LibGL+LibGPU+LibSoftGPU: Implement flexible pixel format conversion

A GPU (driver) is now responsible for reading and writing pixels from
and to user data. The client (LibGL) is responsible for specifying how
the user data must be interpreted or written to.

This allows us to centralize all pixel format conversion in one class,
`LibSoftGPU::PixelConverter`. For both the input and output image, it
takes a specification containing the image dimensions, the pixel type
and the selection (basically a clipping rect), and converts the pixels
from the input image to the output image.

Effectively this means we now support almost all OpenGL 1.5 formats,
and all custom logic has disappeared from:
  - `glDrawPixels`
  - `glReadPixels`
  - `glTexImage2D`
  - `glTexSubImage2D`

The new logic is still unoptimized, but on my machine I experienced no
noticeable slowdown. :^)

1 files changed, 20 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGL/Image.h b/Userland/Libraries/LibGL/Image.h
new file mode 100644
index 0000000000..aed64d30c0
--- /dev/null
+++ b/Userland/Libraries/LibGL/Image.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2022, Jelle Raaijmakers <jelle@gmta.nl>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Error.h>
+#include <LibGL/GL/gl.h>
+#include <LibGL/GLContext.h>
+#include <LibGPU/ImageDataLayout.h>
+#include <LibGPU/ImageFormat.h>
+
+namespace GL {
+
+GPU::PixelType get_format_specification(GLenum format, GLenum type);
+ErrorOr<GPU::PixelType> get_validated_pixel_type(GLenum target, GLenum internal_format, GLenum format, GLenum type);
+
+}