improved TGA handling

1 files changed, 250 insertions, 150 deletions

diff --git a/src/render/tga.cc b/src/render/tga.cc
index 0eb2ef6..c7f4fc1 100644
--- a/src/render/tga.cc
+++ b/src/render/tga.cc
@@ -1,185 +1,285 @@
 /*
-	Ronny Andr�Reierstad
-	http://www.morrowland.com
-	http://www.morrowland.com/apron/tut_gl.php
-	apron@morrowland.com
+   render/tga.cc
+   This file is part of the Osirion project and is distributed under
+   the terms of the GNU General Public License version 2
 */
 
+/*
+   Documentation and examples on the TGA file format:
+
+   http://www.dca.fee.unicamp.br/~martino/disciplinas/ea978/tgaffs.pdf
+   http://www.fileformat.info/format/tga/egff.htm
+   http://www.morrowland.com/apron/tut_gl.php
+
+   Notes
+
+   TGA image type                          Colormap  RLE
+    0         No image data included in file No       No
+    1         Colormapped image data         Yes      No
+    2         Truecolor image data           No       No
+    3         Monochrome image data          No       No
+    9         Colormapped image data         Yes      Yes
+    10        Truecolor image data           No       Yes
+    11        Monochrome image data          No       Yes
+	
+   TGA multi-byte integer values have LSB first
+*/
+
+
+
+#include <fstream>
+#include <sstream>
+#include <string>
+
 #include "filesystem/filesystem.h"
 #include "render/tga.h"
 #include "sys/sys.h"
-#include "GL/gl.h"
-#include <GL/glu.h>
+
+const unsigned char		TGA_NONE = 0;
+const unsigned char		TGA_TRUECOLOR = 2;
+const unsigned char 		TGA_TRUECOLOR_RLE = 10;
 
 namespace render
 {
 
-/////////////////////////////////////////////////////////////////////////////////////////////////
-//										TGA TEXTURE LOADER
-/////////////////////////////////////////////////////////////////////////////////////////////////
-bool TGA::texture(GLuint textureArray[], const char *filename, int ID)
+Image *TGA::load(const char *filename)
 {
+	Image *image = 0;
+
 	if (!filename)
-		return false;
-		
-	image *pBitMap = load(filename);
-	if (!pBitMap) {
-		//con_warn << "Could not load " << filename << std::endl;
-		return false;
+		return 0;
+
+	filesystem::File *tga_file = filesystem::open(filename);
+	if (!tga_file) {
+		con_warn << "Could not open " << filename << std::endl;
+		return 0;
 	}
-	
-	glGenTextures(1, &textureArray[ID]);
-	glBindTexture(GL_TEXTURE_2D, textureArray[ID]);
-	int textureType = GL_RGB;
-	if (pBitMap->channels == 4)	textureType = GL_RGBA;
-	gluBuild2DMipmaps(GL_TEXTURE_2D, pBitMap->channels, pBitMap->size_x, pBitMap->size_y, textureType, GL_UNSIGNED_BYTE, pBitMap->data);
-	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR_MIPMAP_LINEAR);
-	
-	if (pBitMap) {
-		if (pBitMap->data) {
-			free(pBitMap->data);
-		}
-		free(pBitMap);
+
+	// TGA header
+	unsigned char header[18];
+        memset(header, 0, sizeof(header));
+
+	if (!tga_file->read(header, 18)) {
+		con_warn << "Error reading " << filename << std::endl;
+		filesystem::close(tga_file);
+		return 0;
 	}
 
-	return true;
-}
+        // byte 0       - image ID field lenght
+	unsigned int tga_idlength = header[0];
 
+        // byte 1       - color map type
+	unsigned int tga_colormap = header[1];
 
-TGA::image *TGA::load(const char *filename)
-{
-	image *pImgData			= NULL;
-	//FILE *pFile			= NULL;
-	GLushort width			= 0;
-	GLushort height			= 0;
-	GLubyte length			= 0;
-	GLubyte imgType			= 0;
-	GLubyte bits			= 0;
-	GLushort channels		= 0;
-	GLushort stride			= 0;
-	
-	filesystem::File *f = filesystem::open(filename);
-	if (!f)
-		return 0;
-		
-	pImgData = (image*)malloc(sizeof(image));
-	pImgData->data = 0;
-	
-	f->read((void *)&length, sizeof(GLubyte));
-	f->skip(1);
-	f->read((void *)&imgType, sizeof(GLubyte));
-	f->skip(9);
-	f->read((void *)&width,  sizeof(GLushort));
-	f->read((void *)&height, sizeof(GLushort));
-	f->read((void *)&bits,   sizeof(GLubyte));
-	f->skip(length +1);
+        // byte 2       - image type
+	unsigned int tga_type = header[2];
+
+        // byte 3+4     - color map first entry index
+	//unsigned int tga_colormap_first = header[3] + (header[4] << 8 );
+
+	// byte 5+6	- color map length (in bits)
+	unsigned int tga_color_map_length = header[5] +(header[6] << 8 );
+
+	// byte 7 	- color map entry length
+	unsigned int tga_colormap_entry = header[7];
+
+	// byte 8+9	- image x origin
+	// byte 10+11	- image y origin
+        // byte 12+13   - image width (LSB first)
+	unsigned int tga_width = header[12] + (header[13] << 8);
+
+        // byte 14+15   - image height (LSB first)
+	unsigned int tga_height = header[14] + (header[15] << 8);
+
+        // byte 16      - image color depth (in bits)
+	unsigned int tga_depth = header[16];
+
+        // byte 17      - image descriptor byte
+	unsigned int tga_descriptor = header[17];
 	
-	con_debug << "  " << filename << " " << width << "x" << height << "x" << (int) bits << "bpp" << std::endl;
+	con_debug << "  " << filename << " "
+		<< tga_width << "x" << tga_height << "x" << tga_depth << "bpp" << std::endl;
 	
-	if (imgType != TGA_RLE) {
-		// Check for 24 or 32 Bit
-		if (bits == 24 || bits == 32) {
+	// read the image id if there is one
+	if (tga_idlength)
+		tga_file->skip(tga_idlength);
+
+	// read color map data (even for non-color mapped images)
+	if (tga_colormap) {
+		if (tga_colormap > 1)
+			con_warn << filename << ": invalid color map type!" << std::endl;
 		
-			channels = bits / 8;
-			stride = channels * width;
-			pImgData->data = new unsigned char[stride * height];
-			
-			for (GLushort y = 0; y < height; y++) {
-				unsigned char *pLine = &(pImgData->data[stride * y]);
-				
-				f->read((void *)pLine, stride);
-				
-				for (GLushort i = 0; i < stride; i += channels) {
-					int temp     = pLine[i];
-					pLine[i]     = pLine[i + 2];
-					pLine[i + 2] = temp;
-				}
+		tga_file->skip(tga_color_map_length*tga_colormap_entry);
+	}
+
+	unsigned int index = 0;
+	unsigned int channels = tga_depth / 8;
+
+	switch(tga_type) {
+
+	case TGA_NONE:
+		con_warn << "Error reading " << filename 
+			<< ": no image data!" << std::endl;
+		filesystem::close(tga_file);
+		return 0;
+		break;
+
+	case TGA_TRUECOLOR:
+		if ((tga_depth == 24) || (tga_depth == 32)) {
+
+			image = new Image(tga_width, tga_height, channels);
+
+			for (size_t i = 0; i < tga_width * tga_height; i++) {
+				tga_file->read((void *)(*image)[i*(size_t)channels], channels);
 			}
-		}
-		
-		// Check for 16 Bit
-		else if (bits == 16) {
-			unsigned short pixels = 0;
-			int r=0, g=0, b=0;
+
+			image->swap_channels();
+
+		} else if (tga_depth == 16) {
 			
 			channels = 3;
-			stride = channels * width;
-			pImgData->data = new unsigned char[stride * height];
-			
-			for (int i = 0; i < width*height; i++) {
-				f->read((void *)&pixels, sizeof(GLushort));
-				
-				b = (pixels & 0x1f) << 3;
-				g = ((pixels >> 5) & 0x1f) << 3;
-				r = ((pixels >> 10) & 0x1f) << 3;
+			image = new Image(tga_width, tga_height,channels);
+
+			for (size_t i =0; i < tga_width * tga_height; i++) {
+				// unpack one pixel
+				unsigned char pixel_data[2];
+				tga_file->read((void *)pixel_data, 2);
+				unsigned int unpacked = pixel_data[0] + pixel_data[1]* 0xff;
+
+				unsigned int b = (unpacked & 0x1f) << 3;
+                                unsigned int g = ((unpacked >> 5) & 0x1f) << 3;
+                                unsigned int r = ((unpacked >> 10) & 0x1f) << 3;
 				
-				pImgData->data[i * 3 + 0] = r;
-				pImgData->data[i * 3 + 1] = g;
-				pImgData->data[i * 3 + 2] = b;
+				// store it
+				image->data()[i * channels] = (unsigned char) b;
+				image->data()[i * channels+1] = (unsigned char) g;
+				image->data()[i * channels+2] = (unsigned char) r;
 			}
-		} else
-			return NULL;
-	} else {
-		GLubyte rleID = 0;
-		int colorsRead = 0;
-		channels = bits / 8;
-		stride = channels * width;
-		
-		pImgData->data = new unsigned char[stride * height];
-		GLubyte *pColors = new GLubyte [channels];
-		
-		int i = 0;
-		while (i < width*height) {
+		} else {
+			con_warn << "Error reading " << filename 
+				<< ": unsupported image depth '" << tga_depth << "'!" << std::endl;
+			filesystem::close(tga_file);
+			return 0;	
+		}
 		
-			f->read((void *)&rleID, sizeof(GLubyte));
-			
+		break;
+
+	case TGA_TRUECOLOR_RLE:
+
+		image = new Image(tga_width, tga_height, channels);
+
+		while (index < tga_width * tga_height) {
+			unsigned char rle = 0;
+			unsigned char pixel_data[channels];
+
+			// read RLE packet byte
+			tga_file->read(&rle, 1);
 			
-			if (rleID < 128)	{
-				rleID++;
-				
-				while (rleID) {
-					f->read((void *)pColors, sizeof(GLubyte) * channels);
-					
-					pImgData->data[colorsRead + 0] = pColors[2];
-					pImgData->data[colorsRead + 1] = pColors[1];
-					pImgData->data[colorsRead + 2] = pColors[0];
-					
-					if (bits == 32)	pImgData->data[colorsRead + 3] = pColors[3];
-					
-					i++;
-					rleID--;
-					colorsRead += channels;
-				}
+			if (rle < 128) {
+				rle++; // rle contains the number of pixels-1
+				tga_file->read((void *)(*image)[index*channels], rle*channels);
+				index += rle;
+
 			} else {
-				rleID -= 127;
-				
-				f->read((void *)pColors, sizeof(GLubyte) * channels);
-				
-				while (rleID) {
-					pImgData->data[colorsRead + 0] = pColors[2];
-					pImgData->data[colorsRead + 1] = pColors[1];
-					pImgData->data[colorsRead + 2] = pColors[0];
-					
-					if (bits == 32)	pImgData->data[colorsRead + 3] = pColors[3];
-					
-					i++;
-					rleID--;
-					colorsRead += channels;
+				rle -= 127; // rle contains 128 + the number of identical pixels-1
+				tga_file->read(pixel_data, channels);
+			
+				while (rle) {
+					memcpy((void *)(*image)[index*channels], (void *)pixel_data, channels);
+					index++;
+					rle--;
 				}
 			}
 		}
-		delete pColors;
-	}
-	
-	filesystem::close(f);
-	
-	
-	pImgData->channels  = channels;
-	pImgData->size_x    = width;
-	pImgData->size_y    = height;
+
+		image->swap_channels();
+
+		break;
 	
-	return pImgData;
+	default:
+		con_warn << "Error reading " << filename 
+			<< ": unsupported TGA type '" << (int) tga_type << "'!" << std::endl;
+		filesystem::close(tga_file);
+		return 0;
+	}
+
+	filesystem::close(tga_file);
+
+	if ((tga_descriptor & 0x20) == 0x0) {
+		// origin at bottom left
+		image->flip();
+	}
+
+	if ((tga_descriptor & 0x10) == 0x10) {
+		con_warn << filename << ": descriptor bit 4 (left-right) set!" << std::endl;
+	}
+
+	return image;
+}
+
+void TGA::save(const char *filename, Image & image)
+{
+	if (!filename)
+		return;
+
+	std::ofstream ofs(filename);
+
+        if (!ofs.is_open()) {
+                con_warn << "Could not write " << filename << std::endl;
+                return;
+        }
+
+	// write TGA header
+	unsigned char header[18];
+	memset(header, 0, sizeof(header));
+
+	// byte 0       - image ID field lenght         = 0 (no image ID field present)
+        // byte 1       - color map type                = 0 (no palette present)
+        // byte 2       - image type                    = 2 (truecolor without RLE)
+        header[2] = TGA_TRUECOLOR;
+        // byte 3-11    - palette data (not used)
+        // byte 12+13   - image width
+        header[12] = (image.width() & 0xff);
+        header[13] = ((image.width() >> 8) & 0xff);
+        // byte 14+15   - image height
+        header[14] = (image.height() & 0xff);
+        header[15] = ((image.height() >> 8) & 0xff);
+        // byte 16      - image color depth             = 24 (RGB) or 32 (RGBA)
+        header[16] = image.channels() * 8;
+        // byte 17      - image descriptor byte		= 0x20 (origin at bottom left)
+        header[17] = 0x20;
+
+	// write header
+        ofs.write((char *)header, sizeof(header));
+
+	// write image data
+	// TGA has the R and B channels switched
+	unsigned char buf[image.channels()];
+	for (int y = image.height()-1; y >= 0; y--) {
+		for (size_t x = 0; x < image.width(); x++) {
+			buf[0] = *image[y*image.width()*image.channels()+x*image.channels()+2];
+			buf[1] = *image[y*image.width()*image.channels()+x*image.channels()+1];
+			buf[2] = *image[y*image.width()*image.channels()+x*image.channels()];
+
+			if (image.channels() == 4)
+				buf[3] = *image[y*image.width()*image.channels()+x*image.channels()+3];
+
+        		ofs.write((char *)buf, image.channels());
+		}
+	}
+
+	// write footer (optional, but the specification recommends it)
+	char footer[26];
+	memset(footer, 0, sizeof(footer));
+	strncpy(&footer[8] , "TRUEVISION-XFILE", 16);
+	footer[24] = '.';
+	footer[25] = 0;
+	ofs.write(footer, sizeof(footer));
+
+	// close file
+	ofs.close();
+
+	con_print << "Wrote " << filename << std::endl;
 }
 
 }