native_client_sdk/src/examples/demo/life/life.c

   1 /* Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file.
   4  */
   5
   6 #include <assert.h>
   7 #include <math.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11
  12 #include "ppapi/c/pp_resource.h"
  13 #include "ppapi/c/ppb_core.h"
  14 #include "ppapi/c/ppb_fullscreen.h"
  15 #include "ppapi/c/ppb_graphics_2d.h"
  16 #include "ppapi/c/ppb_image_data.h"
  17 #include "ppapi/c/ppb_input_event.h"
  18 #include "ppapi/c/ppb_instance.h"
  19 #include "ppapi/c/ppb_view.h"
  20
  21 #include "ppapi_simple/ps_event.h"
  22 #include "ppapi_simple/ps_main.h"
  23
  24 PPB_Core* g_pCore;
  25 PPB_Fullscreen* g_pFullscreen;
  26 PPB_Graphics2D* g_pGraphics2D;
  27 PPB_ImageData* g_pImageData;
  28 PPB_Instance* g_pInstance;
  29 PPB_View* g_pView;
  30 PPB_InputEvent* g_pInputEvent;
  31 PPB_KeyboardInputEvent* g_pKeyboardInput;
  32 PPB_MouseInputEvent* g_pMouseInput;
  33 PPB_TouchInputEvent* g_pTouchInput;
  34
  35 struct {
  36   PP_Resource ctx;
  37   struct PP_Size size;
  38   int bound;
  39   uint8_t* cell_in;
  40   uint8_t* cell_out;
  41 } g_Context;
  42
  43
  44 const unsigned int kInitialRandSeed = 0xC0DE533D;
  45
  46 /* BGRA helper macro, for constructing a pixel for a BGRA buffer. */
  47 #define MakeBGRA(b, g, r, a)  \
  48   (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
  49
  50
  51 /*
  52  * Convert a count value into a live (green) or dead color value.
  53  */
  54 const uint32_t kNeighborColors[] = {
  55     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  56     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  57     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  58     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  59     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  60     MakeBGRA(0x00, 0xFF, 0x00, 0xFF),
  61     MakeBGRA(0x00, 0xFF, 0x00, 0xFF),
  62     MakeBGRA(0x00, 0xFF, 0x00, 0xFF),
  63     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  64     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  65     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  66     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  67     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  68     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  69     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  70     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  71     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  72     MakeBGRA(0x00, 0x00, 0x00, 0xFF),
  73 };
  74
  75 /*
  76  * These represent the new health value of a cell based on its neighboring
  77  * values.  The health is binary: either alive or dead.
  78  */
  79 const uint8_t kIsAlive[] = {
  80       0, 0, 0, 0, 0, 1, 1, 1, 0,
  81       0, 0, 0, 0, 0, 0, 0, 0, 0
  82 };
  83
  84 void UpdateContext(uint32_t width, uint32_t height) {
  85   if (width != g_Context.size.width || height != g_Context.size.height) {
  86     size_t size = width * height;
  87     size_t index;
  88
  89     free(g_Context.cell_in);
  90     free(g_Context.cell_out);
  91
  92     /* Create a new context */
  93     g_Context.cell_in = (uint8_t*) malloc(size);
  94     g_Context.cell_out = (uint8_t*) malloc(size);
  95
  96     memset(g_Context.cell_out, 0, size);
  97     for (index = 0; index < size; index++) {
  98       g_Context.cell_in[index] = rand() & 1;
  99     }
 100   }
 101
 102   /* Recreate the graphics context on a view change */
 103   g_pCore->ReleaseResource(g_Context.ctx);
 104   g_Context.size.width = width;
 105   g_Context.size.height = height;
 106   g_Context.ctx =
 107       g_pGraphics2D->Create(PSGetInstanceId(), &g_Context.size, PP_TRUE);
 108   g_Context.bound =
 109       g_pInstance->BindGraphics(PSGetInstanceId(), g_Context.ctx);
 110 }
 111
 112 void DrawCell(int32_t x, int32_t y) {
 113   int32_t width = g_Context.size.width;
 114   int32_t height = g_Context.size.height;
 115
 116   if (!g_Context.cell_in) return;
 117
 118   if (x > 0 && x < width - 1 && y > 0 && y < height - 1) {
 119     g_Context.cell_in[x - 1 + y * width] = 1;
 120     g_Context.cell_in[x + 1 + y * width] = 1;
 121     g_Context.cell_in[x + (y - 1) * width] = 1;
 122     g_Context.cell_in[x + (y + 1) * width] = 1;
 123   }
 124 }
 125
 126 void ProcessTouchEvent(PSEvent* event) {
 127   uint32_t count = g_pTouchInput->GetTouchCount(event->as_resource,
 128       PP_TOUCHLIST_TYPE_TOUCHES);
 129   uint32_t i, j;
 130   for (i = 0; i < count; i++) {
 131     struct PP_TouchPoint touch = g_pTouchInput->GetTouchByIndex(
 132         event->as_resource, PP_TOUCHLIST_TYPE_TOUCHES, i);
 133     int radius = (int)touch.radius.x;
 134     int x = (int)touch.position.x;
 135     int y = (int)touch.position.y;
 136     /* num = 1/100th the area of touch point */
 137     int num = (int)(M_PI * radius * radius / 100.0f);
 138     for (j = 0; j < num; j++) {
 139       int dx = rand() % (radius * 2) - radius;
 140       int dy = rand() % (radius * 2) - radius;
 141       /* only plot random cells within the touch area */
 142       if (dx * dx + dy * dy <= radius * radius)
 143         DrawCell(x + dx, y + dy);
 144     }
 145   }
 146 }
 147
 148 void ProcessEvent(PSEvent* event) {
 149   switch(event->type) {
 150     /* If the view updates, build a new Graphics 2D Context */
 151     case PSE_INSTANCE_DIDCHANGEVIEW: {
 152       struct PP_Rect rect;
 153
 154       g_pView->GetRect(event->as_resource, &rect);
 155       UpdateContext(rect.size.width, rect.size.height);
 156       break;
 157     }
 158
 159     case PSE_INSTANCE_HANDLEINPUT: {
 160       PP_InputEvent_Type type = g_pInputEvent->GetType(event->as_resource);
 161       PP_InputEvent_Modifier modifiers =
 162           g_pInputEvent->GetModifiers(event->as_resource);
 163
 164       switch(type) {
 165         case PP_INPUTEVENT_TYPE_MOUSEDOWN:
 166         case PP_INPUTEVENT_TYPE_MOUSEMOVE: {
 167           struct PP_Point location =
 168               g_pMouseInput->GetPosition(event->as_resource);
 169           /* If the button is down, draw */
 170           if (modifiers & PP_INPUTEVENT_MODIFIER_LEFTBUTTONDOWN) {
 171             DrawCell(location.x, location.y);
 172           }
 173           break;
 174         }
 175
 176         case PP_INPUTEVENT_TYPE_TOUCHSTART:
 177         case PP_INPUTEVENT_TYPE_TOUCHMOVE:
 178           ProcessTouchEvent(event);
 179           break;
 180
 181         case PP_INPUTEVENT_TYPE_KEYDOWN: {
 182           PP_Bool fullscreen = g_pFullscreen->IsFullscreen(PSGetInstanceId());
 183           g_pFullscreen->SetFullscreen(PSGetInstanceId(),
 184                                        fullscreen ? PP_FALSE : PP_TRUE);
 185           break;
 186         }
 187
 188         default:
 189           break;
 190       }
 191       /* case PSE_INSTANCE_HANDLEINPUT */
 192       break;
 193     }
 194
 195     default:
 196       break;
 197   }
 198 }
 199
 200
 201 void Stir(uint32_t width, uint32_t height) {
 202   int i;
 203   if (g_Context.cell_in == NULL || g_Context.cell_out == NULL)
 204     return;
 205
 206   for (i = 0; i < width; ++i) {
 207     g_Context.cell_in[i] = rand() & 1;
 208     g_Context.cell_in[i + (height - 1) * width] = rand() & 1;
 209   }
 210   for (i = 0; i < height; ++i) {
 211     g_Context.cell_in[i * width] = rand() & 1;
 212     g_Context.cell_in[i * width + (width - 1)] = rand() & 1;
 213   }
 214 }
 215
 216 void Render() {
 217   struct PP_Size* psize = &g_Context.size;
 218   PP_ImageDataFormat format = PP_IMAGEDATAFORMAT_BGRA_PREMUL;
 219
 220   /*
 221    * Create a buffer to draw into.  Since we are waiting until the next flush
 222    * chrome has an opportunity to cache this buffer see ppb_graphics_2d.h.
 223    */
 224   PP_Resource image =
 225       g_pImageData->Create(PSGetInstanceId(), format, psize, PP_FALSE);
 226   uint8_t* pixels = g_pImageData->Map(image);
 227
 228   struct PP_ImageDataDesc desc;
 229   uint8_t* cell_temp;
 230   uint32_t x, y;
 231
 232   /* If we somehow have not allocated these pointers yet, skip this frame. */
 233   if (!g_Context.cell_in || !g_Context.cell_out) return;
 234
 235   /* Get the stride. */
 236   g_pImageData->Describe(image, &desc);
 237
 238   /* Stir up the edges to prevent the simulation from reaching steady state. */
 239   Stir(desc.size.width, desc.size.height);
 240
 241   /* Do neighbor summation; apply rules, output pixel color. */
 242   for (y = 1; y < desc.size.height - 1; ++y) {
 243     uint8_t *src0 = (g_Context.cell_in + (y - 1) * desc.size.width) + 1;
 244     uint8_t *src1 = src0 + desc.size.width;
 245     uint8_t *src2 = src1 + desc.size.width;
 246     int count;
 247     uint32_t color;
 248     uint8_t *dst = (g_Context.cell_out + y * desc.size.width) + 1;
 249     uint32_t *pixel_line =  (uint32_t*) (pixels + y * desc.stride);
 250
 251     for (x = 1; x < (desc.size.width - 1); ++x) {
 252       /* Jitter and sum neighbors. */
 253       count = src0[-1] + src0[0] + src0[1] +
 254               src1[-1] +         + src1[1] +
 255               src2[-1] + src2[0] + src2[1];
 256       /* Include center cell. */
 257       count = count + count + src1[0];
 258       /* Use table lookup indexed by count to determine pixel & alive state. */
 259       color = kNeighborColors[count];
 260       *pixel_line++ = color;
 261       *dst++ = kIsAlive[count];
 262       ++src0;
 263       ++src1;
 264       ++src2;
 265     }
 266   }
 267
 268   cell_temp = g_Context.cell_in;
 269   g_Context.cell_in = g_Context.cell_out;
 270   g_Context.cell_out = cell_temp;
 271
 272   /* Unmap the range, we no longer need it. */
 273   g_pImageData->Unmap(image);
 274
 275   /* Replace the contexts, and block until it's on the screen. */
 276   g_pGraphics2D->ReplaceContents(g_Context.ctx, image);
 277   g_pGraphics2D->Flush(g_Context.ctx, PP_BlockUntilComplete());
 278
 279   /* Release the image data, we no longer need it. */
 280   g_pCore->ReleaseResource(image);
 281 }
 282
 283 /*
 284  * Starting point for the module.  We do not use main since it would
 285  * collide with main in libppapi_cpp.
 286  */
 287 int example_main(int argc, char *argv[]) {
 288   fprintf(stdout,"Started main.\n");
 289   g_pCore = (PPB_Core*)PSGetInterface(PPB_CORE_INTERFACE);
 290   g_pFullscreen = (PPB_Fullscreen*)PSGetInterface(PPB_FULLSCREEN_INTERFACE);
 291   g_pGraphics2D = (PPB_Graphics2D*)PSGetInterface(PPB_GRAPHICS_2D_INTERFACE);
 292   g_pInstance = (PPB_Instance*)PSGetInterface(PPB_INSTANCE_INTERFACE);
 293   g_pImageData = (PPB_ImageData*)PSGetInterface(PPB_IMAGEDATA_INTERFACE);
 294   g_pView = (PPB_View*)PSGetInterface(PPB_VIEW_INTERFACE);
 295
 296   g_pInputEvent =
 297       (PPB_InputEvent*) PSGetInterface(PPB_INPUT_EVENT_INTERFACE);
 298   g_pKeyboardInput = (PPB_KeyboardInputEvent*)
 299       PSGetInterface(PPB_KEYBOARD_INPUT_EVENT_INTERFACE);
 300   g_pMouseInput =
 301       (PPB_MouseInputEvent*) PSGetInterface(PPB_MOUSE_INPUT_EVENT_INTERFACE);
 302   g_pTouchInput =
 303       (PPB_TouchInputEvent*) PSGetInterface(PPB_TOUCH_INPUT_EVENT_INTERFACE);
 304
 305   PSEventSetFilter(PSE_ALL);
 306   while (1) {
 307     /* Process all waiting events without blocking */
 308     PSEvent* event;
 309     while ((event = PSEventTryAcquire()) != NULL) {
 310       ProcessEvent(event);
 311       PSEventRelease(event);
 312     }
 313
 314     /* Render a frame, blocking until complete. */
 315     if (g_Context.bound) {
 316       Render();
 317     }
 318   }
 319   return 0;
 320 }
 321
 322 /*
 323  * Register the function to call once the Instance Object is initialized.
 324  * see: pappi_simple/ps_main.h
 325  */
 326 PPAPI_SIMPLE_REGISTER_MAIN(example_main);