Files
enduro2d/sources/enduro2d/utils/image_impl/image_reader_pvr.cpp

239 lines
7.0 KiB
C++

/*******************************************************************************
* This file is part of the "Enduro2D"
* For conditions of distribution and use, see copyright notice in LICENSE.md
* Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
******************************************************************************/
#include "image_impl.hpp"
namespace
{
// PVR format specification:
// https://cdn.imgtec.com/sdk-documentation/PVR+File+Format.Specification.pdf
using namespace e2d;
enum class pvr_flags : u32 {
none = 0,
premultiplied = 0x02,
};
enum class pvr_pixel_format : u64 {
pvrtc_2bpp_rgb = 0,
pvrtc_2bpp_rgba = 1,
pvrtc_4bpp_rgb = 2,
pvrtc_4bpp_rgba = 3,
pvrtc_ii_2bpp = 4,
pvrtc_ii_4bpp = 5,
etc1 = 6,
dxt1 = 7,
dxt2 = 8,
dxt3 = 9,
dxt4 = 10,
dxt5 = 11,
bc1 = 7,
bc2 = 9,
bc3 = 11,
bc4 = 12,
bc5 = 13,
bc6 = 14,
bc7 = 15,
uyvy = 16,
yuy2 = 17,
bw_1bpp = 18,
r9g9b9e5 = 19,
rgbg8888 = 20,
grgb8888 = 21,
etc2_rgb = 22,
etc2_rgba = 23,
etc2_rgb_a1 = 24,
eac_r11 = 25,
eac_rg11 = 26,
astc_4x4 = 27,
astc_5x4 = 28,
astc_5x5 = 29,
astc_6x5 = 30,
astc_6x6 = 31,
astc_8x5 = 32,
astc_8x6 = 33,
astc_8x8 = 34,
astc_10x5 = 35,
astc_10x6 = 36,
astc_10x8 = 37,
astc_10x10 = 38,
astc_12x10 = 39,
astc_12x12 = 40,
rgba8 = 0x08080808'61626772ull,
r8 = 0x00000008'00000072ull,
rg8 = 0x00000808'00006772ull,
rgb8 = 0x00080808'00626772ull,
};
enum class pvr_color_space : u32 {
linear = 0,
srgb = 1,
};
enum class pvr_channel_type : u32 {
byte_unorm = 0,
byte_snorm = 1,
ubyte = 2,
sbyte = 3,
short_unorm = 4,
short_snorm = 5,
ushort = 6,
sshort = 7,
int_unorm = 8,
int_snorm = 9,
uint = 10,
sint = 11,
sfloat = 12,
};
struct pvr_header {
u32 version;
u32 flags;
u32 pixelFormat0;
u32 pixelFormat1;
u32 colorSpace;
u32 channelType;
u32 height;
u32 width;
u32 depth;
u32 numSurfaces;
u32 numFaces;
u32 mipMapCount;
u32 metaDataSize;
};
static_assert(sizeof(pvr_header) == 52, "invalid PVR header size");
bool is_pvr(const void* data, std::size_t byte_size) noexcept {
if ( byte_size > sizeof(pvr_header) ) {
const pvr_header* hdr = reinterpret_cast<const pvr_header*>(data);
return hdr->version == 0x03525650;
}
return false;
}
bool get_pvr_format(
const pvr_header& hdr,
image_data_format& out_format,
u32& out_bytes_per_block,
v2u& out_block_size) noexcept
{
if ( pvr_color_space(hdr.colorSpace) != pvr_color_space::linear ) {
return false;
}
const pvr_pixel_format fmt = pvr_pixel_format(
hdr.pixelFormat0 | (u64(hdr.pixelFormat1) << 32));
switch (fmt)
{
case pvr_pixel_format::pvrtc_2bpp_rgb:
out_format = image_data_format::rgb_pvrtc2;
out_bytes_per_block = 8;
out_block_size = v2u(8,4);
break;
case pvr_pixel_format::pvrtc_2bpp_rgba:
out_format = image_data_format::rgba_pvrtc2;
out_bytes_per_block = 8;
out_block_size = v2u(8,4);
break;
case pvr_pixel_format::pvrtc_4bpp_rgb:
out_format = image_data_format::rgb_pvrtc4;
out_bytes_per_block = 8;
out_block_size = v2u(4,4);
break;
case pvr_pixel_format::pvrtc_4bpp_rgba:
out_format = image_data_format::rgba_pvrtc4;
out_bytes_per_block = 8;
out_block_size = v2u(4,4);
break;
case pvr_pixel_format::pvrtc_ii_2bpp:
out_format = image_data_format::rgba_pvrtc2_v2;
out_bytes_per_block = 8;
out_block_size = v2u(8,4);
break;
case pvr_pixel_format::pvrtc_ii_4bpp:
out_format = image_data_format::rgba_pvrtc4_v2;
out_bytes_per_block = 8;
out_block_size = v2u(4,4);
break;
case pvr_pixel_format::dxt1:
out_format = image_data_format::rgb_dxt1;
out_bytes_per_block = 8;
out_block_size = v2u(4,4);
break;
case pvr_pixel_format::dxt3:
out_format = image_data_format::rgba_dxt3;
out_bytes_per_block = 16;
out_block_size = v2u(4,4);
break;
case pvr_pixel_format::dxt5:
out_format = image_data_format::rgba_dxt5;
out_bytes_per_block = 16;
out_block_size = v2u(4,4);
break;
case pvr_pixel_format::rgba8:
out_format = image_data_format::rgba8;
out_bytes_per_block = 4;
out_block_size = v2u(1,1);
break;
case pvr_pixel_format::r8:
out_format = image_data_format::g8;
out_bytes_per_block = 1;
out_block_size = v2u(1,1);
break;
case pvr_pixel_format::rg8:
out_format = image_data_format::ga8;
out_bytes_per_block = 2;
out_block_size = v2u(1,1);
break;
case pvr_pixel_format::rgb8:
out_format = image_data_format::rgb8;
out_bytes_per_block = 3;
out_block_size = v2u(1,1);
break;
default:
return false;
}
return true;
}
}
namespace e2d::images::impl
{
bool load_image_pvr(image& dst, const buffer& src) {
if ( !is_pvr(src.data(), src.size()) ) {
return false;
}
const pvr_header& hdr = *reinterpret_cast<const pvr_header*>(src.data());
const u8* content = src.data() + sizeof(pvr_header) + hdr.metaDataSize;
const std::size_t content_size = static_cast<std::size_t>(src.data() + src.size() - content);
if ( hdr.numSurfaces != 1 || hdr.numFaces != 1 || hdr.depth > 1 ) {
return false; // cubemap and volume textures are not supported
}
image_data_format format = image_data_format(-1);
u32 bytes_per_block = 0;
v2u block_size = v2u(1,1);
if ( !get_pvr_format(hdr, format, bytes_per_block, block_size) ) {
return false;
}
const v2u dimension = v2u(hdr.width, hdr.height);
const std::size_t size = bytes_per_block *
((dimension.x + block_size.x - 1) / block_size.x) *
((dimension.y + block_size.y - 1) / block_size.y);
if ( content_size != size ) {
return false;
}
dst = image(dimension, format, buffer(content, size));
return true;
}
}