src/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 /*
  27  * Implement the effect of glColorMask and glIndexMask in software.
  28  */
  29
  30
  31 #include "main/glheader.h"
  32 #include "main/macros.h"
  33
  34 #include "s_context.h"
  35 #include "s_masking.h"
  36 #include "s_span.h"
  37
  38
  39 /**
  40  * Apply the color mask to a span of rgba values.
  41  */
  42 void
  43 _swrast_mask_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
  44                        SWspan *span, GLuint buf)
  45 {
  46    const GLuint n = span->end;
  47    void *rbPixels;
  48
  49    ASSERT(n < MAX_WIDTH);
  50    ASSERT(span->arrayMask & SPAN_RGBA);
  51    ASSERT(rb->DataType == span->array->ChanType);
  52
  53    rbPixels = _swrast_get_dest_rgba(ctx, rb, span);
  54
  55    /*
  56     * Do component masking.
  57     * Note that we're not using span->array->mask[] here.  We could...
  58     */
  59    if (span->array->ChanType == GL_UNSIGNED_BYTE) {
  60       /* treat 4xGLubyte as 1xGLuint */
  61       const GLuint srcMask = *((GLuint *) ctx->Color.ColorMask[buf]);
  62       const GLuint dstMask = ~srcMask;
  63       const GLuint *dst = (const GLuint *) rbPixels;
  64       GLuint *src = (GLuint *) span->array->rgba8;
  65       GLuint i;
  66       for (i = 0; i < n; i++) {
  67          src[i] = (src[i] & srcMask) | (dst[i] & dstMask);
  68       }
  69    }
  70    else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
  71       /* 2-byte components */
  72       /* XXX try to use 64-bit arithmetic someday */
  73       const GLushort rMask = ctx->Color.ColorMask[buf][RCOMP] ? 0xffff : 0x0;
  74       const GLushort gMask = ctx->Color.ColorMask[buf][GCOMP] ? 0xffff : 0x0;
  75       const GLushort bMask = ctx->Color.ColorMask[buf][BCOMP] ? 0xffff : 0x0;
  76       const GLushort aMask = ctx->Color.ColorMask[buf][ACOMP] ? 0xffff : 0x0;
  77       const GLushort (*dst)[4] = (const GLushort (*)[4]) rbPixels;
  78       GLushort (*src)[4] = span->array->rgba16;
  79       GLuint i;
  80       for (i = 0; i < n; i++) {
  81          src[i][RCOMP] = (src[i][RCOMP] & rMask) | (dst[i][RCOMP] & ~rMask);
  82          src[i][GCOMP] = (src[i][GCOMP] & gMask) | (dst[i][GCOMP] & ~gMask);
  83          src[i][BCOMP] = (src[i][BCOMP] & bMask) | (dst[i][BCOMP] & ~bMask);
  84          src[i][ACOMP] = (src[i][ACOMP] & aMask) | (dst[i][ACOMP] & ~aMask);
  85       }
  86    }
  87    else {
  88       /* 4-byte components */
  89       const GLuint rMask = ctx->Color.ColorMask[buf][RCOMP] ? ~0x0 : 0x0;
  90       const GLuint gMask = ctx->Color.ColorMask[buf][GCOMP] ? ~0x0 : 0x0;
  91       const GLuint bMask = ctx->Color.ColorMask[buf][BCOMP] ? ~0x0 : 0x0;
  92       const GLuint aMask = ctx->Color.ColorMask[buf][ACOMP] ? ~0x0 : 0x0;
  93       const GLuint (*dst)[4] = (const GLuint (*)[4]) rbPixels;
  94       GLuint (*src)[4] = (GLuint (*)[4]) span->array->attribs[FRAG_ATTRIB_COL0];
  95       GLuint i;
  96       for (i = 0; i < n; i++) {
  97          src[i][RCOMP] = (src[i][RCOMP] & rMask) | (dst[i][RCOMP] & ~rMask);
  98          src[i][GCOMP] = (src[i][GCOMP] & gMask) | (dst[i][GCOMP] & ~gMask);
  99          src[i][BCOMP] = (src[i][BCOMP] & bMask) | (dst[i][BCOMP] & ~bMask);
 100          src[i][ACOMP] = (src[i][ACOMP] & aMask) | (dst[i][ACOMP] & ~aMask);
 101       }
 102    }
 103 }
 104
 105
 106 /**
 107  * Apply the index mask to a span of color index values.
 108  */
 109 void
 110 _swrast_mask_ci_span(GLcontext *ctx, struct gl_renderbuffer *rb,
 111                      SWspan *span)
 112 {
 113    const GLuint srcMask = ctx->Color.IndexMask;
 114    const GLuint dstMask = ~srcMask;
 115    GLuint *index = span->array->index;
 116    GLuint dest[MAX_WIDTH];
 117    GLuint i;
 118
 119    ASSERT(span->arrayMask & SPAN_INDEX);
 120    ASSERT(span->end <= MAX_WIDTH);
 121    ASSERT(rb->DataType == GL_UNSIGNED_INT);
 122
 123    if (span->arrayMask & SPAN_XY) {
 124       _swrast_get_values(ctx, rb, span->end, span->array->x, span->array->y,
 125                          dest, sizeof(GLuint));
 126    }
 127    else {
 128       _swrast_read_index_span(ctx, rb, span->end, span->x, span->y, dest);
 129    }
 130
 131    for (i = 0; i < span->end; i++) {
 132       index[i] = (index[i] & srcMask) | (dest[i] & dstMask);
 133    }
 134 }