drawpix.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

   }

   if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT ||
       ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
                  "glCopyPixels(incomplete framebuffer)" );
      return;
   }

   if (!_mesa_source_buffer_exists(ctx, type) ||
       !_mesa_dest_buffer_exists(ctx, type)) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCopyPixels(missing source or dest buffer)");
      return;
   }

   if (!ctx->Current.RasterPosValid) {
      return;
   }

   if (ctx->RenderMode == GL_RENDER) {
      /* Round to satisfy conformance tests (matches SGI's OpenGL) */
      GLint destx = IROUND(ctx->Current.RasterPos[0]);
      GLint desty = IROUND(ctx->Current.RasterPos[1]);
      ctx->Driver.CopyPixels( ctx, srcx, srcy, width, height, destx, desty,
			      type );
   }
   else if (ctx->RenderMode == GL_FEEDBACK) {
      FLUSH_CURRENT( ctx, 0 );
      FEEDBACK_TOKEN( ctx, (GLfloat) (GLint) GL_COPY_PIXEL_TOKEN );
      _mesa_feedback_vertex( ctx, 
                             ctx->Current.RasterPos,
                             ctx->Current.RasterColor,
                             ctx->Current.RasterIndex,
                             ctx->Current.RasterTexCoords[0] );
   }
   else {
      ASSERT(ctx->RenderMode == GL_SELECT);
      /* Do nothing.  See OpenGL Spec, Appendix B, Corollary 6. */
   }
}

#endif /* _HAVE_FULL_GL */



void GLAPIENTRY
_mesa_ReadPixels( GLint x, GLint y, GLsizei width, GLsizei height,
		  GLenum format, GLenum type, GLvoid *pixels )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (width < 0 || height < 0) {
      _mesa_error( ctx, GL_INVALID_VALUE,
                   "glReadPixels(width=%d height=%d)", width, height );
      return;
   }

   if (ctx->NewState)
      _mesa_update_state(ctx);

   if (error_check_format_type(ctx, format, type, GL_FALSE)) {
      /* found an error */
      return;
   }

   if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
                  "glReadPixels(incomplete framebuffer)" );
      return;
   }

   if (!_mesa_source_buffer_exists(ctx, format)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(no readbuffer)");
      return;
   }

   if (ctx->Pack.BufferObj->Name) {
      if (!_mesa_validate_pbo_access(2, &ctx->Pack, width, height, 1,
                                     format, type, pixels)) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glReadPixels(invalid PBO access)");
         return;
      }

      if (ctx->Pack.BufferObj->Pointer) {
         /* buffer is mapped - that's an error */
         _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
         return;
      }
   }

   ctx->Driver.ReadPixels(ctx, x, y, width, height,
			  format, type, &ctx->Pack, pixels);
}



void GLAPIENTRY
_mesa_Bitmap( GLsizei width, GLsizei height,
              GLfloat xorig, GLfloat yorig, GLfloat xmove, GLfloat ymove,
              const GLubyte *bitmap )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (width < 0 || height < 0) {
      _mesa_error( ctx, GL_INVALID_VALUE, "glBitmap(width or height < 0)" );
      return;
   }

   if (!ctx->Current.RasterPosValid) {
      return;    /* do nothing */
   }

   if (ctx->NewState) {
      _mesa_update_state(ctx);
   }

   if (ctx->FragmentProgram.Enabled && !ctx->FragmentProgram._Enabled) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glBitmap (invalid fragment program)");
      return;
   }

   if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
                  "glBitmap(incomplete framebuffer)");
      return;
   }

   if (ctx->RenderMode == GL_RENDER) {
      /* Truncate, to satisfy conformance tests (matches SGI's OpenGL). */
      const GLfloat epsilon = 0.0001;
      GLint x = IFLOOR(ctx->Current.RasterPos[0] + epsilon - xorig);
      GLint y = IFLOOR(ctx->Current.RasterPos[1] + epsilon - yorig);

      if (ctx->Unpack.BufferObj->Name) {
         /* unpack from PBO */
         if (!_mesa_validate_pbo_access(2, &ctx->Unpack, width, height, 1,
                                        GL_COLOR_INDEX, GL_BITMAP,
                                        (GLvoid *) bitmap)) {
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glBitmap(invalid PBO access)");
            return;
         }
         if (ctx->Unpack.BufferObj->Pointer) {
            /* buffer is mapped - that's an error */
            _mesa_error(ctx, GL_INVALID_OPERATION, "glBitmap(PBO is mapped)");
            return;
         }
      }

      ctx->Driver.Bitmap( ctx, x, y, width, height, &ctx->Unpack, bitmap );
   }
#if _HAVE_FULL_GL
   else if (ctx->RenderMode == GL_FEEDBACK) {
      FLUSH_CURRENT(ctx, 0);
      FEEDBACK_TOKEN( ctx, (GLfloat) (GLint) GL_BITMAP_TOKEN );
      _mesa_feedback_vertex( ctx,
                             ctx->Current.RasterPos,
                             ctx->Current.RasterColor,
                             ctx->Current.RasterIndex, 
                             ctx->Current.RasterTexCoords[0] );
   }
   else {
      ASSERT(ctx->RenderMode == GL_SELECT);
      /* Do nothing.  See OpenGL Spec, Appendix B, Corollary 6. */
   }
#endif

   /* update raster position */
   ctx->Current.RasterPos[0] += xmove;
   ctx->Current.RasterPos[1] += ymove;
}



#if 0  /* experimental */
/*
 * Execute glDrawDepthPixelsMESA().  This function accepts both a color
 * image and depth (Z) image.  Rasterization produces fragments with
 * color and Z taken from these images.  This function is intended for
 * Z-compositing.  Normally, this operation requires two glDrawPixels
 * calls with stencil testing.
 */
void GLAPIENTRY
_mesa_DrawDepthPixelsMESA( GLsizei width, GLsizei height,
                           GLenum colorFormat, GLenum colorType,
                           const GLvoid *colors,
                           GLenum depthType, const GLvoid *depths )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (width < 0 || height < 0) {
      _mesa_error( ctx, GL_INVALID_VALUE,
                   "glDrawDepthPixelsMESA(width or height < 0" );
      return;
   }

   if (!ctx->Current.RasterPosValid) {
      return;
   }

   if (ctx->NewState) {
      _mesa_update_state(ctx);
   }

   if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
                  "glDrawDepthPixelsMESA(incomplete framebuffer)");
      return;
   }

   if (ctx->RenderMode == GL_RENDER) {
      /* Round, to satisfy conformance tests (matches SGI's OpenGL) */
      GLint x = IROUND(ctx->Current.RasterPos[0]);
      GLint y = IROUND(ctx->Current.RasterPos[1]);
      ctx->Driver.DrawDepthPixelsMESA(ctx, x, y, width, height,
                                      colorFormat, colorType, colors,
                                      depthType, depths, &ctx->Unpack);
   }
   else if (ctx->RenderMode == GL_FEEDBACK) {
      /* Feedback the current raster pos info */
      FLUSH_CURRENT( ctx, 0 );
      FEEDBACK_TOKEN( ctx, (GLfloat) (GLint) GL_DRAW_PIXEL_TOKEN );
      _mesa_feedback_vertex( ctx,
                             ctx->Current.RasterPos,
                             ctx->Current.RasterColor,
                             ctx->Current.RasterIndex,
                             ctx->Current.RasterTexCoords[0] );
   }
   else {
      ASSERT(ctx->RenderMode == GL_SELECT);
      /* Do nothing.  See OpenGL Spec, Appendix B, Corollary 6. */
   }
}

#endif