godot/thirdparty/libktx/lib/checkheader.c

300 lines
8.1 KiB
C

/* -*- tab-width: 4; -*- */
/* vi: set sw=2 ts=4 expandtab: */
/* $Id$ */
/*
* Copyright 2010-2020 The Khronos Group Inc.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @internal
* @file checkheader.c
* @~English
*
* @brief Function to verify a KTX file header
*
* @author Mark Callow, HI Corporation
*/
/*
* Author: Georg Kolling, Imagination Technology with modifications
* by Mark Callow, HI Corporation.
*/
#include <assert.h>
#include <string.h>
#include "ktx.h"
#include "ktxint.h"
#include "vkformat_enum.h"
bool isProhibitedFormat(VkFormat format);
bool isValidFormat(VkFormat format);
/**
* @internal
* @~English
* @brief Check a KTX file header.
*
* As well as checking that the header identifies a KTX file, the function
* sanity checks the values and returns information about the texture in a
* struct KTX_supplementary_info.
*
* @param pHeader pointer to the KTX header to check
* @param pSuppInfo pointer to a KTX_supplementary_info structure in which to
* return information about the texture.
*
* @author Georg Kolling, Imagination Technology
* @author Mark Callow, HI Corporation
*/
KTX_error_code ktxCheckHeader1_(KTX_header* pHeader,
KTX_supplemental_info* pSuppInfo)
{
ktx_uint8_t identifier_reference[12] = KTX_IDENTIFIER_REF;
ktx_uint32_t max_dim;
assert(pHeader != NULL && pSuppInfo != NULL);
/* Compare identifier, is this a KTX file? */
if (memcmp(pHeader->identifier, identifier_reference, 12) != 0)
{
return KTX_UNKNOWN_FILE_FORMAT;
}
if (pHeader->endianness == KTX_ENDIAN_REF_REV)
{
/* Convert endianness of pHeader fields. */
_ktxSwapEndian32(&pHeader->glType, 12);
if (pHeader->glTypeSize != 1 &&
pHeader->glTypeSize != 2 &&
pHeader->glTypeSize != 4)
{
/* Only 8-, 16-, and 32-bit types supported so far. */
return KTX_FILE_DATA_ERROR;
}
}
else if (pHeader->endianness != KTX_ENDIAN_REF)
{
return KTX_FILE_DATA_ERROR;
}
/* Check glType and glFormat */
pSuppInfo->compressed = 0;
if (pHeader->glType == 0 || pHeader->glFormat == 0)
{
if (pHeader->glType + pHeader->glFormat != 0)
{
/* either both or none of glType, glFormat must be zero */
return KTX_FILE_DATA_ERROR;
}
pSuppInfo->compressed = 1;
}
if (pHeader->glFormat == pHeader->glInternalformat) {
// glInternalFormat is either unsized (which is no longer and should
// never have been supported by libktx) or glFormat is sized.
return KTX_FILE_DATA_ERROR;
}
/* Check texture dimensions. KTX files can store 8 types of textures:
1D, 2D, 3D, cube, and array variants of these. There is currently
no GL extension for 3D array textures. */
if ((pHeader->pixelWidth == 0) ||
(pHeader->pixelDepth > 0 && pHeader->pixelHeight == 0))
{
/* texture must have width */
/* texture must have height if it has depth */
return KTX_FILE_DATA_ERROR;
}
if (pHeader->pixelDepth > 0)
{
if (pHeader->numberOfArrayElements > 0)
{
/* No 3D array textures yet. */
return KTX_UNSUPPORTED_FEATURE;
}
pSuppInfo->textureDimension = 3;
}
else if (pHeader->pixelHeight > 0)
{
pSuppInfo->textureDimension = 2;
}
else
{
pSuppInfo->textureDimension = 1;
}
if (pHeader->numberOfFaces == 6)
{
if (pSuppInfo->textureDimension != 2)
{
/* cube map needs 2D faces */
return KTX_FILE_DATA_ERROR;
}
}
else if (pHeader->numberOfFaces != 1)
{
/* numberOfFaces must be either 1 or 6 */
return KTX_FILE_DATA_ERROR;
}
/* Check number of mipmap levels */
if (pHeader->numberOfMipLevels == 0)
{
pSuppInfo->generateMipmaps = 1;
pHeader->numberOfMipLevels = 1;
}
else
{
pSuppInfo->generateMipmaps = 0;
}
/* This test works for arrays too because height or depth will be 0. */
max_dim = MAX(MAX(pHeader->pixelWidth, pHeader->pixelHeight), pHeader->pixelDepth);
if (max_dim < ((ktx_uint32_t)1 << (pHeader->numberOfMipLevels - 1)))
{
/* Can't have more mip levels than 1 + log2(max(width, height, depth)) */
return KTX_FILE_DATA_ERROR;
}
return KTX_SUCCESS;
}
/**
* @internal
* @~English
* @brief Check a KTX2 file header.
*
* As well as checking that the header identifies a KTX 2 file, the function
* sanity checks the values and returns information about the texture in a
* struct KTX_supplementary_info.
*
* @param pHeader pointer to the KTX header to check
* @param pSuppInfo pointer to a KTX_supplementary_info structure in which to
* return information about the texture.
*
* @author Mark Callow, HI Corporation
*/
KTX_error_code ktxCheckHeader2_(KTX_header2* pHeader,
KTX_supplemental_info* pSuppInfo)
{
// supp info is compressed, generateMipmaps and num dimensions. Don't need
// compressed as formatSize gives us that. I think the other 2 aren't needed.
ktx_uint8_t identifier_reference[12] = KTX2_IDENTIFIER_REF;
assert(pHeader != NULL && pSuppInfo != NULL);
ktx_uint32_t max_dim;
/* Compare identifier, is this a KTX file? */
if (memcmp(pHeader->identifier, identifier_reference, 12) != 0)
{
return KTX_UNKNOWN_FILE_FORMAT;
}
/* Check format */
if (isProhibitedFormat(pHeader->vkFormat))
{
return KTX_FILE_DATA_ERROR;
}
if (!isValidFormat(pHeader->vkFormat))
{
return KTX_UNSUPPORTED_FEATURE;
}
if (pHeader->supercompressionScheme == KTX_SS_BASIS_LZ && pHeader->vkFormat != VK_FORMAT_UNDEFINED)
{
return KTX_FILE_DATA_ERROR;
}
/* Check texture dimensions. KTX files can store 8 types of textures:
1D, 2D, 3D, cube, and array variants of these. There is currently
no extension for 3D array textures in any 3D API. */
if ((pHeader->pixelWidth == 0) ||
(pHeader->pixelDepth > 0 && pHeader->pixelHeight == 0))
{
/* texture must have width */
/* texture must have height if it has depth */
return KTX_FILE_DATA_ERROR;
}
if (pHeader->pixelDepth > 0)
{
if (pHeader->layerCount > 0)
{
/* No 3D array textures yet. */
return KTX_UNSUPPORTED_FEATURE;
}
pSuppInfo->textureDimension = 3;
}
else if (pHeader->pixelHeight > 0)
{
pSuppInfo->textureDimension = 2;
}
else
{
pSuppInfo->textureDimension = 1;
}
if (pHeader->faceCount == 6)
{
if (pSuppInfo->textureDimension != 2)
{
/* cube map needs 2D faces */
return KTX_FILE_DATA_ERROR;
}
if (pHeader->pixelDepth != 0)
{
/* cube map cannot have depth */
return KTX_FILE_DATA_ERROR;
}
if (pHeader->pixelWidth != pHeader->pixelHeight)
{
/* cube map needs square faces */
return KTX_FILE_DATA_ERROR;
}
}
else if (pHeader->faceCount != 1)
{
/* numberOfFaces must be either 1 or 6 */
return KTX_FILE_DATA_ERROR;
}
// Check number of mipmap levels
if (pHeader->levelCount == 0)
{
pSuppInfo->generateMipmaps = 1;
pHeader->levelCount = 1;
}
else
{
pSuppInfo->generateMipmaps = 0;
}
// Check supercompression
switch (pHeader->supercompressionScheme) {
case KTX_SS_NONE:
case KTX_SS_BASIS_LZ:
case KTX_SS_ZSTD:
case KTX_SS_ZLIB:
break;
default:
// Unsupported supercompression
return KTX_UNSUPPORTED_FEATURE;
}
// This test works for arrays too because height or depth will be 0.
max_dim = MAX(MAX(pHeader->pixelWidth, pHeader->pixelHeight), pHeader->pixelDepth);
if (max_dim < ((ktx_uint32_t)1 << (pHeader->levelCount - 1)))
{
// Can't have more mip levels than 1 + log2(max(width, height, depth))
return KTX_FILE_DATA_ERROR;
}
return KTX_SUCCESS;
}