minetest/irr/src/CImageLoaderTGA.cpp
2024-03-26 21:39:02 +01:00

247 lines
7.8 KiB
C++

// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#include "CImageLoaderTGA.h"
#include "IReadFile.h"
#include "os.h"
#include "CColorConverter.h"
#include "CImage.h"
#include "irrString.h"
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
namespace irr
{
namespace video
{
//! returns true if the file maybe is able to be loaded by this class
//! based on the file extension (e.g. ".tga")
bool CImageLoaderTGA::isALoadableFileExtension(const io::path &filename) const
{
return core::hasFileExtension(filename, "tga");
}
//! loads a compressed tga.
u8 *CImageLoaderTGA::loadCompressedImage(io::IReadFile *file, const STGAHeader &header) const
{
// This was written and sent in by Jon Pry, thank you very much!
// I only changed the formatting a little bit.
const u32 bytesPerPixel = header.PixelDepth / 8;
const u32 imageSize = header.ImageHeight * header.ImageWidth * bytesPerPixel;
u8 *data = new u8[imageSize];
u32 currentByte = 0;
while (currentByte < imageSize) {
u8 chunkheader = 0;
file->read(&chunkheader, sizeof(u8)); // Read The Chunk's Header
if (chunkheader < 128) { // If The Chunk Is A 'RAW' Chunk
chunkheader++; // Add 1 To The Value To Get Total Number Of Raw Pixels
const u32 bytesToRead = bytesPerPixel * chunkheader;
if (currentByte + bytesToRead <= imageSize) {
file->read(&data[currentByte], bytesToRead);
currentByte += bytesToRead;
} else {
os::Printer::log("Compressed TGA file RAW chunk tries writing beyond buffer", file->getFileName(), ELL_WARNING);
break;
}
} else {
// thnx to neojzs for some fixes with this code
// If It's An RLE Header
chunkheader -= 127; // Subtract 127 To Get Rid Of The ID Bit
u32 dataOffset = currentByte;
if (dataOffset + bytesPerPixel < imageSize) {
file->read(&data[dataOffset], bytesPerPixel);
currentByte += bytesPerPixel;
} else {
os::Printer::log("Compressed TGA file RLE headertries writing beyond buffer", file->getFileName(), ELL_WARNING);
break;
}
for (u32 counter = 1; counter < chunkheader; counter++) {
if (currentByte + bytesPerPixel <= imageSize) {
for (u32 elementCounter = 0; elementCounter < bytesPerPixel; elementCounter++) {
data[currentByte + elementCounter] = data[dataOffset + elementCounter];
}
}
currentByte += bytesPerPixel;
}
}
}
return data;
}
//! returns true if the file maybe is able to be loaded by this class
bool CImageLoaderTGA::isALoadableFileFormat(io::IReadFile *file) const
{
if (!file)
return false;
STGAFooter footer;
memset(&footer, 0, sizeof(STGAFooter));
file->seek(file->getSize() - sizeof(STGAFooter));
file->read(&footer, sizeof(STGAFooter));
return (!strcmp(footer.Signature, "TRUEVISION-XFILE.")); // very old tgas are refused.
}
//! creates a surface from the file
IImage *CImageLoaderTGA::loadImage(io::IReadFile *file) const
{
STGAHeader header;
u32 *palette = 0;
file->read(&header, sizeof(STGAHeader));
#ifdef __BIG_ENDIAN__
header.ColorMapLength = os::Byteswap::byteswap(header.ColorMapLength);
header.ImageWidth = os::Byteswap::byteswap(header.ImageWidth);
header.ImageHeight = os::Byteswap::byteswap(header.ImageHeight);
#endif
if (!checkImageDimensions(header.ImageWidth, header.ImageHeight)) {
os::Printer::log("Image dimensions too large in file", file->getFileName(), ELL_ERROR);
return 0;
}
// skip image identification field
if (header.IdLength)
file->seek(header.IdLength, true);
if (header.ColorMapType) {
// Create 32 bit palette
// `core::max_()` is not used here because it takes its inputs as references. Since `header` is packed, use the macro `MAX()` instead:
const irr::u16 paletteSize = MAX((u16)256u, header.ColorMapLength); // ColorMapLength can lie, but so far we only use palette for 8-bit, so ensure it has 256 entries
palette = new u32[paletteSize];
if (paletteSize > header.ColorMapLength) {
// To catch images using palette colors with invalid indices
const irr::u32 errorCol = irr::video::SColor(255, 255, 0, 205).color; // bright magenta
for (irr::u16 i = header.ColorMapLength; i < paletteSize; ++i)
palette[i] = errorCol;
}
// read color map
u8 *colorMap = new u8[header.ColorMapEntrySize / 8 * header.ColorMapLength];
file->read(colorMap, header.ColorMapEntrySize / 8 * header.ColorMapLength);
// convert to 32-bit palette
switch (header.ColorMapEntrySize) {
case 16:
CColorConverter::convert_A1R5G5B5toA8R8G8B8(colorMap, header.ColorMapLength, palette);
break;
case 24:
CColorConverter::convert_B8G8R8toA8R8G8B8(colorMap, header.ColorMapLength, palette);
break;
case 32:
CColorConverter::convert_B8G8R8A8toA8R8G8B8(colorMap, header.ColorMapLength, palette);
break;
}
delete[] colorMap;
}
// read image
u8 *data = 0;
if (header.ImageType == 1 || // Uncompressed, color-mapped images.
header.ImageType == 2 || // Uncompressed, RGB images
header.ImageType == 3 // Uncompressed, black and white images
) {
const s32 imageSize = header.ImageHeight * header.ImageWidth * (header.PixelDepth / 8);
data = new u8[imageSize];
file->read(data, imageSize);
} else if (header.ImageType == 10) {
// Runlength encoded RGB images
data = loadCompressedImage(file, header);
} else {
os::Printer::log("Unsupported TGA file type", file->getFileName(), ELL_ERROR);
delete[] palette;
return 0;
}
IImage *image = 0;
switch (header.PixelDepth) {
case 8: {
if (header.ImageType == 3) { // grey image
image = new CImage(ECF_R8G8B8,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert8BitTo24Bit((u8 *)data,
(u8 *)image->getData(),
header.ImageWidth, header.ImageHeight,
0, 0, (header.ImageDescriptor & 0x20) == 0);
} else {
switch (header.ColorMapEntrySize) {
case 16:
image = new CImage(ECF_A1R5G5B5, core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert8BitTo16Bit((u8 *)data,
(s16 *)image->getData(),
header.ImageWidth, header.ImageHeight,
(s32 *)palette, 0,
(header.ImageDescriptor & 0x20) == 0);
break;
// Note: 24 bit with palette would need a 24 bit palette, too lazy doing that now (textures will prefer 32-bit later anyway)
default:
image = new CImage(ECF_A8R8G8B8, core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert8BitTo32Bit((u8 *)data,
(u8 *)image->getData(),
header.ImageWidth, header.ImageHeight,
(u8 *)palette, 0,
(header.ImageDescriptor & 0x20) == 0);
break;
}
}
} break;
case 16:
image = new CImage(ECF_A1R5G5B5,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert16BitTo16Bit((s16 *)data,
(s16 *)image->getData(), header.ImageWidth, header.ImageHeight, 0, (header.ImageDescriptor & 0x20) == 0);
break;
case 24:
image = new CImage(ECF_R8G8B8,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert24BitTo24Bit(
(u8 *)data, (u8 *)image->getData(), header.ImageWidth, header.ImageHeight, 0, (header.ImageDescriptor & 0x20) == 0, true);
break;
case 32:
image = new CImage(ECF_A8R8G8B8,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert32BitTo32Bit((s32 *)data,
(s32 *)image->getData(), header.ImageWidth, header.ImageHeight, 0, (header.ImageDescriptor & 0x20) == 0);
break;
default:
os::Printer::log("Unsupported TGA format", file->getFileName(), ELL_ERROR);
break;
}
delete[] data;
delete[] palette;
return image;
}
//! creates a loader which is able to load tgas
IImageLoader *createImageLoaderTGA()
{
return new CImageLoaderTGA();
}
} // end namespace video
} // end namespace irr