src/mesa/state_tracker/st_copytex.c

/*
 * Copyright 2015 VMware, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include "main/mtypes.h"
#include "main/buffers.h"
#include "main/errors.h"
#include "main/fbobject.h"
#include "main/get.h"
#include "main/teximage.h"
#include "main/texparam.h"
#include "st_copytex.h"


/**
 * Copy a colorbuffer from the window system framebuffer (a window or
 * pbuffer) to a texture.
 * This is a helper used by the wglBindTexImageARB() function.
 *
 * \param srcBuffer  source buffer (GL_FRONT_LEFT, GL_BACK_LEFT, etc)
 * \param fbWidth  width of the source framebuffer
 * \param fbHeight  height of the source framebuffer
 * \param texTarget  which texture target to copy to (GL_TEXTURE_1D/2D/CUBE_MAP)
 * \param texLevel  which texture mipmap level to copy to
 * \param cubeFace  which cube face to copy to (in [0,5])
 * \param texFormat  what texture format to use, if texture doesn't exist
 */
void
st_copy_framebuffer_to_texture(GLenum srcBuffer,
                               GLint fbWidth, GLint fbHeight,
                               GLenum texTarget, GLint texLevel,
                               GLuint cubeFace, GLenum texFormat)
{
   GLint readFBOSave, readBufSave, width, height;

   assert(cubeFace < 6);

   /* Save current FBO / readbuffer */
   _mesa_GetIntegerv(GL_READ_FRAMEBUFFER_BINDING, &readFBOSave);
   _mesa_GetIntegerv(GL_READ_BUFFER, &readBufSave);

   /* Read from the winsys buffer */
   _mesa_BindFramebuffer(GL_READ_FRAMEBUFFER, 0);
   _mesa_ReadBuffer(srcBuffer);

   /* copy image from pbuffer to texture */
   switch (texTarget) {
   case GL_TEXTURE_1D:
      _mesa_GetTexLevelParameteriv(GL_TEXTURE_1D, texLevel,
                                   GL_TEXTURE_WIDTH, &width);
      if (width == fbWidth) {
         /* replace existing texture */
         _mesa_CopyTexSubImage1D(GL_TEXTURE_1D,
                                 texLevel,
                                 0,    /* xoffset */
                                 0, 0, /* x, y */
                                 fbWidth);
      } else {
         /* define initial texture */
         _mesa_CopyTexImage1D(GL_TEXTURE_1D,
                              texLevel,
                              texFormat,
                              0, 0, /* x, y */
                              fbWidth, 0);
      }
      break;
   case GL_TEXTURE_2D:
      _mesa_GetTexLevelParameteriv(GL_TEXTURE_2D, texLevel,
                                   GL_TEXTURE_WIDTH, &width);
      _mesa_GetTexLevelParameteriv(GL_TEXTURE_2D, texLevel,
                                   GL_TEXTURE_HEIGHT, &height);
      if (width == fbWidth && height == fbHeight) {
         /* replace existing texture */
         _mesa_CopyTexSubImage2D(GL_TEXTURE_2D,
                                 texLevel,
                                 0, 0, /* xoffset, yoffset */
                                 0, 0, /* x, y */
                                 fbWidth, fbHeight);
      } else {
         /* define initial texture */
         _mesa_CopyTexImage2D(GL_TEXTURE_2D,
                              texLevel,
                              texFormat,
                              0, 0, /* x, y */
                              fbWidth, fbHeight, 0);
      }
      break;
   case GL_TEXTURE_CUBE_MAP:
      {
         const GLenum target =
            GL_TEXTURE_CUBE_MAP_POSITIVE_X + cubeFace;
         _mesa_GetTexLevelParameteriv(target, texLevel,
                                      GL_TEXTURE_WIDTH, &width);
         _mesa_GetTexLevelParameteriv(target, texLevel,
                                      GL_TEXTURE_HEIGHT, &height);
         if (width == fbWidth && height == fbHeight) {
            /* replace existing texture */
            _mesa_CopyTexSubImage2D(target,
                                    texLevel,
                                    0, 0, /* xoffset, yoffset */
                                    0, 0, /* x, y */
                                    fbWidth, fbHeight);
         } else {
            /* define new texture */
            _mesa_CopyTexImage2D(target,
                                 texLevel,
                                 texFormat,
                                 0, 0, /* x, y */
                                 fbWidth, fbHeight, 0);
         }
      }
      break;
   default:
      _mesa_problem(NULL,
                    "unexpected target in st_copy_framebuffer_to_texture()\n");
   }

   /* restore readbuffer */
   _mesa_ReadBuffer(readBufSave);
   _mesa_BindFramebuffer(GL_READ_FRAMEBUFFER, readFBOSave);
}