fbobject.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

/*
 * Mesa 3-D graphics library
 * Version:  6.3
 *
 * Copyright (C) 1999-2005  Brian Paul   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
 * BRIAN PAUL 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.
 */


/*
 * Authors:
 *   Brian Paul
 */


#include "context.h"
#include "fbobject.h"
#include "framebuffer.h"
#include "hash.h"
#include "renderbuffer.h"
#include "teximage.h"
#include "texstore.h"


/**
 * Notes:
 *
 * None of the GL_EXT_framebuffer_object functions are compiled into
 * display lists.
 */



/*
 * When glGenRender/FramebuffersEXT() is called we insert pointers to
 * these placeholder objects into the hash table.
 * Later, when the object ID is first bound, we replace the placeholder
 * with the real frame/renderbuffer.
 */
static struct gl_framebuffer DummyFramebuffer;
static struct gl_renderbuffer DummyRenderbuffer;


#define IS_CUBE_FACE(TARGET) \
   ((TARGET) >= GL_TEXTURE_CUBE_MAP_POSITIVE_X && \
    (TARGET) <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z)


/**
 * Helper routine for getting a gl_renderbuffer.
 */
static struct gl_renderbuffer *
lookup_renderbuffer(GLcontext *ctx, GLuint id)
{
   struct gl_renderbuffer *rb;

   if (id == 0)
      return NULL;

   rb = (struct gl_renderbuffer *)
      _mesa_HashLookup(ctx->Shared->RenderBuffers, id);
   return rb;
}


/**
 * Helper routine for getting a gl_framebuffer.
 */
static struct gl_framebuffer *
lookup_framebuffer(GLcontext *ctx, GLuint id)
{
   struct gl_framebuffer *fb;

   if (id == 0)
      return NULL;

   fb = (struct gl_framebuffer *)
      _mesa_HashLookup(ctx->Shared->FrameBuffers, id);
   return fb;
}


/**
 * Given a GL_*_ATTACHMENTn token, return a pointer to the corresponding
 * gl_renderbuffer_attachment object.
 */
static struct gl_renderbuffer_attachment *
get_attachment(GLcontext *ctx, struct gl_framebuffer *fb, GLenum attachment)
{
   GLuint i;

   switch (attachment) {
   case GL_COLOR_ATTACHMENT0_EXT:
   case GL_COLOR_ATTACHMENT1_EXT:
   case GL_COLOR_ATTACHMENT2_EXT:
   case GL_COLOR_ATTACHMENT3_EXT:
   case GL_COLOR_ATTACHMENT4_EXT:
   case GL_COLOR_ATTACHMENT5_EXT:
   case GL_COLOR_ATTACHMENT6_EXT:
   case GL_COLOR_ATTACHMENT7_EXT:
   case GL_COLOR_ATTACHMENT8_EXT:
   case GL_COLOR_ATTACHMENT9_EXT:
   case GL_COLOR_ATTACHMENT10_EXT:
   case GL_COLOR_ATTACHMENT11_EXT:
   case GL_COLOR_ATTACHMENT12_EXT:
   case GL_COLOR_ATTACHMENT13_EXT:
   case GL_COLOR_ATTACHMENT14_EXT:
   case GL_COLOR_ATTACHMENT15_EXT:
      i = attachment - GL_COLOR_ATTACHMENT0_EXT;
      if (i >= ctx->Const.MaxColorAttachments) {
	 return NULL;
      }
      return &fb->Attachment[BUFFER_COLOR0 + i];
   case GL_DEPTH_ATTACHMENT_EXT:
      return &fb->Attachment[BUFFER_DEPTH];
   case GL_STENCIL_ATTACHMENT_EXT:
      return &fb->Attachment[BUFFER_STENCIL];
   default:
      return NULL;
   }
}


/**
 * Remove any texture or renderbuffer attached to the given attachment
 * point.  Update reference counts, etc.
 */
void
_mesa_remove_attachment(GLcontext *ctx, struct gl_renderbuffer_attachment *att)
{
   if (att->Type == GL_TEXTURE) {
      ASSERT(att->Texture);
      if (att->Renderbuffer) {
         /* delete/remove the 'wrapper' renderbuffer */
         /* XXX do we really want to do this??? */
         att->Renderbuffer->Delete(att->Renderbuffer);
         att->Renderbuffer = NULL;
      }
      att->Texture->RefCount--;
      if (att->Texture->RefCount == 0) {
	 ctx->Driver.DeleteTexture(ctx, att->Texture);
      }
      att->Texture = NULL;
   }
   else if (att->Type == GL_RENDERBUFFER_EXT) {
      ASSERT(att->Renderbuffer);
      ASSERT(!att->Texture);
      att->Renderbuffer->RefCount--;
      if (att->Renderbuffer->RefCount == 0) {
         att->Renderbuffer->Delete(att->Renderbuffer);
      }
      att->Renderbuffer = NULL;
   }
   att->Type = GL_NONE;
   att->Complete = GL_TRUE;
}


/**
 * Bind a texture object to an attachment point.
 * The previous binding, if any, will be removed first.
 */
void
_mesa_set_texture_attachment(GLcontext *ctx,
                             struct gl_renderbuffer_attachment *att,
                             struct gl_texture_object *texObj,
                             GLenum texTarget, GLuint level, GLuint zoffset)
{
   _mesa_remove_attachment(ctx, att);
   att->Type = GL_TEXTURE;
   att->Texture = texObj;
   att->TextureLevel = level;
   if (IS_CUBE_FACE(texTarget)) {
      att->CubeMapFace = texTarget - GL_TEXTURE_CUBE_MAP_POSITIVE_X;
   }
   else {
      att->CubeMapFace = 0;
   }
   att->Zoffset = zoffset;
   att->Complete = GL_FALSE;

   texObj->RefCount++;

   /* XXX when we attach to a texture, we should probably set the
    * att->Renderbuffer pointer to a "wrapper renderbuffer" which
    * makes the texture image look like renderbuffer.
    */
}


/**
 * Bind a renderbuffer to an attachment point.
 * The previous binding, if any, will be removed first.
 */
void
_mesa_set_renderbuffer_attachment(GLcontext *ctx,
                                  struct gl_renderbuffer_attachment *att,
                                  struct gl_renderbuffer *rb)
{
   _mesa_remove_attachment(ctx, att);
   att->Type = GL_RENDERBUFFER_EXT;
   att->Renderbuffer = rb;
   att->Texture = NULL; /* just to be safe */
   att->Complete = GL_FALSE;
   rb->RefCount++;
}


/**
 * Fallback for ctx->Driver.FramebufferRenderbuffer()
 * Sets a framebuffer attachment to a particular renderbuffer.
 * The framebuffer in question is ctx->DrawBuffer.
 * \sa _mesa_renderbuffer_texture
 */
void
_mesa_framebuffer_renderbuffer(GLcontext *ctx,
                               struct gl_renderbuffer_attachment *att,
                               struct gl_renderbuffer *rb)
{
   if (rb) {
      _mesa_set_renderbuffer_attachment(ctx, att, rb);
   }
   else {
      _mesa_remove_attachment(ctx, att);
   }
}


/**
 * Test if an attachment point is complete and update its Complete field.
 * \param format if GL_COLOR, this is a color attachment point,
 *               if GL_DEPTH, this is a depth component attachment point,
 *               if GL_STENCIL, this is a stencil component attachment point.
 */
static void
test_attachment_completeness(const GLcontext *ctx, GLenum format,
                             struct gl_renderbuffer_attachment *att)
{
   assert(format == GL_COLOR || format == GL_DEPTH || format == GL_STENCIL);

   /* assume complete */
   att->Complete = GL_TRUE;

   /* Look for reasons why the attachment might be incomplete */
   if (att->Type == GL_TEXTURE) {
      const struct gl_texture_object *texObj = att->Texture;
      struct gl_texture_image *texImage;

      if (!texObj) {
         att->Complete = GL_FALSE;
         return;
      }

      texImage = texObj->Image[att->CubeMapFace][att->TextureLevel];
      if (!texImage) {
         att->Complete = GL_FALSE;
         return;
      }
      if (texImage->Width < 1 || texImage->Height < 1) {
         att->Complete = GL_FALSE;
         return;
      }
      if (texObj->Target == GL_TEXTURE_3D && att->Zoffset >= texImage->Depth) {
         att->Complete = GL_FALSE;
         return;
      }

      if (format == GL_COLOR) {
         if (texImage->TexFormat->BaseFormat != GL_RGB &&
             texImage->TexFormat->BaseFormat != GL_RGBA) {
            att->Complete = GL_FALSE;
            return;
         }
      }
      else if (format == GL_DEPTH) {
         if (texImage->TexFormat->BaseFormat != GL_DEPTH_COMPONENT) {
            att->Complete = GL_FALSE;
            return;
         }
      }
      else {
         /* no such thing as stencil textures */
         att->Complete = GL_FALSE;
         return;
      }
   }
   else if (att->Type == GL_RENDERBUFFER_EXT) {
      if (att->Renderbuffer->Width < 1 || att->Renderbuffer->Height < 1) {
         att->Complete = GL_FALSE;
         return;
      }
      if (format == GL_COLOR) {
         if (att->Renderbuffer->_BaseFormat != GL_RGB &&
             att->Renderbuffer->_BaseFormat != GL_RGBA) {
            att->Complete = GL_FALSE;
            return;
         }
      }
      else if (format == GL_DEPTH) {
         if (att->Renderbuffer->_BaseFormat != GL_DEPTH_COMPONENT) {
            att->Complete = GL_FALSE;
            return;
         }
      }
      else {
         assert(format == GL_STENCIL);
         if (att->Renderbuffer->_BaseFormat != GL_STENCIL_INDEX) {
            att->Complete = GL_FALSE;
            return;
         }
      }
   }
   else {
      ASSERT(att->Type == GL_NONE);
      /* complete */
      return;
   }
}


/**
 * Test if the given framebuffer object is complete and update its
 * Status field with the results.
 * Also update the framebuffer's Width and Height fields if the
 * framebuffer is complete.
 */
void
_mesa_test_framebuffer_completeness(GLcontext *ctx, struct gl_framebuffer *fb)
{
   GLuint numImages, width = 0, height = 0;
   GLenum intFormat = GL_NONE;
   GLuint w = 0, h = 0;
   GLint i;

   assert(fb->Name != 0);

   numImages = 0;
   fb->Width = 0;
   fb->Height = 0;

   /* Start at -2 to more easily loop over all attachment points */
   for (i = -2; i < (GLint) ctx->Const.MaxColorAttachments; i++) {
      struct gl_renderbuffer_attachment *att;
      GLenum f;

      if (i == -2) {
         att = &fb->Attachment[BUFFER_DEPTH];
         test_attachment_completeness(ctx, GL_DEPTH, att);
         if (!att->Complete) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT;
            return;
         }
      }
      else if (i == -1) {
         att = &fb->Attachment[BUFFER_STENCIL];
         test_attachment_completeness(ctx, GL_STENCIL, att);
         if (!att->Complete) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT;
            return;
         }
      }
      else {
         att = &fb->Attachment[BUFFER_COLOR0 + i];
         test_attachment_completeness(ctx, GL_COLOR, att);
         if (!att->Complete) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT;
            return;
         }
      }

      if (att->Type == GL_TEXTURE) {
         w = att->Texture->Image[att->CubeMapFace][att->TextureLevel]->Width;
         h = att->Texture->Image[att->CubeMapFace][att->TextureLevel]->Height;
         f = att->Texture->Image[att->CubeMapFace][att->TextureLevel]->Format;
         numImages++;
         if (f != GL_RGB && f != GL_RGBA && f != GL_DEPTH_COMPONENT) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT;
            return;
         }
      }
      else if (att->Type == GL_RENDERBUFFER_EXT) {
         w = att->Renderbuffer->Width;
         h = att->Renderbuffer->Height;
         f = att->Renderbuffer->InternalFormat;
         numImages++;
      }
      else {
         assert(att->Type == GL_NONE);
         continue;
      }

      if (numImages == 1) {
         /* set required width, height and format */
         width = w;
         height = h;
         if (i >= 0)
            intFormat = f;
      }
      else {
         /* check that width, height, format are same */
         if (w != width || h != height) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT;
            return;
         }
         if (intFormat != GL_NONE && f != intFormat) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT;
            return;
         }
      }
   }

   /* Check that all DrawBuffers are present */
   for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
      if (fb->ColorDrawBuffer[i] != GL_NONE) {
         const struct gl_renderbuffer_attachment *att
            = get_attachment(ctx, fb, fb->ColorDrawBuffer[i]);
         assert(att);
         if (att->Type == GL_NONE) {
            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT;
            return;
         }
      }
   }

   /* Check that the ReadBuffer is present */
   if (fb->ColorReadBuffer != GL_NONE) {
      const struct gl_renderbuffer_attachment *att
         = get_attachment(ctx, fb, fb->ColorReadBuffer);
      assert(att);
      if (att->Type == GL_NONE) {
         fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT;
         return;
      }
   }

   /* Check if any renderbuffer is attached more than once */
   for (i = 0; i < BUFFER_COUNT - 1; i++) {