Add support for KTX & KTX2 image format

Add support glTF KHR_texture_basisu extension

1 files changed, 266 insertions, 0 deletions

diff --git a/thirdparty/libktx/lib/ktxint.h b/thirdparty/libktx/lib/ktxint.h
new file mode 100644
index 0000000000..03c9945ce7
--- /dev/null
+++ b/thirdparty/libktx/lib/ktxint.h
@@ -0,0 +1,266 @@
+/* -*- tab-width: 4; -*- */
+/* vi: set sw=2 ts=4 expandtab: */
+
+/* $Id: e36ad79b5eac8ea237d6a05602c71aadab575519 $ */
+
+/*
+ * Copyright 2010-2020 The Khronos Group Inc.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+
+/*
+ * Author: Mark Callow from original code by Georg Kolling
+ */
+
+#ifndef KTXINT_H
+#define KTXINT_H
+
+#include <math.h>
+
+/* Define this to include the ETC unpack software in the library. */
+#ifndef SUPPORT_SOFTWARE_ETC_UNPACK
+  /* Include for all GL versions because have seen OpenGL ES 3
+   * implementaions that do not support ETC1 (ARM Mali emulator v1.0)!
+   */
+  #define SUPPORT_SOFTWARE_ETC_UNPACK 1
+#endif
+
+#ifndef MAX
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#endif
+
+#define QUOTE(x) #x
+#define STR(x) QUOTE(x)
+
+#define KTX2_IDENTIFIER_REF  { 0xAB, 0x4B, 0x54, 0x58, 0x20, 0x32, 0x30, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A }
+#define KTX2_HEADER_SIZE     (80)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @internal
+ * @brief used to pass GL context capabilites to subroutines.
+ */
+#define _KTX_NO_R16_FORMATS     0x0
+#define _KTX_R16_FORMATS_NORM   0x1
+#define _KTX_R16_FORMATS_SNORM  0x2
+#define _KTX_ALL_R16_FORMATS (_KTX_R16_FORMATS_NORM | _KTX_R16_FORMATS_SNORM)
+extern GLint _ktxR16Formats;
+extern GLboolean _ktxSupportsSRGB;
+
+/**
+ * @internal
+ * @~English
+ * @brief KTX file header.
+ *
+ * See the KTX specification for descriptions.
+ */
+typedef struct KTX_header {
+    ktx_uint8_t  identifier[12];
+    ktx_uint32_t endianness;
+    ktx_uint32_t glType;
+    ktx_uint32_t glTypeSize;
+    ktx_uint32_t glFormat;
+    ktx_uint32_t glInternalformat;
+    ktx_uint32_t glBaseInternalformat;
+    ktx_uint32_t pixelWidth;
+    ktx_uint32_t pixelHeight;
+    ktx_uint32_t pixelDepth;
+    ktx_uint32_t numberOfArrayElements;
+    ktx_uint32_t numberOfFaces;
+    ktx_uint32_t numberOfMipLevels;
+    ktx_uint32_t bytesOfKeyValueData;
+} KTX_header;
+
+/* This will cause compilation to fail if the struct size doesn't match */
+typedef int KTX_header_SIZE_ASSERT [sizeof(KTX_header) == KTX_HEADER_SIZE];
+
+/**
+ * @internal
+ * @~English
+ * @brief 32-bit KTX 2 index entry.
+ */
+typedef struct ktxIndexEntry32 {
+    ktx_uint32_t byteOffset; /*!< Offset of item from start of file. */
+    ktx_uint32_t byteLength; /*!< Number of bytes of data in the item. */
+} ktxIndexEntry32;
+/**
+ * @internal
+ * @~English
+ * @brief 64-bit KTX 2 index entry.
+ */
+typedef struct ktxIndexEntry64 {
+    ktx_uint64_t byteOffset; /*!< Offset of item from start of file. */
+    ktx_uint64_t byteLength; /*!< Number of bytes of data in the item. */
+} ktxIndexEntry64;
+
+/**
+ * @internal
+ * @~English
+ * @brief KTX 2 file header.
+ *
+ * See the KTX 2 specification for descriptions.
+ */
+typedef struct KTX_header2 {
+    ktx_uint8_t  identifier[12];
+    ktx_uint32_t vkFormat;
+    ktx_uint32_t typeSize;
+    ktx_uint32_t pixelWidth;
+    ktx_uint32_t pixelHeight;
+    ktx_uint32_t pixelDepth;
+    ktx_uint32_t layerCount;
+    ktx_uint32_t faceCount;
+    ktx_uint32_t levelCount;
+    ktx_uint32_t supercompressionScheme;
+    ktxIndexEntry32 dataFormatDescriptor;
+    ktxIndexEntry32 keyValueData;
+    ktxIndexEntry64 supercompressionGlobalData;
+} KTX_header2;
+
+/* This will cause compilation to fail if the struct size doesn't match */
+typedef int KTX_header2_SIZE_ASSERT [sizeof(KTX_header2) == KTX2_HEADER_SIZE];
+
+/**
+ * @internal
+ * @~English
+ * @brief KTX 2 level index entry.
+ */
+typedef struct ktxLevelIndexEntry {
+    ktx_uint64_t byteOffset; /*!< Offset of level from start of file. */
+    ktx_uint64_t byteLength;
+                /*!< Number of bytes of compressed image data in the level. */
+    ktx_uint64_t uncompressedByteLength;
+                /*!< Number of bytes of uncompressed image data in the level. */
+} ktxLevelIndexEntry;
+
+/**
+ * @internal
+ * @~English
+ * @brief Structure for supplemental information about the texture.
+ *
+ * _ktxCheckHeader returns supplemental information about the texture in this
+ * structure that is derived during checking of the file header.
+ */
+typedef struct KTX_supplemental_info
+{
+    ktx_uint8_t compressed;
+    ktx_uint8_t generateMipmaps;
+    ktx_uint16_t textureDimension;
+} KTX_supplemental_info;
+/**
+ * @internal
+ * @var ktx_uint8_t KTX_supplemental_info::compressed
+ * @~English
+ * @brief KTX_TRUE, if this a compressed texture, KTX_FALSE otherwise?
+ */
+/**
+ * @internal
+ * @var ktx_uint8_t KTX_supplemental_info::generateMipmaps
+ * @~English
+ * @brief KTX_TRUE, if mipmap generation is required, KTX_FALSE otherwise.
+ */
+/**
+ * @internal
+ * @var ktx_uint16_t KTX_supplemental_info::textureDimension
+ * @~English
+ * @brief The number of dimensions, 1, 2 or 3, of data in the texture image.
+ */
+
+/*
+ * @internal
+ * CheckHeader1
+ *
+ * Reads the KTX file header and performs some sanity checking on the values
+ */
+KTX_error_code ktxCheckHeader1_(KTX_header* pHeader,
+                                KTX_supplemental_info* pSuppInfo);
+
+/*
+ * @internal
+ * CheckHeader2
+ *
+ * Reads the KTX 2 file header and performs some sanity checking on the values
+ */
+KTX_error_code ktxCheckHeader2_(KTX_header2* pHeader,
+                                KTX_supplemental_info* pSuppInfo);
+
+/*
+ * SwapEndian16: Swaps endianness in an array of 16-bit values
+ */
+void _ktxSwapEndian16(ktx_uint16_t* pData16, ktx_size_t count);
+
+/*
+ * SwapEndian32: Swaps endianness in an array of 32-bit values
+ */
+void _ktxSwapEndian32(ktx_uint32_t* pData32, ktx_size_t count);
+
+/*
+ * SwapEndian32: Swaps endianness in an array of 64-bit values
+ */
+void _ktxSwapEndian64(ktx_uint64_t* pData64, ktx_size_t count);
+
+/*
+ * UnpackETC: uncompresses an ETC compressed texture image
+ */
+KTX_error_code _ktxUnpackETC(const GLubyte* srcETC, const GLenum srcFormat,
+                             ktx_uint32_t active_width, ktx_uint32_t active_height,
+                             GLubyte** dstImage,
+                             GLenum* format, GLenum* internalFormat, GLenum* type,
+                             GLint R16Formats, GLboolean supportsSRGB);
+
+/*
+ * Pad nbytes to next multiple of n
+ */
+#define _KTX_PADN(n, nbytes) (ktx_uint32_t)(n * ceilf((float)(nbytes) / n))
+/*
+ * Calculate bytes of of padding needed to reach next multiple of n.
+ */
+/* Equivalent to (n * ceil(nbytes / n)) - nbytes */
+#define _KTX_PADN_LEN(n, nbytes) \
+    (ktx_uint32_t)((n * ceilf((float)(nbytes) / n)) - (nbytes))
+
+/*
+ * Pad nbytes to next multiple of 4
+ */
+#define _KTX_PAD4(nbytes) _KTX_PADN(4, nbytes)
+/*
+ * Calculate bytes of of padding needed to reach next multiple of 4.
+ */
+#define _KTX_PAD4_LEN(nbytes) _KTX_PADN_LEN(4, nbytes)
+
+/*
+ * Pad nbytes to next multiple of 8
+ */
+#define _KTX_PAD8(nbytes) _KTX_PADN(8, nbytes)
+/*
+ * Calculate bytes of of padding needed to reach next multiple of 8.
+ */
+#define _KTX_PAD8_LEN(nbytes) _KTX_PADN_LEN(8, nbytes)
+
+/*
+ * Pad nbytes to KTX_GL_UNPACK_ALIGNMENT
+ */
+#define _KTX_PAD_UNPACK_ALIGN(nbytes)  \
+        _KTX_PADN(KTX_GL_UNPACK_ALIGNMENT, nbytes)
+/*
+ * Calculate bytes of of padding needed to reach KTX_GL_UNPACK_ALIGNMENT.
+ */
+#define _KTX_PAD_UNPACK_ALIGN_LEN(nbytes)  \
+        _KTX_PADN_LEN(KTX_GL_UNPACK_ALIGNMENT, nbytes)
+
+/*
+ ======================================
+     Internal utility functions
+ ======================================
+*/
+
+void printKTX2Info2(ktxStream* src, KTX_header2* header);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* KTXINT_H */