mesa: add missing color buffer datatype check for glBlitFramebuffer()

Reviewed-By: Jose Fonseca <jfonseca@vmware.com>

src/mesa/main/fbobject.c

@@ -2579,6 +2579,44 @@ find_attachment(const struct gl_framebuffer *fb,
 }
 
 
+/**
+ * Helper function for checking if the datatypes of color buffers are
+ * compatible for glBlitFramebuffer.  From the 3.1 spec, page 198:
+ *
+ * "GL_INVALID_OPERATION is generated if mask contains GL_COLOR_BUFFER_BIT
+ *  and any of the following conditions hold:
+ *   - The read buffer contains fixed-point or floating-point values and any
+ *     draw buffer contains neither fixed-point nor floating-point values.
+ *   - The read buffer contains unsigned integer values and any draw buffer
+ *     does not contain unsigned integer values.
+ *   - The read buffer contains signed integer values and any draw buffer
+ *     does not contain signed integer values."
+ */
+static GLboolean
+compatible_color_datatypes(gl_format srcFormat, gl_format dstFormat)
+{
+   GLenum srcType = _mesa_get_format_datatype(srcFormat);
+   GLenum dstType = _mesa_get_format_datatype(dstFormat);
+
+   if (srcType != GL_INT && srcType != GL_UNSIGNED_INT) {
+      assert(srcType == GL_UNSIGNED_NORMALIZED ||
+             srcType == GL_SIGNED_NORMALIZED ||
+             srcType == GL_FLOAT);
+      /* Boil any of those types down to GL_FLOAT */
+      srcType = GL_FLOAT;
+   }
+
+   if (dstType != GL_INT && dstType != GL_UNSIGNED_INT) {
+      assert(dstType == GL_UNSIGNED_NORMALIZED ||
+             dstType == GL_SIGNED_NORMALIZED ||
+             dstType == GL_FLOAT);
+      /* Boil any of those types down to GL_FLOAT */
+      dstType = GL_FLOAT;
+   }
+
+   return srcType == dstType;
+}
+
 
 /**
  * Blit rectangular region, optionally from one framebuffer to another.
@@ -2663,6 +2701,12 @@ _mesa_BlitFramebufferEXT(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
 	 colorReadRb = colorDrawRb = NULL;
 	 mask &= ~GL_COLOR_BUFFER_BIT;
       }
+      else if (!compatible_color_datatypes(colorReadRb->Format,
+                                           colorDrawRb->Format)) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "glBlitFramebufferEXT(color buffer datatypes mismatch)");
+         return;
+      }
    }
    else {
       colorReadRb = colorDrawRb = NULL;