workbench/libs/cgfx/blttemplatealpha.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <aros/debug.h>
  10 #include <hidd/graphics.h>
  11 #include <proto/cybergraphics.h>
  12
  13 #include "cybergraphics_intern.h"
  14
  15 struct render_data
  16 {
  17     UBYTE *array;
  18     ULONG modulo;
  19     UBYTE invertalpha;
  20 };
  21
  22 static ULONG RenderHook(struct render_data *data, LONG srcx, LONG srcy,
  23     OOP_Object *dstbm_obj, OOP_Object *dst_gc, struct Rectangle *rect,
  24     struct GfxBase *GfxBase);
  25
  26 /*****************************************************************************
  27
  28     NAME */
  29 #include <proto/cybergraphics.h>
  30
  31         AROS_LH8(void, BltTemplateAlpha,
  32
  33 /*  SYNOPSIS */
  34         AROS_LHA(APTR             , src         , A0),
  35         AROS_LHA(LONG             , srcx        , D0),
  36         AROS_LHA(LONG             , srcmod      , D1),
  37         AROS_LHA(struct RastPort *, rp          , A1),
  38         AROS_LHA(LONG             , destx       , D2),
  39         AROS_LHA(LONG             , desty       , D3),
  40         AROS_LHA(LONG             , width       , D4),
  41         AROS_LHA(LONG             , height      , D5),
  42
  43 /*  LOCATION */
  44         struct Library *, CyberGfxBase, 37, Cybergraphics)
  45
  46 /*  FUNCTION
  47         Alpha blends the current foreground colour into a rectangular portion
  48         of a RastPort. The source alpha channel to use for each pixel is taken
  49         from an array of 8-bit alpha values. This alpha template may be any
  50         rectangle within a larger array/rectangle of alpha values.
  51
  52     INPUTS
  53         src - pointer to an array of source alpha values.
  54         srcx - byte/pixel offset of top-lefthand corner of alpha template.
  55         srcmod - the number of bytes in each row of the source array.
  56         rp - the RastPort to write to.
  57         destx, desty - top-lefthand corner of portion of destination RastPort
  58             to write to (in pixels).
  59         width, height - size of the area to copy (in pixels).
  60
  61     RESULT
  62         None.
  63
  64     NOTES
  65         The size and destination coordinates may be outside the RastPort
  66         boundaries, in which case the affected area is safely truncated.
  67
  68     EXAMPLE
  69
  70     BUGS
  71
  72     SEE ALSO
  73
  74     INTERNALS
  75
  76 *****************************************************************************/
  77 {
  78     AROS_LIBFUNC_INIT
  79
  80     struct render_data data;
  81     struct Rectangle rr;
  82
  83     if (width == 0 || height == 0)
  84         return;
  85
  86     /* This is cybergraphx. We only work wih HIDD bitmaps */
  87     if (!IS_HIDD_BM(rp->BitMap)) {
  88         D(bug("!!!!! Trying to use CGFX call on non-hidd bitmap "
  89             "in BltTemplateAlpha() !!!\n"));
  90         return;
  91     }
  92
  93     /* Compute the start of the array */
  94
  95     data.array  = src + srcx;
  96     data.modulo = srcmod;
  97     data.invertalpha = (rp->DrawMode & INVERSVID) ? TRUE : FALSE;
  98     rr.MinX = destx;
  99     rr.MinY = desty;
 100     rr.MaxX = destx + width  - 1;
 101     rr.MaxY = desty + height - 1;
 102
 103     DoRenderFunc(rp, NULL, &rr, RenderHook, &data, TRUE);
 104
 105     AROS_LIBFUNC_EXIT
 106 } /* BltTemplateAlpha */
 107
 108 static ULONG RenderHook(struct render_data *data, LONG srcx, LONG srcy,
 109     OOP_Object *dstbm_obj, OOP_Object *dst_gc, struct Rectangle *rect,
 110     struct GfxBase *GfxBase)
 111 {
 112     ULONG  width  = rect->MaxX - rect->MinX + 1;
 113     ULONG  height = rect->MaxY - rect->MinY + 1;
 114     UBYTE *array = data->array + data->modulo * srcy + srcx;
 115
 116     HIDD_BM_PutAlphaTemplate(dstbm_obj, dst_gc, array, data->modulo,
 117         rect->MinX, rect->MinY, width, height, data->invertalpha);
 118
 119     return width * height;
 120 }
 121