LibD/src/Texture/Texture.cpp

250 lines
7.4 KiB
C++

#include "../System/Debug.h"
#include "Texture.h"
#include <iostream>
using namespace std;
static GLuint boundTexture = 0;
static bool IsBGR(SDL_Surface* surf) {
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
return (surf->format->Rmask & 0x00FF0000) &&
(surf->format->Bmask & 0x000000FF);
#else
return (surf->format->Bmask & 0xFF000000) &&
(surf->format->Rmask & 0x0000FF00);
#endif
}
int BuildTexture(const char* filename, GLuint* texID, GLint param, bool genMips) {
// Create a storage space for the texture.
SDL_Surface* textureImage;
// Format to pass to texture generation method.
GLint format;
GLint internalFormat;
// Load the image, check for errors, if it isn't found, quit.
textureImage = IMG_Load(filename);
if(!textureImage) {
Debug::logger->message("Warning: could not load %s", filename);
return false;
}
switch(textureImage->format->BitsPerPixel) {
case 8:
internalFormat = format = GL_ALPHA;
break;
case 16:
internalFormat = format = GL_LUMINANCE_ALPHA;
break;
case 24:
internalFormat = GL_RGB;
if (IsBGR(textureImage))
format = GL_BGR_EXT;
else
format = GL_RGB;
break;
case 32:
internalFormat = GL_RGBA;
if (IsBGR(textureImage))
format = GL_BGR_EXT;
else
format = GL_RGBA;
break;
default:
format = internalFormat = GL_NONE;
}
if(internalFormat == GL_NONE || format == GL_NONE) {
Debug::logger->message("Warning: invalid texture format for %s", filename);
SDL_FreeSurface(textureImage);
return false;
}
// Create the texture.
glGenTextures(1, texID);
// Typical texture generation using data from the bitmap.
BindTexture(*texID);
// Setup filtering.
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, param);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, param);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
if(genMips) {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
// Generate the textures and mipmaps.
gluBuild2DMipmaps(GL_TEXTURE_2D, internalFormat, textureImage->w,
textureImage->h, format, GL_UNSIGNED_BYTE,
textureImage->pixels);
} else {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, textureImage->w,
textureImage->h, 0, format, GL_UNSIGNED_BYTE,
textureImage->pixels);
}
// Free up the memory we used.
SDL_FreeSurface(textureImage);
return true;
}
int LoadTGAFile(const char* filename, TGAFILE* tgaFile) {
FILE* filePtr; // Pointer to our texture.
unsigned char ucharBad; // Garbage unsigned char data.
short int sintBad; // Garbage short int data.
long imageSize; // size of the TGA image.
int colorMode; // 4 for RGBA or 3 for RGB.
long imgIndex; // counter variable.
unsigned char colorSwap; // Swap variable.
// Open the TGA file.
filePtr = fopen(filename, "rb");
if(!filePtr)
return 0;
// Read the first two bytes of garbage.
fread(&ucharBad, sizeof(unsigned char), 1, filePtr);
fread(&ucharBad, sizeof(unsigned char), 1, filePtr);
// Read in the image type.
fread(&tgaFile->textureTypeCode, sizeof(unsigned char), 1, filePtr);
// The texture type should be either 2(color) or 3(greyscale).
if((tgaFile->textureTypeCode != 2) && (tgaFile->textureTypeCode != 3)) {
fclose(filePtr);
return 0;
}
// Read 13 bytes of garbage data.
fread(&sintBad, sizeof(short int), 1, filePtr);
fread(&sintBad, sizeof(short int), 1, filePtr);
fread(&ucharBad, sizeof(unsigned char), 1, filePtr);
fread(&sintBad, sizeof(short int), 1, filePtr);
fread(&sintBad, sizeof(short int), 1, filePtr);
// Read image dimensions.
fread(&tgaFile->textureWidth, sizeof(short int), 1, filePtr);
fread(&tgaFile->textureHeight, sizeof(short int), 1, filePtr);
// Read image bit depth.
fread(&tgaFile->bitCount, sizeof(unsigned char), 1, filePtr);
// Read 1 byte of garbage data.
fread(&ucharBad, sizeof(unsigned char), 1, filePtr);
// colorMode -> 3 = BGR, 4 = BGRA
colorMode = tgaFile->bitCount / 8;
imageSize = tgaFile->textureWidth * tgaFile->textureHeight * colorMode;
// Allocate memory for image data.
tgaFile->textureData = (unsigned char*)malloc(sizeof(unsigned char)*imageSize);
// Read in the image data.
fread(tgaFile->textureData, sizeof(unsigned char), imageSize, filePtr);
// Change BGR to RGB so OpenGL can read the data.
for(imgIndex = 0; imgIndex < imageSize; imgIndex += colorMode) {
colorSwap = tgaFile->textureData[imgIndex];
tgaFile->textureData[imgIndex] = tgaFile->textureData[imgIndex + 2];
tgaFile->textureData[imgIndex + 2] = colorSwap;
}
// Close the file.
fclose(filePtr);
return 1;
}
int WriteTGAFile(const char* filename, short int width, short int height, unsigned char* imageData) {
unsigned char byteSkip; // Use to fill in the data fields that we don't care about.
short int shortSkip;
unsigned char imageType; // Image type that we are writing to file.
int colorMode;
unsigned char colorSwap;
int imgIndex;
unsigned char bitDepth;
long imageSize;
FILE* filePtr;
// Create a file for writing to binary mode.
filePtr = fopen(filename, "wb");
if(!filePtr) {
fclose(filePtr);
return 0;
}
imageType = 2; // RGB, uncompressed.
bitDepth = 24; // 24-bitdepth.
colorMode = 3; // RGB color mode.
byteSkip = 0;
shortSkip = 0;
// Write 2 bytes of data.
fwrite(&byteSkip, sizeof(unsigned char), 1, filePtr);
fwrite(&byteSkip, sizeof(unsigned char), 1, filePtr);
// Write image type.
fwrite(&imageType, sizeof(unsigned char), 1, filePtr);
fwrite(&shortSkip, sizeof(short int), 1, filePtr);
fwrite(&shortSkip, sizeof(short int), 1, filePtr);
fwrite(&byteSkip, sizeof(unsigned char), 1, filePtr);
fwrite(&shortSkip, sizeof(short int), 1, filePtr);
fwrite(&shortSkip, sizeof(short int), 1, filePtr);
// Write image dimensions.
fwrite(&width, sizeof(short int), 1, filePtr);
fwrite(&height, sizeof(short int), 1, filePtr);
fwrite(&bitDepth, sizeof(unsigned char), 1, filePtr);
// Write 1 byte of data
fwrite(&byteSkip, sizeof(unsigned char), 1, filePtr);
// Calculate the image size.
imageSize = width * height * colorMode;
// Change the image data from RGB to BGR
for(imgIndex = 0; imgIndex < imageSize; imgIndex += colorMode) {
colorSwap = imageData[imgIndex];
imageData[imgIndex] = imageData[imgIndex + 2];
imageData[imgIndex + 2] = colorSwap;
}
// Write the image data.
fwrite(imageData, sizeof(unsigned char), imageSize, filePtr);
// Close the file.
fclose(filePtr);
return 1;
}
void BindTexture(GLuint texID) {
if(boundTexture != texID){
glBindTexture(GL_TEXTURE_2D, texID);
boundTexture = texID;
}
}
Texture::Texture() {
texID = 0;
width = 0;
height = 0;
}
Texture::~Texture() {
if(texID != 0) {
glDeleteTextures(1, &texID);
texID = 0;
}
}
bool Texture::Load(const char* filename) {
if(BuildTexture(filename, &texID, GL_CLAMP, false)) {
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &width);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &height);
return true;
}
return false;
}