mesa: added _mesa_dump_image() for debugging

src/mesa/main/debug.c

@@ -251,6 +251,9 @@ write_ppm(const char *filename, const GLubyte *buffer, int width, int height,
       }
       fclose(f);
    }
+   else {
+      fprintf(stderr, "Unable to create %s in write_ppm()\n", filename);
+   }
 }
 
 
@@ -549,6 +552,27 @@ _mesa_dump_stencil_buffer(const char *filename)
 }
 
 
+void
+_mesa_dump_image(const char *filename, const void *image, GLuint w, GLuint h,
+                 GLenum format, GLenum type)
+{
+   GLboolean invert = GL_TRUE;
+
+   if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) {
+      write_ppm(filename, image, w, h, 4, 0, 1, 2, invert);
+   }
+   else if (format == GL_BGRA && type == GL_UNSIGNED_BYTE) {
+      write_ppm(filename, image, w, h, 4, 2, 1, 0, invert);
+   }
+   else if (format == GL_LUMINANCE_ALPHA && type == GL_UNSIGNED_BYTE) {
+      write_ppm(filename, image, w, h, 2, 1, 0, 0, invert);
+   }
+   else {
+      _mesa_problem(NULL, "Unsupported format/type in _mesa_dump_image()");
+   }
+}
+
+
 /**
  * Quick and dirty function to "print" a texture to stdout.
  */

src/mesa/main/debug.h

@@ -84,6 +84,10 @@ _mesa_dump_depth_buffer(const char *filename);
 extern void
 _mesa_dump_stencil_buffer(const char *filename);
 
+extern void
+_mesa_dump_image(const char *filename, const void *image, GLuint w, GLuint h,
+                 GLenum format, GLenum type);
+
 extern void
 _mesa_print_texture(struct gl_context *ctx, const struct gl_texture_image *img);