dll/opengl/mesa/swrast/s_masking.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /*
  26  * Implement the effect of glColorMask and glIndexMask in software.
  27  */
  28
  29 #include <precomp.h>
  30
  31 /**
  32  * Apply the color mask to a span of rgba values.
  33  */
  34 void
  35 _swrast_mask_rgba_span(struct gl_context *ctx, struct gl_renderbuffer *rb,
  36                        SWspan *span)
  37 {
  38    const GLuint n = span->end;
  39    void *rbPixels;
  40
  41    ASSERT(n < MAX_WIDTH);
  42    ASSERT(span->arrayMask & SPAN_RGBA);
  43
  44    rbPixels = _swrast_get_dest_rgba(ctx, rb, span);
  45
  46    /*
  47     * Do component masking.
  48     * Note that we're not using span->array->mask[] here.  We could...
  49     */
  50    if (span->array->ChanType == GL_UNSIGNED_BYTE) {
  51       /* treat 4xGLubyte as 1xGLuint */
  52       const GLuint srcMask = *((GLuint *) ctx->Color.ColorMask);
  53       const GLuint dstMask = ~srcMask;
  54       const GLuint *dst = (const GLuint *) rbPixels;
  55       GLuint *src = (GLuint *) span->array->rgba8;
  56       GLuint i;
  57       for (i = 0; i < n; i++) {
  58          src[i] = (src[i] & srcMask) | (dst[i] & dstMask);
  59       }
  60    }
  61    else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
  62       /* 2-byte components */
  63       /* XXX try to use 64-bit arithmetic someday */
  64       const GLushort rMask = ctx->Color.ColorMask[RCOMP] ? 0xffff : 0x0;
  65       const GLushort gMask = ctx->Color.ColorMask[GCOMP] ? 0xffff : 0x0;
  66       const GLushort bMask = ctx->Color.ColorMask[BCOMP] ? 0xffff : 0x0;
  67       const GLushort aMask = ctx->Color.ColorMask[ACOMP] ? 0xffff : 0x0;
  68       const GLushort (*dst)[4] = (const GLushort (*)[4]) rbPixels;
  69       GLushort (*src)[4] = span->array->rgba16;
  70       GLuint i;
  71       for (i = 0; i < n; i++) {
  72          src[i][RCOMP] = (src[i][RCOMP] & rMask) | (dst[i][RCOMP] & ~rMask);
  73          src[i][GCOMP] = (src[i][GCOMP] & gMask) | (dst[i][GCOMP] & ~gMask);
  74          src[i][BCOMP] = (src[i][BCOMP] & bMask) | (dst[i][BCOMP] & ~bMask);
  75          src[i][ACOMP] = (src[i][ACOMP] & aMask) | (dst[i][ACOMP] & ~aMask);
  76       }
  77    }
  78    else {
  79       /* 4-byte components */
  80       const GLuint rMask = ctx->Color.ColorMask[RCOMP] ? ~0x0 : 0x0;
  81       const GLuint gMask = ctx->Color.ColorMask[GCOMP] ? ~0x0 : 0x0;
  82       const GLuint bMask = ctx->Color.ColorMask[BCOMP] ? ~0x0 : 0x0;
  83       const GLuint aMask = ctx->Color.ColorMask[ACOMP] ? ~0x0 : 0x0;
  84       const GLuint (*dst)[4] = (const GLuint (*)[4]) rbPixels;
  85       GLuint (*src)[4] = (GLuint (*)[4]) span->array->attribs[FRAG_ATTRIB_COL];
  86       GLuint i;
  87       for (i = 0; i < n; i++) {
  88          src[i][RCOMP] = (src[i][RCOMP] & rMask) | (dst[i][RCOMP] & ~rMask);
  89          src[i][GCOMP] = (src[i][GCOMP] & gMask) | (dst[i][GCOMP] & ~gMask);
  90          src[i][BCOMP] = (src[i][BCOMP] & bMask) | (dst[i][BCOMP] & ~bMask);
  91          src[i][ACOMP] = (src[i][ACOMP] & aMask) | (dst[i][ACOMP] & ~aMask);
  92       }
  93    }
  94 }