void GImage::decodeTGA(
BinaryInput& input) {
// This is a simple TGA loader that can handle uncompressed
// truecolor TGA files (TGA type 2).
// Verify this is a TGA file by looking for the TRUEVISION tag.
int pos = input.getPosition();
input.setPosition(input.size() - 18);
std::string tag = input.readString(16);
if (tag != "TRUEVISION-XFILE") {
throw Error("Not a TGA file", input.getFilename());
}
input.setPosition(pos);
int IDLength = input.readUInt8();
int colorMapType = input.readUInt8();
int imageType = input.readUInt8();
(void)colorMapType;
// 2 is the type supported by this routine.
if (imageType != 2 && imageType != 10) {
throw Error("TGA images must be type 2 (Uncompressed truecolor) or 10 (Run-length truecolor)", input.getFilename());
}
// Color map specification
input.skip(5);
// Image specification
// Skip x and y offsets
input.skip(4);
m_width = input.readInt16();
m_height = input.readInt16();
int colorDepth = input.readUInt8();
if ((colorDepth != 24) && (colorDepth != 32)) {
throw Error("TGA files must be 24 or 32 bit.", input.getFilename());
}
if (colorDepth == 32) {
m_channels = 4;
} else {
m_channels = 3;
}
// Image descriptor contains overlay data as well
// as data indicating where the origin is
int imageDescriptor = input.readUInt8();
(void)imageDescriptor;
// Image ID
input.skip(IDLength);
m_byte = (uint8*)m_memMan->alloc(m_width * m_height * m_channels);
debugAssert(m_byte);
// Pixel data
int x;
int y;
if (imageType == 2) {
// Uncompressed
if (m_channels == 3) {
for (y = m_height - 1; y >= 0; --y) {
for (x = 0; x < m_width; ++x) {
int i = (x + y * m_width) * 3;
readBGR(m_byte + i, input);
}
}
} else {
for (y = m_height - 1; y >= 0; --y) {
for (x = 0; x < m_width; ++x) {
int i = (x + y * m_width) * 4;
readBGRA(m_byte + i, input);
}
}
}
} else if (imageType == 10) {
// Run-length encoded
for (y = m_height - 1; y >= 0; --y) {
for (int x = 0; x < m_width; /* intentionally no x increment */) {
// The specification guarantees that no packet will wrap past the end of a row
const uint8 repetitionCount = input.readUInt8();
const uint8 numValues = (repetitionCount & (~128)) + 1;
int byteOffset = (x + y * m_width) * 3;
if (repetitionCount & 128) {
// When the high bit is 1, this is a run-length packet
if (m_channels == 3) {
Color3uint8 value;
readBGR((uint8*)(&value), input);
for (int i = 0; i < numValues; ++i, ++x) {
for (int b = 0; b < 3; ++b, ++byteOffset) {
m_byte[byteOffset] = value[b];
}
}
} else {
Color4uint8 value;
readBGRA((uint8*)(&value), input);
for (int i = 0; i < numValues; ++i, ++x) {
for (int b = 0; b < 3; ++b, ++byteOffset) {
m_byte[byteOffset] = value[b];
}
}
}
} else {
// When the high bit is 0, this is a raw packet
for (int i = 0; i < numValues; ++i, ++x, byteOffset += m_channels) {
readBGR(m_byte + byteOffset, input);
}
}
}
}
} else {
alwaysAssertM(false, "Unsupported type");
}
}
void GImage::decodeTGA(
BinaryInput& input) {
// This is a simple TGA loader that can handle uncompressed
// truecolor TGA files (TGA type 2).
// Verify this is a TGA file by looking for the TRUEVISION tag.
int pos = input.getPosition();
input.setPosition(input.size() - 18);
std::string tag = input.readString(16);
if (tag != "TRUEVISION-XFILE") {
throw Error("Not a TGA file", input.getFilename());
}
input.setPosition(pos);
int IDLength = input.readUInt8();
int colorMapType = input.readUInt8();
int imageType = input.readUInt8();
(void)colorMapType;
// 2 is the type supported by this routine.
if (imageType != 2) {
throw Error("TGA images must be type 2 (Uncompressed truecolor)", input.getFilename());
}
// Color map specification
input.skip(5);
// Image specification
// Skip x and y offsets
input.skip(4);
m_width = input.readInt16();
m_height = input.readInt16();
int colorDepth = input.readUInt8();
if ((colorDepth != 24) && (colorDepth != 32)) {
throw Error("TGA files must be 24 or 32 bit.", input.getFilename());
}
if (colorDepth == 32) {
m_channels = 4;
} else {
m_channels = 3;
}
// Image descriptor contains overlay data as well
// as data indicating where the origin is
int imageDescriptor = input.readUInt8();
(void)imageDescriptor;
// Image ID
input.skip(IDLength);
m_byte = (uint8*)m_memMan->alloc(m_width * m_height * m_channels);
debugAssert(m_byte);
// Pixel data
int x;
int y;
if (m_channels == 3) {
for (y = m_height - 1; y >= 0; --y) {
for (x = 0; x < m_width; ++x) {
int b = input.readUInt8();
int g = input.readUInt8();
int r = input.readUInt8();
int i = (x + y * m_width) * 3;
m_byte[i + 0] = r;
m_byte[i + 1] = g;
m_byte[i + 2] = b;
}
}
} else {
for (y = m_height - 1; y >= 0; --y) {
for (x = 0; x < m_width; ++x) {
int b = input.readUInt8();
int g = input.readUInt8();
int r = input.readUInt8();
int a = input.readUInt8();
int i = (x + y * m_width) * 4;
m_byte[i + 0] = r;
m_byte[i + 1] = g;
m_byte[i + 2] = b;
m_byte[i + 3] = a;
}
}
}
}
