src/mesa/state_tracker/st_cb_get.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
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  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /**
  30  * glGet functions
  31  *
  32  * \author Brian Paul
  33  */
  34
  35 #include "main/imports.h"
  36 #include "main/context.h"
  37
  38 #include "pipe/p_defines.h"
  39
  40 #include "st_cb_fbo.h"
  41 #include "st_cb_get.h"
  42
  43
  44
  45 /**
  46  * Examine the current color read buffer format to determine
  47  * which GL pixel format/type combo is the best match.
  48  */
  49 static void
  50 get_preferred_read_format_type(GLcontext *ctx, GLint *format, GLint *type)
  51 {
  52    struct gl_framebuffer *fb = ctx->ReadBuffer;
  53    struct st_renderbuffer *strb = st_renderbuffer(fb->_ColorReadBuffer);
  54
  55    /* defaults */
  56    *format = ctx->Const.ColorReadFormat;
  57    *type = ctx->Const.ColorReadType;
  58
  59    if (strb) {
  60       /* XXX could add more cases here... */
  61       if (strb->format == PIPE_FORMAT_A8R8G8B8_UNORM) {
  62          *format = GL_BGRA;
  63          if (_mesa_little_endian())
  64             *type = GL_UNSIGNED_INT_8_8_8_8_REV;
  65          else
  66             *type = GL_UNSIGNED_INT_8_8_8_8;
  67       }
  68    }
  69 }
  70
  71
  72 /**
  73  * We only intercept the OES preferred ReadPixels format/type.
  74  * Everything else goes to the default _mesa_GetIntegerv.
  75  */
  76 static GLboolean
  77 st_GetIntegerv(GLcontext *ctx, GLenum pname, GLint *params)
  78 {
  79    GLint dummy;
  80
  81    switch (pname) {
  82    case GL_IMPLEMENTATION_COLOR_READ_TYPE_OES:
  83       get_preferred_read_format_type(ctx, &dummy, params);
  84       return GL_TRUE;
  85    case GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES:
  86       get_preferred_read_format_type(ctx, params, &dummy);
  87       return GL_TRUE;
  88    default:
  89       return GL_FALSE;
  90    }
  91 }
  92
  93
  94 void st_init_get_functions(struct dd_function_table *functions)
  95 {
  96    functions->GetIntegerv = st_GetIntegerv;
  97 }