src/mesa/swrast/s_auxbuffer.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  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 #include "glheader.h"
  27 #include "imports.h"
  28
  29 #include "s_auxbuffer.h"
  30 #include "s_context.h"
  31
  32
  33
  34 /**
  35  * Allocate memory for the software auxillary buffers associated with
  36  * the given GLframebuffer.  Free any currently allocated aux buffers
  37  * first.
  38  */
  39 void
  40 _swrast_alloc_aux_buffers( GLframebuffer *buffer )
  41 {
  42    GLint i;
  43
  44    for (i = 0; i < buffer->Visual.numAuxBuffers; i++) {
  45       if (buffer->AuxBuffers[i]) {
  46          _mesa_free(buffer->AuxBuffers[i]);
  47          buffer->AuxBuffers[i] = NULL;
  48       }
  49
  50       buffer->AuxBuffers[i] = (GLchan *) _mesa_malloc(buffer->Width
  51                                         * buffer->Height * 4 * sizeof(GLchan));
  52    }
  53 }
  54
  55
  56
  57 /* RGBA */
  58 #define NAME(PREFIX) PREFIX##_aux
  59 #define SPAN_VARS \
  60    const SWcontext *swrast = SWRAST_CONTEXT(ctx);
  61 #define INIT_PIXEL_PTR(P, X, Y) \
  62    GLchan *P = swrast->CurAuxBuffer + ((Y) * ctx->DrawBuffer->Width + (X)) * 4; \
  63    assert(swrast->CurAuxBuffer);
  64
  65 #define INC_PIXEL_PTR(P) P += 4
  66 #if CHAN_TYPE == GL_FLOAT
  67 #define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
  68    P[0] = MAX2((R), 0.0F); \
  69    P[1] = MAX2((G), 0.0F); \
  70    P[2] = MAX2((B), 0.0F); \
  71    P[3] = CHAN_MAXF
  72 #define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
  73    P[0] = MAX2((R), 0.0F); \
  74    P[1] = MAX2((G), 0.0F); \
  75    P[2] = MAX2((B), 0.0F); \
  76    P[3] = CLAMP((A), 0.0F, CHAN_MAXF)
  77 #else
  78 #define STORE_RGB_PIXEL(P, X, Y, R, G, B) \
  79    P[0] = R;  P[1] = G;  P[2] = B;  P[3] = CHAN_MAX
  80 #define STORE_RGBA_PIXEL(P, X, Y, R, G, B, A) \
  81    P[0] = R;  P[1] = G;  P[2] = B;  P[3] = A
  82 #endif
  83 #define FETCH_RGBA_PIXEL(R, G, B, A, P) \
  84    R = P[0];  G = P[1];  B = P[2];  A = P[3]
  85 #include "swrast/s_spantemp.h"
  86
  87
  88
  89 /**
  90  * Called from driver's SetBuffer() function to choose an aux buffer.
  91  */
  92 void
  93 _swrast_use_aux_buffer(GLcontext *ctx, GLframebuffer *buffer, GLuint bufferBit)
  94 {
  95    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  96    (void) buffer;
  97
  98    switch (bufferBit) {
  99    case DD_AUX0_BIT:
 100       ASSERT(buffer->Visual.numAuxBuffers >= 1);
 101       swrast->CurAuxBuffer = ctx->DrawBuffer->AuxBuffers[0];
 102       break;
 103    case DD_AUX1_BIT:
 104       ASSERT(buffer->Visual.numAuxBuffers >= 2);
 105       swrast->CurAuxBuffer = ctx->DrawBuffer->AuxBuffers[1];
 106       break;
 107    case DD_AUX2_BIT:
 108       ASSERT(buffer->Visual.numAuxBuffers >= 3);
 109       swrast->CurAuxBuffer = ctx->DrawBuffer->AuxBuffers[2];
 110       break;
 111    case DD_AUX3_BIT:
 112       ASSERT(buffer->Visual.numAuxBuffers >= 4);
 113       swrast->CurAuxBuffer = ctx->DrawBuffer->AuxBuffers[3];
 114       break;
 115    default:
 116       swrast->CurAuxBuffer = NULL;
 117    }
 118
 119    swrast->Driver.WriteRGBASpan = write_rgba_span_aux;
 120    swrast->Driver.WriteRGBSpan = write_rgb_span_aux;
 121    swrast->Driver.WriteMonoRGBASpan = write_monorgba_span_aux;
 122    swrast->Driver.WriteRGBAPixels = write_rgba_pixels_aux;
 123    swrast->Driver.WriteMonoRGBAPixels = write_monorgba_pixels_aux;
 124    swrast->Driver.ReadRGBASpan = read_rgba_span_aux;
 125    swrast->Driver.ReadRGBAPixels = read_rgba_pixels_aux;
 126 }
 127