vk2gl.c

/* -*- tab-width: 4; -*- */
/* vi: set sw=2 ts=4 expandtab textwidth=70: */

/*
 * Copyright 2024 Mark Callow.
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @internal
 * @file vk2gl.h
 * @~English
 *
 * @brief Test compilation of GL format mappings.
 *
 * Note that this requires a @c vulkan_core.h with a VkFormat that includes
 * the ASTC 3D formats which are not currently in the standard
 * @c vulkan_core.h. A suitable file can be found at
 *
 * https://github.com/KhronosGroup/dfdutils/blob/main/vulkan/vulkan_core.h
 *
 * Once these formats are included in the standard @c vulkan_core.h
 * the above file will be removed.
 *
 * Tokens used in the case statements and results can be found in
 * @c vulkan_core.h version 267+ (except ASTC 3D tokens),
 * a @c glcorearb.h circa early 2024 (glcorearb.h has no version
 * number) or defined below.
 */

#include "vulkan/vulkan_core.h"
#include "GL/glcorearb.h"

// These are only in glext.h.

#if !defined( GL_COMPRESSED_SRGB_S3TC_DXT1_EXT )
#define GL_COMPRESSED_SRGB_S3TC_DXT1_EXT                0x8C4C
#endif
#if !defined( GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT )
#define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT          0x8C4D
#endif
#if !defined( GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT )
#define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT          0x8C4E
#endif
#if !defined( GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT )
#define GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT          0x8C4F
#endif

// These are only in GLES headers not in glcorearb.h or glext.h.

//
// ETC
//

#if !defined( GL_ETC1_RGB8_OES )
#define GL_ETC1_RGB8_OES                                0x8D64
#endif

//
// PVRTC
//

#if !defined( GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG )
#define GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG              0x8C01
#define GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG              0x8C00
#define GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG             0x8C03
#define GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG             0x8C02
#endif
#if !defined( GL_COMPRESSED_RGBA_PVRTC_2BPPV2_IMG )
#define GL_COMPRESSED_RGBA_PVRTC_2BPPV2_IMG             0x9137
#define GL_COMPRESSED_RGBA_PVRTC_4BPPV2_IMG             0x9138
#endif
#if !defined( GL_COMPRESSED_SRGB_PVRTC_2BPPV1_EXT )
#define GL_COMPRESSED_SRGB_PVRTC_2BPPV1_EXT             0x8A54
#define GL_COMPRESSED_SRGB_PVRTC_4BPPV1_EXT             0x8A55
#define GL_COMPRESSED_SRGB_ALPHA_PVRTC_2BPPV1_EXT       0x8A56
#define GL_COMPRESSED_SRGB_ALPHA_PVRTC_4BPPV1_EXT       0x8A57
#endif
#if !defined( GL_COMPRESSED_SRGB_ALPHA_PVRTC_2BPPV2_IMG )
#define GL_COMPRESSED_SRGB_ALPHA_PVRTC_2BPPV2_IMG       0x93F0
#define GL_COMPRESSED_SRGB_ALPHA_PVRTC_4BPPV2_IMG       0x93F1
#endif

//
// ASTC
//

#if !defined( GL_COMPRESSED_RGBA_ASTC_3x3x3_OES )
#define GL_COMPRESSED_RGBA_ASTC_3x3x3_OES               0x93C0
#define GL_COMPRESSED_RGBA_ASTC_4x3x3_OES               0x93C1
#define GL_COMPRESSED_RGBA_ASTC_4x4x3_OES               0x93C2
#define GL_COMPRESSED_RGBA_ASTC_4x4x4_OES               0x93C3
#define GL_COMPRESSED_RGBA_ASTC_5x4x4_OES               0x93C4
#define GL_COMPRESSED_RGBA_ASTC_5x5x4_OES               0x93C5
#define GL_COMPRESSED_RGBA_ASTC_5x5x5_OES               0x93C6
#define GL_COMPRESSED_RGBA_ASTC_6x5x5_OES               0x93C7
#define GL_COMPRESSED_RGBA_ASTC_6x6x5_OES               0x93C8
#define GL_COMPRESSED_RGBA_ASTC_6x6x6_OES               0x93C9
#endif

#if !defined( GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES )
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES       0x93E0
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES       0x93E1
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES       0x93E2
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES       0x93E3
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES       0x93E4
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES       0x93E5
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES       0x93E6
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES       0x93E7
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES       0x93E8
#define GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES       0x93E9
#endif


/**
 * @brief Return the glInternalFormat equivalent to the vkFormat.
 *
 * @param[in] vkFormat VkFormat enumerator value to look up.
 *
 * @return a GLenum with the equivalent internal format value.
 *         GL_INVALID_VALUE if none found.
 */
GLenum vkFormat2glInternalFormat( VkFormat vkFormat )
{
    switch ( vkFormat )
    {
#include "vkFormat2glInternalFormat.inl"
        default: return GL_INVALID_VALUE;
    }
}


/**
 * @brief Return the glFormat equivalent to the vkFormat.
 *
 * Only non-block compressed vkFormats have an equivalent glFormat as
 * only the glInternalformat is needed for loading compressed
 * textures. GL_INVALID_VALUE is returned for block-compressed formats.
 *
 * It is not possible to tell from the vkFormat token value when the
 * format is block compressed. If operating in the context of a KTX
 * file the embedded DFD's @c colorModel can be used to distinguish.
 *
 * @param[in] vkFormat VkFormat enumerator value to look up.
 *
 * @return a GLenum with the equivalent format value. GL_INVALID_VALUE
 *         if none found.
 */
GLenum vkFormat2glFormat( VkFormat vkFormat )
{
    switch ( vkFormat )
    {
#include "vkFormat2glFormat.inl"
        default: return GL_INVALID_VALUE;
    }
}


/**
 * @brief Return the glType equivalent to the vkFormat.
 *
 * Only non-block compressed vkFormats have an equivalent glType as
 * only the glInternalformat is needed for loading compressed
 * textures. @see vkFormat2glFormat for more details.
 *
 * @param[in] vkFormat VkFormat enumerator value to look up.
 *
 * @return a GLenum with the equivalent format value. GL_INVALID_VALUE
 *         if none found.
 */
GLenum vkFormat2glType( VkFormat vkFormat )
{
    switch ( vkFormat )
    {
#include "vkFormat2glType.inl"
        default: return GL_INVALID_VALUE;
    }
}