont(FONScontext* s, int font);

// Draw text
float fonsDrawText(FONScontext* s, float x, float y, const char* string, const char* end);

// Measure text
float fonsTextBounds(FONScontext* s, float x, float y, const char* string, const char* end, float* bounds);
void fonsLineBounds(FONScontext* s, float y, float* miny, float* maxy);
void fonsVertMetrics(FONScontext* s, float* ascender, float* descender, float* lineh);

// Text iterator
int fonsTextIterInit(FONScontext* stash, FONStextIter* iter, float x, float y, const char* str, const char* end, int bitmapOption);
int fonsTextIterNext(FONScontext* stash, FONStextIter* iter, struct FONSquad* quad);

// Pull texture changes
const unsigned char* fonsGetTextureData(FONScontext* stash, int* width, int* height);
int fonsValidateTexture(FONScontext* s, int* dirty);

// Draws the stash texture for debugging
void fonsDrawDebug(FONScontext* s, float x, float y);

#endif // FONTSTASH_H


#ifdef FONTSTASH_IMPLEMENTATION

#define FONS_NOTUSED(v)  (void)sizeof(v)

#ifdef FONS_USE_FREETYPE

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_ADVANCES_H
#include <math.h>

struct FONSttFontImpl {
        FT_Face font;
};
typedef struct FONSttFontImpl FONSttFontImpl;

#else

#define STB_TRUETYPE_IMPLEMENTATION
static void* fons__tmpalloc(size_t size, void* up);
static void fons__tmpfree(void* ptr, void* up);
#define STBTT_malloc(x,u)    fons__tmpalloc(x,u)
#define STBTT_free(x,u)      fons__tmpfree(x,u)
#include "stb_truetype.h"

struct FONSttFontImpl {
        stbtt_fontinfo font;
};
typedef struct FONSttFontImpl FONSttFontImpl;

#endif

#ifndef FONS_SCRATCH_BUF_SIZE
#       define FONS_SCRATCH_BUF_SIZE 96000
#endif
#ifndef FONS_HASH_LUT_SIZE
#       define FONS_HASH_LUT_SIZE 256
#endif
#ifndef FONS_INIT_FONTS
#       define FONS_INIT_FONTS 4
#endif
#ifndef FONS_INIT_GLYPHS
#       define FONS_INIT_GLYPHS 256
#endif
#ifndef FONS_INIT_ATLAS_NODES
#       define FONS_INIT_ATLAS_NODES 256
#endif
#ifndef FONS_VERTEX_COUNT
#       define FONS_VERTEX_COUNT 1024
#endif
#ifndef FONS_MAX_STATES
#       define FONS_MAX_STATES 20
#endif
#ifndef FONS_MAX_FALLBACKS
#       define FONS_MAX_FALLBACKS 20
#endif

static unsigned int fons__hashint(unsigned int a)
{
        a += ~(a<<15);
        a ^=  (a>>10);
        a +=  (a<<3);
        a ^=  (a>>6);
        a += ~(a<<11);
        a ^=  (a>>16);
        return a;
}

static int fons__mini(int a, int b)
{
        return a < b ? a : b;
}

static int fons__maxi(int a, int b)
{
        return a > b ? a : b;
}

struct FONSglyph
{
        unsigned int codepoint;
        int index;
        int next;
        short size, blur;
        short x0,y0,x1,y1;
        short xadv,xoff,yoff;
};
typedef struct FONSglyph FONSglyph;

struct FONSfont
{
        FONSttFontImpl font;
        char name[64];
        unsigned char* data;
        int dataSize;
        unsigned char freeData;
        float ascender;
        float descender;
        float lineh;
        FONSglyph* glyphs;
        int cglyphs;
        int nglyphs;
        int lut[FONS_HASH_LUT_SIZE];
        int fallbacks[FONS_MAX_FALLBACKS];
        int nfallbacks;
};
typedef struct FONSfont FONSfont;

struct FONSstate
{
        int font;
        int align;
        float size;
        unsigned int color;
        float blur;
        float spacing;
};
typedef struct FONSstate FONSstate;

struct FONSatlasNode {
    short x, y, width;
};
typedef struct FONSatlasNode FONSatlasNode;

struct FONSatlas
{
        int width, height;
        FONSatlasNode* nodes;
        int nnodes;
        int cnodes;
};
typedef struct FONSatlas FONSatlas;

struct FONScontext
{
        FONSparams params;
        float itw,ith;
        unsigned char* texData;
        int dirtyRect[4];
        FONSfont** fonts;
        FONSatlas* atlas;
        int cfonts;
        int nfonts;
        float verts[FONS_VERTEX_COUNT*2];
        float tcoords[FONS_VERTEX_COUNT*2];
        unsigned int colors[FONS_VERTEX_COUNT];
        int nverts;
        unsigned char* scratch;
        int nscratch;
        FONSstate states[FONS_MAX_STATES];
        int nstates;
        void (*handleError)(void* uptr, int error, int val);
        void* errorUptr;
#ifdef FONS_USE_FREETYPE
        FT_Library ftLibrary;
#endif
};

#ifdef FONS_USE_FREETYPE

int fons__tt_init(FONScontext *context)
{
        FT_Error ftError;
        ftError = FT_Init_FreeType(&context->ftLibrary);
        return ftError == 0;
}

int fons__tt_done(FONScontext *context)
{
        FT_Error ftError;
        ftError = FT_Done_FreeType(context->ftLibrary);
        return ftError == 0;
}

int fons__tt_loadFont(FONScontext *context, FONSttFontImpl *font, unsigned char *data, int dataSize, int fontIndex)
{
        FT_Error ftError;

        //font->font.userdata = stash;
        ftError = FT_New_Memory_Face(context->ftLibrary, (const FT_Byte*)data, dataSize, fontIndex, &font->font);
        return ftError == 0;
}

void fons__tt_getFontVMetrics(FONSttFontImpl *font, int *ascent, int *descent, int *lineGap)
{
        *ascent = font->font->ascender;
        *descent = font->font->descender;
        *lineGap = font->font->height - (*ascent - *descent);
}

float fons__tt_getPixelHeightScale(FONSttFontImpl *font, float size)
{
#if 1
        // Note(DPF) maintain pixel-based units for compat after nanovg update
        return size / (font->font->ascender - font->font->descender);
#else
        return size / font->font->units_per_EM;
#endif
}

int fons__tt_getGlyphIndex(FONSttFontImpl *font, int codepoint)
{
        return FT_Get_Char_Index(font->font, codepoint);
}

int fons__tt_buildGlyphBitmap(FONSttFontImpl *font, int glyph, float size, float scale,
                                                          int *advance, int *lsb, int *x0, int *y0, int *x1, int *y1)
{
        FT_Error ftError;
        FT_GlyphSlot ftGlyph;
        FT_Fixed advFixed;
        FONS_NOTUSED(scale);

#if 1
        // Note(DPF) maintain pixel-based units for compat after nanovg update
        ftError = FT_Set_Pixel_Sizes(font->font, 0, (FT_UInt)(size * (float)font->font->units_per_EM / (float)(font->font->ascender - font->font->descender)));
#else
        ftError = FT_Set_Pixel_Sizes(font->font, 0, size);
#endif
        if (ftError) return 0;
#if 1
        // Note(DPF) maintain pixel-based units for compat after nanovg update
        ftError = FT_Load_Glyph(font->font, glyph, FT_LOAD_RENDER);
#else
        ftError = FT_Load_Glyph(font->font, glyph, FT_LOAD_RENDER | FT_LOAD_FORCE_AUTOHINT);
#endif
        if (ftError) return 0;
        ftError = FT_Get_Advance(font->font, glyph, FT_LOAD_NO_SCALE, &advFixed);
        if (ftError) return 0;
        ftGlyph = font->font->glyph;
        *advance = (int)advFixed;
        *lsb = (int)ftGlyph->metrics.horiBearingX;
        *x0 = ftGlyph->bitmap_left;
        *x1 = *x0 + ftGlyph->bitmap.width;
        *y0 = -ftGlyph->bitmap_top;
        *y1 = *y0 + ftGlyph->bitmap.rows;
        return 1;
}

void fons__tt_renderGlyphBitmap(FONSttFontImpl *font, unsigned char *output, int outWidth, int outHeight, int outStride,
                                                                float scaleX, float scaleY, int glyph)
{
        FT_GlyphSlot ftGlyph = font->font->glyph;
        int ftGlyphOffset = 0;
        unsigned int x, y;
        FONS_NOTUSED(outWidth);
        FONS_NOTUSED(outHeight);
        FONS_NOTUSED(scaleX);
        FONS_NOTUSED(scaleY);
        FONS_NOTUSED(glyph);    // glyph has already been loaded by fons__tt_buildGlyphBitmap

        for ( y = 0; y < ftGlyph->bitmap.rows; y++ ) {
                for ( x = 0; x < ftGlyph->bitmap.width; x++ ) {
                        output[(y * outStride) + x] = ftGlyph->bitmap.buffer[ftGlyphOffset++];
                }
        }
}

int fons__tt_getGlyphKernAdvance(FONSttFontImpl *font, int glyph1, int glyph2)
{
        FT_Vector ftKerning;
        FT_Get_Kerning(font->font, glyph1, glyph2, FT_KERNING_DEFAULT, &ftKerning);
        return (int)((ftKerning.x + 32) >> 6);  // Round up and convert to integer
}

#else

int fons__tt_init(FONScontext *context)
{
        FONS_NOTUSED(context);
        return 1;
}

int fons__tt_done(FONScontext *context)
{
        FONS_NOTUSED(context);
        return 1;
}

int fons__tt_loadFont(FONScontext *context, FONSttFontImpl *font, unsigned char *data, int dataSize, int fontIndex)
{
        int offset, stbError;
        FONS_NOTUSED(dataSize);

        font->font.userdata = context;
        offset = stbtt_GetFontOffsetForIndex(data, fontIndex);
        if (offset == -1) {
                stbError = 0;
        } else {
                stbError = stbtt_InitFont(&font->font, data, offset);
        }
        return stbError;
}

void fons__tt_getFontVMetrics(FONSttFontImpl *font, int *ascent, int *descent, int *lineGap)
{
        stbtt_GetFontVMetrics(&font->font, ascent, descent, lineGap);
}

float fons__tt_getPixelHeightScale(FONSttFontImpl *font, float size)
{
#if 1
        // Note(DPF) maintain pixel-based units for compat after nanovg update
        return stbtt_ScaleForPixelHeight(&font->font, size);
#else
        return stbtt_ScaleForMappingEmToPixels(&font->font, size);
#endif
}

int fons__tt_getGlyphIndex(FONSttFontImpl *font, int codepoint)
{
        return stbtt_FindGlyphIndex(&font->font, codepoint);
}

int fons__tt_buildGlyphBitmap(FONSttFontImpl *font, int glyph, float size, float scale,
                                                          int *advance, int *lsb, int *x0, int *y0, int *x1, int *y1)
{
        FONS_NOTUSED(size);
        stbtt_GetGlyphHMetrics(&font->font, glyph, advance, lsb);
        stbtt_GetGlyphBitmapBox(&font->font, glyph, scale, scale, x0, y0, x1, y1);
        return 1;
}

void fons__tt_renderGlyphBitmap(FONSttFontImpl *font, unsigned char *output, int outWidth, int outHeight, int outStride,
                                                                float scaleX, float scaleY, int glyph)
{
        stbtt_MakeGlyphBitmap(&font->font, output, outWidth, outHeight, outStride, scaleX, scaleY, glyph);
}

int fons__tt_getGlyphKernAdvance(FONSttFontImpl *font, int glyph1, int glyph2)
{
        return stbtt_GetGlyphKernAdvance(&font->font, glyph1, glyph2);
}

#endif

#ifdef STB_TRUETYPE_IMPLEMENTATION

static void* fons__tmpalloc(size_t size, void* up)
{
        unsigned char* ptr;
        FONScontext* stash = (FONScontext*)up;

        // 16-byte align the returned pointer
        size = (size + 0xf) & ~0xf;

        if (stash->nscratch+(int)size > FONS_SCRATCH_BUF_SIZE) {
                if (stash->handleError)
                        stash->handleError(stash->errorUptr, FONS_SCRATCH_FULL, stash->nscratch+(int)size);
                return NULL;
        }
        ptr = stash->scratch + stash->nscratch;
        stash->nscratch += (int)size;
        return ptr;
}

static void fons__tmpfree(void* ptr, void* up)
{
        (void)ptr;
        (void)up;
        // empty
}

#endif // STB_TRUETYPE_IMPLEMENTATION

// Copyright (c) 2008-2010 Bjoern Hoehrmann <bjoern@hoehrmann.de>
// See http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.

#define FONS_UTF8_ACCEPT 0
#define FONS_UTF8_REJECT 12

static unsigned int fons__decutf8(unsigned int* state, unsigned int* codep, unsigned int byte)
{
        static const unsigned char utf8d[] = {
                // The first part of the table maps bytes to character classes that
                // to reduce the size of the transition table and create bitmasks.
                0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
                1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,  9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
                8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
                10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8,

                // The second part is a transition table that maps a combination
                // of a state of the automaton and a character class to a state.
                0,12,24,36,60,96,84,12,12,12,48,72, 12,12,12,12,12,12,12,12,12,12,12,12,
                12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12,
                12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12,
                12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12,
                12,36,12,12,12,12,12,12,12,12,12,12,
    };

        unsigned int type = utf8d[byte];

    *codep = (*state != FONS_UTF8_ACCEPT) ?
                (byte & 0x3fu) | (*codep << 6) :
                (0xff >> type) & (byte);

        *state = utf8d[256 + *state + type];
        return *state;
}

// Atlas based on Skyline Bin Packer by Jukka Jylänki

static void fons__deleteAtlas(FONSatlas* atlas)
{
        if (atlas == NULL) return;
        if (atlas->nodes != NULL) free(atlas->nodes);
        free(atlas);
}

static FONSatlas* fons__allocAtlas(int w, int h, int nnodes)
{
        FONSatlas* atlas = NULL;

        // Allocate memory for the font stash.
        atlas = (FONSatlas*)malloc(sizeof(FONSatlas));
        if (atlas == NULL) goto error;
        memset(atlas, 0, sizeof(FONSatlas));

        atlas->width = w;
        atlas->height = h;

        // Allocate space for skyline nodes
        atlas->nodes = (FONSatlasNode*)malloc(sizeof(FONSatlasNode) * nnodes);
        if (atlas->nodes == NULL) goto error;
        memset(atlas->nodes, 0, sizeof(FONSatlasNode) * nnodes);
        atlas->nnodes = 0;
        atlas->cnodes = nnodes;

        // Init root node.
        atlas->nodes[0].x = 0;
        atlas->nodes[0].y = 0;
        atlas->nodes[0].width = (short)w;
        atlas->nnodes++;

        return atlas;

error:
        if (atlas) fons__deleteAtlas(atlas);
        return NULL;
}

static int fons__atlasInsertNode(FONSatlas* atlas, int idx, int x, int y, int w)
{
        int i;
        // Insert node
        if (atlas->nnodes+1 > atlas->cnodes) {
                atlas->cnodes = atlas->cnodes == 0 ? 8 : atlas->cnodes * 2;
                atlas->nodes = (FONSatlasNode*)realloc(atlas->nodes, sizeof(FONSatlasNode) * atlas->cnodes);
                if (atlas->nodes == NULL)
                        return 0;
        }
        for (i = atlas->nnodes; i > idx; i--)
                atlas->nodes[i] = atlas->nodes[i-1];
        atlas->nodes[idx].x = (short)x;
        atlas->nodes[idx].y = (short)y;
        atlas->nodes[idx].width = (short)w;
        atlas->nnodes++;

        return 1;
}

static void fons__atlasRemoveNode(FONSatlas* atlas, int idx)
{
        int i;
        if (atlas->nnodes == 0) return;
        for (i = idx; i < atlas->nnodes-1; i++)
                atlas->nodes[i] = atlas->nodes[i+1];
        atlas->nnodes--;
}

static void fons__atlasExpand(FONSatlas* atlas, int w, int h)
{
        // Insert node for empty space
        if (w > atlas->width)
                fons__atlasInsertNode(atlas, atlas->nnodes, atlas->width, 0, w - atlas->width);
        atlas->width = w;
        atlas->height = h;
}

static void fons__atlasReset(FONSatlas* atlas, int w, int h)
{
        atlas->width = w;
        atlas->height = h;
        atlas->nnodes = 0;

        // Init root node.
        atlas->nodes[0].x = 0;
        atlas->nodes[0].y = 0;
        atlas->nodes[0].width = (short)w;
        atlas->nnodes++;
}

static int fons__atlasAddSkylineLevel(FONSatlas* atlas, int idx, int x, int y, int w, int h)
{
        int i;

        // Insert new node
        if (fons__atlasInsertNode(atlas, idx, x, y+h, w) == 0)
                return 0;

        // Delete skyline segments that fall under the shadow of the new segment.
        for (i = idx+1; i < atlas->nnodes; i++) {
                if (atlas->nodes[i].x < atlas->nodes[i-1].x + atlas->nodes[i-1].width) {
                        int shrink = atlas->nodes[i-1].x + atlas->nodes[i-1].width - atlas->nodes[i].x;
                        atlas->nodes[i].x += (short)shrink;
                        atlas->nodes[i].width -= (short)shrink;
                        if (atlas->nodes[i].width <= 0) {
                                fons__atlasRemoveNode(atlas, i);
                                i--;
                        } else {
                                break;
                        }
                } else {
                        break;
                }
        }

        // Merge same height skyline segments that are next to each other.
        for (i = 0; i < atlas->nnodes-1; i++) {
                if (atlas->nodes[i].y == atlas->nodes[i+1].y) {
                        atlas->nodes[i].width += atlas->nodes[i+1].width;
                        fons__atlasRemoveNode(atlas, i+1);
                        i--;
                }
        }

        return 1;
}

static int fons__atlasRectFits(FONSatlas* atlas, int i, int w, int h)
{
        // Checks if there is enough space at the location of skyline span 'i',
        // and return the max height of all skyline spans under that at that location,
        // (think tetris block being dropped at that position). Or -1 if no space found.
        int x = atlas->nodes[i].x;
        int y = atlas->nodes[i].y;
        int spaceLeft;
        if (x + w > atlas->width)
                return -1;
        spaceLeft = w;
        while (spaceLeft > 0) {
                if (i == atlas->nnodes) return -1;
                y = fons__maxi(y, atlas->nodes[i].y);
                if (y + h > atlas->height) return -1;
                spaceLeft -= atlas->nodes[i].width;
                ++i;
        }
        return y;
}

static int fons__atlasAddRect(FONSatlas* atlas, int rw, int rh, int* rx, int* ry)
{
        int besth = atlas->height, bestw = atlas->width, besti = -1;
        int bestx = -1, besty = -1, i;

        // Bottom left fit heuristic.
        for (i = 0; i < atlas->nnodes; i++) {
                int y = fons__atlasRectFits(atlas, i, rw, rh);
                if (y != -1) {
                        if (y + rh < besth || (y + rh == besth && atlas->nodes[i].width < bestw)) {
                                besti = i;
                                bestw = atlas->nodes[i].width;
                                besth = y + rh;
                                bestx = atlas->nodes[i].x;
                                besty = y;
                        }
                }
        }

        if (besti == -1)
                return 0;

        // Perform the actual packing.
        if (fons__atlasAddSkylineLevel(atlas, besti, bestx, besty, rw, rh) == 0)
                return 0;

        *rx = bestx;
        *ry = besty;

        return 1;
}

static void fons__addWhiteRect(FONScontext* stash, int w, int h)
{
        int x, y, gx, gy;
        unsigned char* dst;
        if (fons__atlasAddRect(stash->atlas, w, h, &gx, &gy) == 0)
                return;

        // Rasterize
        dst = &stash->texData[gx + gy * stash->params.width];
        for (y = 0; y < h; y++) {
                for (x = 0; x < w; x++)
                        dst[x] = 0xff;
                dst += stash->params.width;
        }

        stash->dirtyRect[0] = fons__mini(stash->dirtyRect[0], gx);
        stash->dirtyRect[1] = fons__mini(stash->dirtyRect[1], gy);
        stash->dirtyRect[2] = fons__maxi(stash->dirtyRect[2], gx+w);
        stash->dirtyRect[3] = fons__maxi(stash->dirtyRect[3], gy+h);
}

FONScontext* fonsCreateInternal(FONSparams* params)
{
        FONScontext* stash = NULL;

        // Allocate memory for the font stash.
        stash = (FONScontext*)malloc(sizeof(FONScontext));
        if (stash == NULL) goto error;
        memset(stash, 0, sizeof(FONScontext));

        stash->params = *params;

        // Allocate scratch buffer.
        stash->scratch = (unsigned char*)malloc(FONS_SCRATCH_BUF_SIZE);
        if (stash->scratch == NULL) goto error;

        // Initialize implementation library
        if (!fons__tt_init(stash)) goto error;

        if (stash->params.renderCreate != NULL) {
                if (stash->params.renderCreate(stash->params.userPtr, stash->params.width, stash->params.height) == 0)
                        goto error;
        }

        stash->atlas = fons__allocAtlas(stash->params.width, stash->params.height, FONS_INIT_ATLAS_NODES);
        if (stash->atlas == NULL) goto error;

        // Allocate space for fonts.
        stash->fonts = (FONSfont**)malloc(sizeof(FONSfont*) * FONS_INIT_FONTS);
        if (stash->fonts == NULL) goto error;
        memset(stash->fonts, 0, sizeof(FONSfont*) * FONS_INIT_FONTS);
        stash->cfonts = FONS_INIT_FONTS;
        stash->nfonts = 0;

        // Create texture for the cache.
        stash->itw = 1.0f/stash->params.width;
        stash->ith = 1.0f/stash->params.height;
        stash->texData = (unsigned char*)malloc(stash->params.width * stash->params.height);
        if (stash->texData == NULL) goto error;
        memset(stash->texData, 0, stash->params.width * stash->params.height);

        stash->dirtyRect[0] = stash->params.width;
        stash->dirtyRect[1] = stash->params.height;
        stash->dirtyRect[2] = 0;
        stash->dirtyRect[3] = 0;

        // Add white rect at 0,0 for debug drawing.
        fons__addWhiteRect(stash, 2,2);

        fonsPushState(stash);
        fonsClearState(stash);

        return stash;

error:
        fonsDeleteInternal(stash);
        return NULL;
}

static FONSstate* fons__getState(FONScontext* stash)
{
        return &stash->states[stash->nstates-1];
}

int fonsAddFallbackFont(FONScontext* stash, int base, int fallback)
{
        FONSfont* baseFont = stash->fonts[base];
        if (baseFont->nfallbacks < FONS_MAX_FALLBACKS) {
                baseFont->fallbacks[baseFont->nfallbacks++] = fallback;
                return 1;
        }
        return 0;
}

void fonsResetFallbackFont(FONScontext* stash, int base)
{
        int i;

        FONSfont* baseFont = stash->fonts[base];
        baseFont->nfallbacks = 0;
        baseFont->nglyphs = 0;
        for (i = 0; i < FONS_HASH_LUT_SIZE; i++)
                baseFont->lut[i] = -1;
}

void fonsSetSize(FONScontext* stash, float size)
{
        fons__getState(stash)->size = size;
}

void fonsSetColor(FONScontext* stash, unsigned int color)
{
        fons__getState(stash)->color = color;
}

void fonsSetSpacing(FONScontext* stash, float spacing)
{
        fons__getState(stash)->spacing = spacing;
}

void fonsSetBlur(FONScontext* stash, float blur)
{
        fons__getState(stash)->blur = blur;
}

void fonsSetAlign(FONScontext* stash, int align)
{
        fons__getState(stash)->align = align;
}

void fonsSetFont(FONScontext* stash, int font)
{
        fons__getState(stash)->font = font;
}

void fonsPushState(FONScontext* stash)
{
        if (stash->nstates >= FONS_MAX_STATES) {
                if (stash->handleError)
                        stash->handleError(stash->errorUptr, FONS_STATES_OVERFLOW, 0);
                return;
        }
        if (stash->nstates > 0)
                memcpy(&stash->states[stash->nstates], &stash->states[stash->nstates-1], sizeof(FONSstate));
        stash->nstates++;
}

void fonsPopState(FONScontext* stash)
{
        if (stash->nstates <= 1) {
                if (stash->handleError)
                        stash->handleError(stash->errorUptr, FONS_STATES_UNDERFLOW, 0);
                return;
        }
        stash->nstates--;
}

void fonsClearState(FONScontext* stash)
{
        FONSstate* state = fons__getState(stash);
        state->size = 12.0f;
        state->color = 0xffffffff;
        state->font = 0;
        state->blur = 0;
        state->spacing = 0;
        state->align = FONS_ALIGN_LEFT | FONS_ALIGN_BASELINE;
}

static void fons__freeFont(FONSfont* font)
{
        if (font == NULL) return;
        if (font->glyphs) free(font->glyphs);
        if (font->freeData && font->data) free(font->data);
        free(font);
}

static int fons__allocFont(FONScontext* stash)
{
        FONSfont* font = NULL;
        if (stash->nfonts+1 > stash->cfonts) {
                stash->cfonts = stash->cfonts == 0 ? 8 : stash->cfonts * 2;
                stash->fonts = (FONSfont**)realloc(stash->fonts, sizeof(FONSfont*) * stash->cfonts);
                if (stash->fonts == NULL)
                        return -1;
                for (int i=stash->nfonts; i<stash->cfonts; ++i)
                        stash->fonts[i] = NULL;
        }
        font = (FONSfont*)malloc(sizeof(FONSfont));
        if (font == NULL) goto error;
        memset(font, 0, sizeof(FONSfont));

        font->glyphs = (FONSglyph*)malloc(sizeof(FONSglyph) * FONS_INIT_GLYPHS);
        if (font->glyphs == NULL) goto error;
        font->cglyphs = FONS_INIT_GLYPHS;
        font->nglyphs = 0;

        stash->fonts[stash->nfonts++] = font;
        return stash->nfonts-1;

error:
        fons__freeFont(font);

        return FONS_INVALID;
}

int fonsAddFont(FONScontext* stash, const char* name, const char* path, int fontIndex)
{
        FILE* fp = 0;
        int dataSize = 0;
        size_t readed;
        unsigned char* data = NULL;

        // Read in the font data.
        fp = fopen(path, "rb");
        if (fp == NULL) goto error;
        fseek(fp,0,SEEK_END);
        dataSize = (int)ftell(fp);
        fseek(fp,0,SEEK_SET);
        data = (unsigned char*)malloc(dataSize);
        if (data == NULL) goto error;
        readed = fread(data, 1, dataSize, fp);
        fclose(fp);
        fp = 0;
        if (readed != (size_t)dataSize) goto error;

        return fonsAddFontMem(stash, name, data, dataSize, 1, fontIndex);

error:
        if (data) free(data);
        if (fp) fclose(fp);
        return FONS_INVALID;
}

int fonsAddFontMem(FONScontext* stash, const char* name, unsigned char* data, int dataSize, int freeData, int fontIndex)
{
        int i, ascent, descent, fh, lineGap;
        FONSfont* font;

        int idx = fons__allocFont(stash);
        if (idx == FONS_INVALID)
        {
                if (freeData && data) free(data);
                return FONS_INVALID;
        }

        font = stash->fonts[idx];

        strncpy(font->name, name, sizeof(font->name));
        font->name[sizeof(font->name)-1] = '\0';

        // Init hash lookup.
        for (i = 0; i < FONS_HASH_LUT_SIZE; ++i)
                font->lut[i] = -1;

        // Read in the font data.
        font->dataSize = dataSize;
        font->data = data;
        font->freeData = (unsigned char)freeData;

        // Init font
        stash->nscratch = 0;
        if (!fons__tt_loadFont(stash, &font->font, data, dataSize, fontIndex)) goto error;

        // Store normalized line height. The real line height is got
        // by multiplying the lineh by font size.
        fons__tt_getFontVMetrics( &font->font, &ascent, &descent, &lineGap);
        ascent += lineGap;
        fh = ascent - descent;
        font->ascender = (float)ascent / (float)fh;
        font->descender = (float)descent / (float)fh;
        font->lineh = font->ascender - font->descender;

        return idx;

error:
        fons__freeFont(font);
        stash->nfonts--;
        return FONS_INVALID;
}

int fonsGetFontByName(FONScontext* s, const char* name)
{
        int i;
        for (i = 0; i < s->nfonts; i++) {
                if (strcmp(s->fonts[i]->name, name) == 0)
                        return i;
        }
        return FONS_INVALID;
}


static FONSglyph* fons__allocGlyph(FONSfont* font)
{
        if (font->nglyphs+1 > font->cglyphs) {
                font->cglyphs = font->cglyphs == 0 ? 8 : font->cglyphs * 2;
                font->glyphs = (FONSglyph*)realloc(font->glyphs, sizeof(FONSglyph) * font->cglyphs);
                if (font->glyphs == NULL) return NULL;
                for (int i=font->nglyphs; i<font->cglyphs; ++i)
                        memset(&font->glyphs[i], 0, sizeof(*font->glyphs));
        }
        font->nglyphs++;
        return &font->glyphs[font->nglyphs-1];
}


// Based on Exponential blur, Jani Huhtanen, 2006

#define APREC 16
#define ZPREC 7

static void fons__blurCols(unsigned char* dst, int w, int h, int dstStride, int alpha)
{
        int x, y;
        for (y = 0; y < h; y++) {
                int z = 0; // force zero border
                for (x = 1; x < w; x++) {
                        z += (alpha * (((int)(dst[x]) << ZPREC) - z)) >> APREC;
                        dst[x] = (unsigned char)(z >> ZPREC);
                }
                dst[w-1] = 0; // force zero border
                z = 0;
                for (x = w-2; x >= 0; x--) {
                        z += (alpha * (((int)(dst[x]) << ZPREC) - z)) >> APREC;
                        dst[x] = (unsigned char)(z >> ZPREC);
                }
                dst[0] = 0; // force zero border
                dst += dstStride;
        }
}

static void fons__blurRows(unsigned char* dst, int w, int h, int dstStride, int alpha)
{
        int x, y;
        for (x = 0; x < w; x++) {
                int z = 0; // force zero border
                for (y = dstStride; y < h*dstStride; y += dstStride) {
                        z += (alpha * (((int)(dst[y]) << ZPREC) - z)) >> APREC;
                        dst[y] = (unsigned char)(z >> ZPREC);
                }
                dst[(h-1)*dstStride] = 0; // force zero border
                z = 0;
                for (y = (h-2)*dstStride; y >= 0; y -= dstStride) {
                        z += (alpha * (((int)(dst[y]) << ZPREC) - z)) >> APREC;
                        dst[y] = (unsigned char)(z >> ZPREC);
                }
                dst[0] = 0; // force zero border
                dst++;
        }
}


static void fons__blur(FONScontext* stash, unsigned char* dst, int w, int h, int dstStride, int blur)
{
        int alpha;
        float sigma;
        (void)stash;

        if (blur < 1)
                return;
        // Calculate the alpha such that 90% of the kernel is within the radius. (Kernel extends to infinity)
        sigma = (float)blur * 0.57735f; // 1 / sqrt(3)
        alpha = (int)((1<<APREC) * (1.0f - expf(-2.3f / (sigma+1.0f))));
        fons__blurRows(dst, w, h, dstStride, alpha);
        fons__blurCols(dst, w, h, dstStride, alpha);
        fons__blurRows(dst, w, h, dstStride, alpha);
        fons__blurCols(dst, w, h, dstStride, alpha);
//      fons__blurrows(dst, w, h, dstStride, alpha);
//      fons__blurcols(dst, w, h, dstStride, alpha);
}

static FONSglyph* fons__getGlyph(FONScontext* stash, FONSfont* font, unsigned int codepoint,
                                                                 short isize, short iblur, int bitmapOption)
{
        int i, g, advance, lsb, x0, y0, x1, y1, gw, gh, gx, gy, x, y;
        float scale;
        FONSglyph* glyph = NULL;
        unsigned int h;
        float size = isize/10.0f;
        int pad, added;
        unsigned char* bdst;
        unsigned char* dst;
        FONSfont* renderFont = font;

        if (isize < 2) return NULL;
        if (iblur > 20) iblur = 20;
        pad = iblur+2;

        // Reset allocator.
        stash->nscratch = 0;

        // Find code point and size.
        h = fons__hashint(codepoint) & (FONS_HASH_LUT_SIZE-1);
        i = font->lut[h];
        while (i != -1) {
                if (font->glyphs[i].codepoint == codepoint && font->glyphs[i].size == isize && font->glyphs[i].blur == iblur) {
                        glyph = &font->glyphs[i];
                        if (bitmapOption == FONS_GLYPH_BITMAP_OPTIONAL || (glyph->x0 >= 0 && glyph->y0 >= 0)) {
                          return glyph;
                        }
                        // At this point, glyph exists but the bitmap data is not yet created.
                        break;
                }
                i = font->glyphs[i].next;
        }

        // Create a new glyph or rasterize bitmap data for a cached glyph.
        g = fons__tt_getGlyphIndex(&font->font, codepoint);
        // Try to find the glyph in fallback fonts.
        if (g == 0) {
                for (i = 0; i < font->nfallbacks; ++i) {
                        FONSfont* fallbackFont = stash->fonts[font->fallbacks[i]];
                        int fallbackIndex = fons__tt_getGlyphIndex(&fallbackFont->font, codepoint);
                        if (fallbackIndex != 0) {
                                g = fallbackIndex;
                                renderFont = fallbackFont;
                                break;
                        }
                }
                // It is possible that we did not find a fallback glyph.
                // In that case the glyph index 'g' is 0, and we'll proceed below and cache empty glyph.
        }
        scale = fons__tt_getPixelHeightScale(&renderFont->font, size);
        fons__tt_buildGlyphBitmap(&renderFont->font, g, size, scale, &advance, &lsb, &x0, &y0, &x1, &y1);
        gw = x1-x0 + pad*2;
        gh = y1-y0 + pad*2;

        // Determines the spot to draw glyph in the atlas.
        if (bitmapOption == FONS_GLYPH_BITMAP_REQUIRED) {
                // Find free spot for the rect in the atlas
                added = fons__atlasAddRect(stash->atlas, gw, gh, &gx, &gy);
                if (added == 0 && stash->handleError != NULL) {
                        // Atlas is full, let the user to resize the atlas (or not), and try again.
                        stash->handleError(stash->errorUptr, FONS_ATLAS_FULL, 0);
                        added = fons__atlasAddRect(stash->atlas, gw, gh, &gx, &gy);
                }
                if (added == 0) return NULL;
        } else {
                // Negative coordinate indicates there is no bitmap data created.
                gx = -1;
                gy = -1;
        }

        // Init glyph.
        if (glyph == NULL) {
                glyph = fons__allocGlyph(font);
                glyph->codepoint = codepoint;
                glyph->size = isize;
                glyph->blur = iblur;
                glyph->next = 0;

                // Insert char to hash lookup.
                glyph->next = font->lut[h];
                font->lut[h] = font->nglyphs-1;
        }
        glyph->index = g;
        glyph->x0 = (short)gx;
        glyph->y0 = (short)gy;
        glyph->x1 = (short)(glyph->x0+gw);
        glyph->y1 = (short)(glyph->y0+gh);
        glyph->xadv = (short)(scale * advance * 10.0f);
        glyph->xoff = (short)(x0 - pad);
        glyph->yoff = (short)(y0 - pad);

        if (bitmapOption == FONS_GLYPH_BITMAP_OPTIONAL) {
                return glyph;
        }

        // Rasterize
        dst = &stash->texData[(glyph->x0+pad) + (glyph->y0+pad) * stash->params.width];
        fons__tt_renderGlyphBitmap(&renderFont->font, dst, gw-pad*2,gh-pad*2, stash->params.width, scale, scale, g);

        // Make sure there is one pixel empty border.
        dst = &stash->texData[glyph->x0 + glyph->y0 * stash->params.width];
        for (y = 0; y < gh; y++) {
                dst[y*stash->params.width] = 0;
                dst[gw-1 + y*stash->params.width] = 0;
        }
        for (x = 0; x < gw; x++) {
                dst[x] = 0;
                dst[x + (gh-1)*stash->params.width] = 0;
        }

        // Debug code to color the glyph background
/*      unsigned char* fdst = &stash->texData[glyph->x0 + glyph->y0 * stash->params.width];
        for (y = 0; y < gh; y++) {
                for (x = 0; x < gw; x++) {
                        int a = (int)fdst[x+y*stash->params.width] + 20;
                        if (a > 255) a = 255;
                        fdst[x+y*stash->params.width] = a;
                }
        }*/

        // Blur
        if (iblur > 0) {
                stash->nscratch = 0;
                bdst = &stash->texData[glyph->x0 + glyph->y0 * stash->params.width];
                fons__blur(stash, bdst, gw, gh, stash->params.width, iblur);
        }

        stash->dirtyRect[0] = fons__mini(stash->dirtyRect[0], glyph->x0);
        stash->dirtyRect[1] = fons__mini(stash->dirtyRect[1], glyph->y0);
        stash->dirtyRect[2] = fons__maxi(stash->dirtyRect[2], glyph->x1);
        stash->dirtyRect[3] = fons__maxi(stash->dirtyRect[3], glyph->y1);

        return glyph;
}

static void fons__getQuad(FONScontext* stash, FONSfont* font,
                                                   int prevGlyphIndex, FONSglyph* glyph,
                                                   float scale, float spacing, float* x, float* y, FONSquad* q)
{
        float rx,ry,xoff,yoff,x0,y0,x1,y1;

        if (prevGlyphIndex != -1) {
                float adv = fons__tt_getGlyphKernAdvance(&font->font, prevGlyphIndex, glyph->index) * scale;
                *x += (int)(adv + spacing + 0.5f);
        }

        // Each glyph has 2px border to allow good interpolation,
        // one pixel to prevent leaking, and one to allow good interpolation for rendering.
        // Inset the texture region by one pixel for correct interpolation.
        xoff = (short)(glyph->xoff+1);
        yoff = (short)(glyph->yoff+1);
        x0 = (float)(glyph->x0+1);
        y0 = (float)(glyph->y0+1);
        x1 = (float)(glyph->x1-1);
        y1 = (float)(glyph->y1-1);

        if (stash->params.flags & FONS_ZERO_TOPLEFT) {
                rx = floorf(*x + xoff);
                ry = floorf(*y + yoff);

                q->x0 = rx;
                q->y0 = ry;
                q->x1 = rx + x1 - x0;
                q->y1 = ry + y1 - y0;

                q->s0 = x0 * stash->itw;
                q->t0 = y0 * stash->ith;
                q->s1 = x1 * stash->itw;
                q->t1 = y1 * stash->ith;
        } else {
                rx = floorf(*x + xoff);
                ry = floorf(*y - yoff);

                q->x0 = rx;
                q->y0 = ry;
                q->x1 = rx + x1 - x0;
                q->y1 = ry - y1 + y0;

                q->s0 = x0 * stash->itw;
                q->t0 = y0 * stash->ith;
                q->s1 = x1 * stash->itw;
                q->t1 = y1 * stash->ith;
        }

        *x += (int)(glyph->xadv / 10.0f + 0.5f);
}

static void fons__flush(FONScontext* stash)
{
        // Flush texture
        if (stash->dirtyRect[0] < stash->dirtyRect[2] && stash->dirtyRect[1] < stash->dirtyRect[3]) {
                if (stash->params.renderUpdate != NULL)
                        stash->params.renderUpdate(stash->params.userPtr, stash->dirtyRect, stash->texData);
                // Reset dirty rect
                stash->dirtyRect[0] = stash->params.width;
                stash->dirtyRect[1] = stash->params.height;
                stash->dirtyRect[2] = 0;
                stash->dirtyRect[3] = 0;
        }

        // Flush triangles
        if (stash->nverts > 0) {
                if (stash->params.renderDraw != NULL)
                        stash->params.renderDraw(stash->params.userPtr, stash->verts, stash->tcoords, stash->colors, stash->nverts);
                stash->nverts = 0;
        }
}

static __inline void fons__vertex(FONScontext* stash, float x, float y, float s, float t, unsigned int c)
{
        stash->verts[stash->nverts*2+0] = x;
        stash->verts[stash->nverts*2+1] = y;
        stash->tcoords[stash->nverts*2+0] = s;
        stash->tcoords[stash->nverts*2+1] = t;
        stash->colors[stash->nverts] = c;
        stash->nverts++;
}

static float fons__getVertAlign(FONScontext* stash, FONSfont* font, int align, short isize)
{
        if (stash->params.flags & FONS_ZERO_TOPLEFT) {
                if (align & FONS_ALIGN_TOP) {
                        return font->ascender * (float)isize/10.0f;
                } else if (align & FONS_ALIGN_MIDDLE) {
                        return (font->ascender + font->descender) / 2.0f * (float)isize/10.0f;
                } else if (align & FONS_ALIGN_BASELINE) {
                        return 0.0f;
                } else if (align & FONS_ALIGN_BOTTOM) {
                        return font->descender * (float)isize/10.0f;
                }
        } else {
                if (align & FONS_ALIGN_TOP) {
                        return -font->ascender * (float)isize/10.0f;
                } else if (align & FONS_ALIGN_MIDDLE) {
                        return -(font->ascender + font->descender) / 2.0f * (float)isize/10.0f;
                } else if (align & FONS_ALIGN_BASELINE) {
                        return 0.0f;
                } else if (align & FONS_ALIGN_BOTTOM) {
                        return -font->descender * (float)isize/10.0f;
                }
        }
        return 0.0;
}

float fonsDrawText(FONScontext* stash,
                                   float x, float y,
                                   const char* str, const char* end)
{
        FONSstate* state = fons__getState(stash);
        unsigned int codepoint;
        unsigned int utf8state = 0;
        FONSglyph* glyph = NULL;
        FONSquad q;
        int prevGlyphIndex = -1;
        short isize = (short)(state->size*10.0f);
        short iblur = (short)state->blur;
        float scale;
        FONSfont* font;
        float width;

        if (stash == NULL) return x;
        if (state->font < 0 || state->font >= stash->nfonts) return x;
        font = stash->fonts[state->font];
        if (font->data == NULL) return x;

        scale = fons__tt_getPixelHeightScale(&font->font, (float)isize/10.0f);

        if (end == NULL)
                end = str + strlen(str);

        // Align horizontally
        if (state->align & FONS_ALIGN_LEFT) {
                // empty
        } else if (state->align & FONS_ALIGN_RIGHT) {
                width = fonsTextBounds(stash, x,y, str, end, NULL);
                x -= width;
        } else if (state->align & FONS_ALIGN_CENTER) {
                width = fonsTextBounds(stash, x,y, str, end, NULL);
                x -= width * 0.5f;
        }
        // Align vertically.
        y += fons__getVertAlign(stash, font, state->align, isize);

        for (; str != end; ++str) {
                if (fons__decutf8(&utf8state, &codepoint, *(const unsigned char*)str))
                        continue;
                glyph = fons__getGlyph(stash, font, codepoint, isize, iblur, FONS_GLYPH_BITMAP_REQUIRED);
                if (glyph != NULL) {
                        fons__getQuad(stash, font, prevGlyphIndex, glyph, scale, state->spacing, &x, &y, &q);

                        if (stash->nverts+6 > FONS_VERTEX_COUNT)
                                fons__flush(stash);

                        fons__vertex(stash, q.x0, q.y0, q.s0, q.t0, state->color);
                        fons__vertex(stash, q.x1, q.y1, q.s1, q.t1, state->color);
                        fons__vertex(stash, q.x1, q.y0, q.s1, q.t0, state->color);

                        fons__vertex(stash, q.x0, q.y0, q.s0, q.t0, state->color);
                        fons__vertex(stash, q.x0, q.y1, q.s0, q.t1, state->color);
                        fons__vertex(stash, q.x1, q.y1, q.s1, q.t1, state->color);
                }
                prevGlyphIndex = glyph != NULL ? glyph->index : -1;
        }
        fons__flush(stash);

        return x;
}

int fonsTextIterInit(FONScontext* stash, FONStextIter* iter,
                                         float x, float y, const char* str, const char* end, int bitmapOption)
{
        FONSstate* state = fons__getState(stash);
        float width;

        memset(iter, 0, sizeof(*iter));

        if (stash == NULL) return 0;
        if (state->font < 0 || state->font >= stash->nfonts) return 0;
        iter->font = stash->fonts[state->font];
        if (iter->font->data == NULL) return 0;

        iter->isize = (short)(state->size*10.0f);
        iter->iblur = (short)state->blur;
        iter->scale = fons__tt_getPixelHeightScale(&iter->font->font, (float)iter->isize/10.0f);

        // Align horizontally
        if (state->align & FONS_ALIGN_LEFT) {
                // empty
        } else if (state->align & FONS_ALIGN_RIGHT) {
                width = fonsTextBounds(stash, x,y, str, end, NULL);
                x -= width;
        } else if (state->align & FONS_ALIGN_CENTER) {
                width = fonsTextBounds(stash, x,y, str, end, NULL);
                x -= width * 0.5f;
        }
        // Align vertically.
        y += fons__getVertAlign(stash, iter->font, state->align, iter->isize);

        if (end == NULL)
                end = str + strlen(str);

        iter->x = iter->nextx = x;
        iter->y = iter->nexty = y;
        iter->spacing = state->spacing;
        iter->str = str;
        iter->next = str;
        iter->end = end;
        iter->codepoint = 0;
        iter->prevGlyphIndex = -1;
        iter->bitmapOption = bitmapOption;

        return 1;
}

int fonsTextIterNext(FONScontext* stash, FONStextIter* iter, FONSquad* quad)
{
        FONSglyph* glyph = NULL;
        const char* str = iter->next;
        iter->str = iter->next;

        if (str == iter->end)
                return 0;

        for (; str != iter->end; str++) {
                if (fons__decutf8(&iter->utf8state, &iter->codepoint, *(const unsigned char*)str))
                        continue;
                str++;
                // Get glyph and quad
                iter->x = iter->nextx;
                iter->y = iter->nexty;
                glyph = fons__getGlyph(stash, iter->font, iter->codepoint, iter->isize, iter->iblur, iter->bitmapOption);
                // If the iterator was initialized with FONS_GLYPH_BITMAP_OPTIONAL, then the UV coordinates of the quad will be invalid.
                if (glyph != NULL)
                        fons__getQuad(stash, iter->font, iter->prevGlyphIndex, glyph, iter->scale, iter->spacing, &iter->nextx, &iter->nexty, quad);
                iter->prevGlyphIndex = glyph != NULL ? glyph->index : -1;
                break;
        }
        iter->next = str;

        return 1;
}

void fonsDrawDebug(FONScontext* stash, float x, float y)
{
        int i;
        int w = stash->params.width;
        int h = stash->params.height;
        float u = w == 0 ? 0 : (1.0f / w);
        float v = h == 0 ? 0 : (1.0f / h);

        if (stash->nverts+6+6 > FONS_VERTEX_COUNT)
                fons__flush(stash);

        // Draw background
        fons__vertex(stash, x+0, y+0, u, v, 0x0fffffff);
        fons__vertex(stash, x+w, y+h, u, v, 0x0fffffff);
        fons__vertex(stash, x+w, y+0, u, v, 0x0fffffff);

        fons__vertex(stash, x+0, y+0, u, v, 0x0fffffff);
        fons__vertex(stash, x+0, y+h, u, v, 0x0fffffff);
        fons__vertex(stash, x+w, y+h, u, v, 0x0fffffff);

        // Draw texture
        fons__vertex(stash, x+0, y+0, 0, 0, 0xffffffff);
        fons__vertex(stash, x+w, y+h, 1, 1, 0xffffffff);
        fons__vertex(stash, x+w, y+0, 1, 0, 0xffffffff);

        fons__vertex(stash, x+0, y+0, 0, 0, 0xffffffff);
        fons__vertex(stash, x+0, y+h, 0, 1, 0xffffffff);
        fons__vertex(stash, x+w, y+h, 1, 1, 0xffffffff);

        // Drawbug draw atlas
        for (i = 0; i < stash->atlas->nnodes; i++) {
                FONSatlasNode* n = &stash->atlas->nodes[i];

                if (stash->nverts+6 > FONS_VERTEX_COUNT)
                        fons__flush(stash);

                fons__vertex(stash, x+n->x+0, y+n->y+0, u, v, 0xc00000ff);
                fons__vertex(stash, x+n->x+n->width, y+n->y+1, u, v, 0xc00000ff);
                fons__vertex(stash, x+n->x+n->width, y+n->y+0, u, v, 0xc00000ff);

                fons__vertex(stash, x+n->x+0, y+n->y+0, u, v, 0xc00000ff);
                fons__vertex(stash, x+n->x+0, y+n->y+1, u, v, 0xc00000ff);
                fons__vertex(stash, x+n->x+n->width, y+n->y+1, u, v, 0xc00000ff);
        }

        fons__flush(stash);
}

float fonsTextBounds(FONScontext* stash,
                                         float x, float y,
                                         const char* str, const char* end,
                                         float* bounds)
{
        FONSstate* state = fons__getState(stash);
        unsigned int codepoint;
        unsigned int utf8state = 0;
        FONSquad q;
        FONSglyph* glyph = NULL;
        int prevGlyphIndex = -1;
        short isize = (short)(state->size*10.0f);
        short iblur = (short)state->blur;
        float scale;
        FONSfont* font;
        float startx, advance;
        float minx, miny, maxx, maxy;

        if (stash == NULL) return 0;
        if (state->font < 0 || state->font >= stash->nfonts) return 0;
        font = stash->fonts[state->font];
        if (font->data == NULL) return 0;

        scale = fons__tt_getPixelHeightScale(&font->font, (float)isize/10.0f);

        // Align vertically.
        y += fons__getVertAlign(stash, font, state->align, isize);

        minx = maxx = x;
        miny = maxy = y;
        startx = x;

        if (end == NULL)
                end = str + strlen(str);

        for (; str != end; ++str) {
                if (fons__decutf8(&utf8state, &codepoint, *(const unsigned char*)str))
                        continue;
                glyph = fons__getGlyph(stash, font, codepoint, isize, iblur, FONS_GLYPH_BITMAP_OPTIONAL);
                if (glyph != NULL) {
                        fons__getQuad(stash, font, prevGlyphIndex, glyph, scale, state->spacing, &x, &y, &q);
                        if (q.x0 < minx) minx = q.x0;
                        if (q.x1 > maxx) maxx = q.x1;
                        if (stash->params.flags & FONS_ZERO_TOPLEFT) {
                                if (q.y0 < miny) miny = q.y0;
                                if (q.y1 > maxy) maxy = q.y1;
                        } else {
                                if (q.y1 < miny) miny = q.y1;
                                if (q.y0 > maxy) maxy = q.y0;
                        }
                }
                prevGlyphIndex = glyph != NULL ? glyph->index : -1;
        }

        advance = x - startx;

        // Align horizontally
        if (state->align & FONS_ALIGN_LEFT) {
                // empty
        } else if (state->align & FONS_ALIGN_RIGHT) {
                minx -= advance;
                maxx -= advance;
        } else if (state->align & FONS_ALIGN_CENTER) {
                minx -= advance * 0.5f;
                maxx -= advance * 0.5f;
        }

        if (bounds) {
                bounds[0] = minx;
                bounds[1] = miny;
                bounds[2] = maxx;
                bounds[3] = maxy;
        }

        return advance;
}

void fonsVertMetrics(FONScontext* stash,
                                         float* ascender, float* descender, float* lineh)
{
        FONSfont* font;
        FONSstate* state = fons__getState(stash);
        short isize;

        if (stash == NULL) return;
        if (state->font < 0 || state->font >= stash->nfonts) return;
        font = stash->fonts[state->font];
        isize = (short)(state->size*10.0f);
        if (font->data == NULL) return;

        if (ascender)
                *ascender = font->ascender*isize/10.0f;
        if (descender)
                *descender = font->descender*isize/10.0f;
        if (lineh)
                *lineh = font->lineh*isize/10.0f;
}

void fonsLineBounds(FONScontext* stash, float y, float* miny, float* maxy)
{
        FONSfont* font;
        FONSstate* state = fons__getState(stash);
        short isize;

        if (stash == NULL) return;
        if (state->font < 0 || state->font >= stash->nfonts) return;
        font = stash->fonts[state->font];
        isize = (short)(state->size*10.0f);
        if (font->data == NULL) return;

        y += fons__getVertAlign(stash, font, state->align, isize);

        if (stash->params.flags & FONS_ZERO_TOPLEFT) {
                *miny = y - font->ascender * (float)isize/10.0f;
                *maxy = *miny + font->lineh*isize/10.0f;
        } else {
                *maxy = y + font->descender * (float)isize/10.0f;
                *miny = *maxy - font->lineh*isize/10.0f;
        }
}

const unsigned char* fonsGetTextureData(FONScontext* stash, int* width, int* height)
{
        if (width != NULL)
                *width = stash->params.width;
        if (height != NULL)
                *height = stash->params.height;
        return stash->texData;
}

int fonsValidateTexture(FONScontext* stash, int* dirty)
{
        if (stash->dirtyRect[0] < stash->dirtyRect[2] && stash->dirtyRect[1] < stash->dirtyRect[3]) {
                dirty[0] = stash->dirtyRect[0];
                dirty[1] = stash->dirtyRect[1];
                dirty[2] = stash->dirtyRect[2];
                dirty[3] = stash->dirtyRect[3];
                // Reset dirty rect
                stash->dirtyRect[0] = stash->params.width;
                stash->dirtyRect[1] = stash->params.height;
                stash->dirtyRect[2] = 0;
                stash->dirtyRect[3] = 0;
                return 1;
        }
        return 0;
}

void fonsDeleteInternal(FONScontext* stash)
{
        int i;
        if (stash == NULL) return;

        if (stash->params.renderDelete)
                stash->params.renderDelete(stash->params.userPtr);

        for (i = 0; i < stash->nfonts; ++i)
                fons__freeFont(stash->fonts[i]);

        if (stash->atlas) fons__deleteAtlas(stash->atlas);
        if (stash->fonts) free(stash->fonts);
        if (stash->texData) free(stash->texData);
        if (stash->scratch) free(stash->scratch);
        fons__tt_done(stash);
        free(stash);
}

void fonsSetErrorCallback(FONScontext* stash, void (*callback)(void* uptr, int error, int val), void* uptr)
{
        if (stash == NULL) return;
        stash->handleError = callback;
        stash->errorUptr = uptr;
}

void fonsGetAtlasSize(FONScontext* stash, int* width, int* height)
{
        if (stash == NULL) return;
        *width = stash->params.width;
        *height = stash->params.height;
}

int fonsExpandAtlas(FONScontext* stash, int width, int height)
{
        int i, maxy = 0;
        unsigned char* data = NULL;
        if (stash == NULL) return 0;

        width = fons__maxi(width, stash->params.width);
        height = fons__maxi(height, stash->params.height);

        if (width == stash->params.width && height == stash->params.height)
                return 1;

        // Flush pending glyphs.
        fons__flush(stash);

        // Create new texture
        if (stash->params.renderResize != NULL) {
                if (stash->params.renderResize(stash->params.userPtr, width, height) == 0)
                        return 0;
        }
        // Copy old texture data over.
        data = (unsigned char*)malloc(width * height);
        if (data == NULL)
                return 0;
        for (i = 0; i < stash->params.height; i++) {
                unsigned char* dst = &data[i*width];
                unsigned char* src = &stash->texData[i*stash->params.width];
                memcpy(dst, src, stash->params.width);
                if (width > stash->params.width)
                        memset(dst+stash->params.width, 0, width - stash->params.width);
        }
        if (height > stash->params.height)
                memset(&data[stash->params.height * width], 0, (height - stash->params.height) * width);

        free(stash->texData);
        stash->texData = data;

        // Increase atlas size
        fons__atlasExpand(stash->atlas, width, height);

        // Add existing data as dirty.
        for (i = 0; i < stash->atlas->nnodes; i++)
                maxy = fons__maxi(maxy, stash->atlas->nodes[i].y);
        stash->dirtyRect[0] = 0;
        stash->dirtyRect[1] = 0;
        stash->dirtyRect[2] = stash->params.width;
        stash->dirtyRect[3] = maxy;

        stash->params.width = width;
        stash->params.height = height;
        stash->itw = 1.0f/stash->params.width;
        stash->ith = 1.0f/stash->params.height;

        return 1;
}

int fonsResetAtlas(FONScontext* stash, int width, int height)
{
        int i, j;
        if (stash == NULL) return 0;

        // Flush pending glyphs.
        fons__flush(stash);

        // Create new texture
        if (stash->params.renderResize != NULL) {
                if (stash->params.renderResize(stash->params.userPtr, width, height) == 0)
                        return 0;
        }

        // Reset atlas
        fons__atlasReset(stash->atlas, width, height);

        // Clear texture data.
        stash->texData = (unsigned char*)realloc(stash->texData, width * height);
        if (stash->texData == NULL) return 0;
        memset(stash->texData, 0, width * height);

        // Reset dirty rect
        stash->dirtyRect[0] = width;
        stash->dirtyRect[1] = height;
        stash->dirtyRect[2] = 0;
        stash->dirtyRect[3] = 0;

        // Reset cached glyphs
        for (i = 0; i < stash->nfonts; i++) {
                FONSfont* font = stash->fonts[i];
                font->nglyphs = 0;
                for (j = 0; j < FONS_HASH_LUT_SIZE; j++)
                        font->lut[j] = -1;
        }

        stash->params.width = width;
        stash->params.height = height;
        stash->itw = 1.0f/stash->params.width;
        stash->ith = 1.0f/stash->params.height;

        // Add white rect at 0,0 for debug drawing.
        fons__addWhiteRect(stash, 2,2);

        return 1;
}


#endif