pipo declown, yes... I did it so that somebody here (working with NeHe) could either help me get the tutorial working or someone else could just tell me a totally different way
PS: the answer is there, but I can't quite reach it just yet ;)
basic TGA question
ok i modified lessons33 tga load code, and apart from the previous bug i mentioned, this bugfix allso replaces a problem in the header compare code (you only need to compare one byte, why compare the whole thing)
just replace all the content in these files
First we have tga.h
TGAloader.cpp
just replace all the content in these files
First we have tga.h
#ifndef __TGA_H__#define __TGA_H__#pragma comment(lib, "Opengl32.lib") //Link to OpenGL32.lib so we can use OpenGL stuff#include <windows.h> // Standard windows header#include <stdio.h> // Standard I/O header #include <gl\gl.h> // Header for OpenGL32 library#include "texture.h"typedef struct{ GLubyte header[6]; // First 6 Useful Bytes From The Header GLuint bytesPerPixel; // Holds Number Of Bytes Per Pixel Used In The TGA File GLuint imageSize; // Used To Store The Image Size When Setting Aside Ram GLuint temp; // Temporary Variable GLuint type; GLuint Height; //Height of Image GLuint Width; //Width ofImage GLuint Bpp; // Bits Per Pixel} TGA;char tgaheader[12]; // TGA headerchar tgaID[256]; // TGA headerTGA tga; // TGA image databool LoadUncompressedTGA(Texture *, char *, FILE *); // Load an Uncompressed filebool LoadCompressedTGA(Texture *, char *, FILE *); // Load a Compressed file#endif
TGAloader.cpp
/********************************************************************************/Name: TGA.cpp */Header: tga.h */Purpose: Load Compressed and Uncompressed TGA files */Functions: LoadTGA(Texture * texture, char * filename) */ LoadCompressedTGA(Texture * texture, char * filename, FILE * fTGA) */ LoadUncompressedTGA(Texture * texture, char * filename, FILE * fTGA)* /*******************************************************************************/#include "tga.h"/********************************************************************************/name : LoadTGA(Texture * texture, char * filename) */function: Open and test the file to make sure it is a valid TGA file * /parems: texture, pointer to a Texture structure */ filename, string pointing to file to open */********************************************************************************/bool LoadTGA(Texture * texture, char * filename) // Load a TGA file{ FILE * fTGA; // File pointer to texture file fTGA = fopen(filename, "rb"); // Open file for reading if(fTGA == NULL) // If it didn't open.... { MessageBox(NULL, "Could not open texture file", "ERROR", MB_OK); // Display an error message return false; // Exit function } if(fread(&tgaheader, 12, 1, fTGA) == 0) // Attempt to read 12 byte header from file { MessageBox(NULL, "Could not read file header", "ERROR", MB_OK); // If it fails, display an error message if(fTGA != NULL) // Check to seeiffile is still open { fclose(fTGA); // If it is, close it } return false; // Exit function } if(tgaheader[2]==2) // See if header matches the predefined header of { // an Uncompressed TGA image LoadUncompressedTGA(texture, filename, fTGA); // If so, jump to Uncompressed TGA loading code } else if(tgaheader[2]==10) // See if header matches the predefined header of { // an RLE compressed TGA image LoadCompressedTGA(texture, filename, fTGA); // If so, jump to Compressed TGA loading code } else // If header matches neither type { MessageBox(NULL, "TGA file be type 2 or type 10 ", "Invalid Image", MB_OK); // Display an error fclose(fTGA); return false; // Exit function } return true; // All went well, continue on}bool LoadUncompressedTGA(Texture * texture, char * filename, FILE * fTGA) // Load an uncompressed TGA (note, much of this code is based on NeHe's { // TGA Loading code nehe.gamedev.net) if(fread(tga.header, sizeof(tga.header), 1, fTGA) == 0) // Read TGA header { MessageBox(NULL, "Could not read info header", "ERROR", MB_OK); // Display error if(fTGA != NULL) // if file is still open { fclose(fTGA); // Close it } return false; // Return failular } texture->width = tga.header[1] * 256 + tga.header[0]; // Determine The TGA Width (highbyte*256+lowbyte) texture->height = tga.header[3] * 256 + tga.header[2]; // Determine The TGA Height (highbyte*256+lowbyte) texture->bpp = tga.header[4]; // Determine the bits per pixel tga.Width = texture->width; // Copy width into local structure tga.Height = texture->height; // Copy height into local structure tga.Bpp = texture->bpp; // Copy BPP into local structure if((texture->width <= 0) || (texture->height <= 0) || ((texture->bpp != 24) && (texture->bpp !=32))) // Make sure all information is valid { MessageBox(NULL, "Invalid texture information", "ERROR", MB_OK); // Display Error if(fTGA != NULL) // Check if file is still open { fclose(fTGA); // If so, close it } return false; // Return failed } if(tgaheader[0]!=0) { if(fread(&tgaID, tgaheader[0], 1, fTGA) == 0) // Read TGA Id tag { MessageBox(NULL, "Could not read tga ID", "ERROR", MB_OK); // Display Error if(fTGA != NULL) // if file is still open { fclose(fTGA); // Close it } return false; // Return fail } } if(texture->bpp == 24) //If the BPP of the image is 24... { texture->type = GL_RGB; // Set Image type to GL_RGB } else // Else if its 32 BPP { texture->type = GL_RGBA; // Set image type to GL_RGBA } tga.bytesPerPixel = (tga.Bpp / 8); // Compute the number of BYTES per pixel tga.imageSize = (tga.bytesPerPixel * tga.Width * tga.Height); // Compute the total amout ofmemory needed to store data texture->imageData = (GLubyte *)malloc(tga.imageSize); // Allocate that much memory if(texture->imageData == NULL) // If no space was allocated { MessageBox(NULL, "Could not allocate memory for image", "ERROR", MB_OK); // Display Error fclose(fTGA); // Close the file return false; // Return failed } if(fread(texture->imageData, 1, tga.imageSize, fTGA) != tga.imageSize) // Attempt to read image data { MessageBox(NULL, "Could not read image data", "ERROR", MB_OK); // Display Error if(texture->imageData != NULL) // If imagedata has data in it { free(texture->imageData); // Delete data from memory } fclose(fTGA); // Close file return false; // Return failed } // Byte Swapping Optimized By Steve Thomas for(GLuint cswap = 0; cswap < (int)tga.imageSize; cswap += tga.bytesPerPixel) { texture->imageData[cswap] ^= texture->imageData[cswap+2] ^= texture->imageData[cswap] ^= texture->imageData[cswap+2]; } fclose(fTGA); // Close file return true; // Return success}bool LoadCompressedTGA(Texture * texture, char * filename, FILE * fTGA) // Load COMPRESSED TGAs{ if(fread(tga.header, sizeof(tga.header), 1, fTGA) == 0) // Attempt to read header { MessageBox(NULL, "Could not read info header", "ERROR", MB_OK); // Display Error if(fTGA != NULL) // If file is open { fclose(fTGA); // Close it } return false; // Return failed } texture->width = tga.header[1] * 256 + tga.header[0]; // Determine The TGA Width (highbyte*256+lowbyte) texture->height = tga.header[3] * 256 + tga.header[2]; // Determine The TGA Height (highbyte*256+lowbyte) texture->bpp = tga.header[4]; // Determine Bits Per Pixel tga.Width = texture->width; // Copy width to local structure tga.Height = texture->height; // Copy width to local structure tga.Bpp = texture->bpp; // Copy width to local structure if((texture->width <= 0) || (texture->height <= 0) || ((texture->bpp != 24) && (texture->bpp !=32))) //Make sure all texture info is ok { MessageBox(NULL, "Invalid texture information", "ERROR", MB_OK); // If it isnt...Display error if(fTGA != NULL) // Check if file is open { fclose(fTGA); // Ifit is, close it } return false; // Return failed } if(tgaheader[0]!=0) { if(fread(&tgaID, tgaheader[0], 1, fTGA) == 0) // Read TGA Id tag { MessageBox(NULL, "Could not read tga ID", "ERROR", MB_OK); // Display Error if(fTGA != NULL) // if file is still open { fclose(fTGA); // Close it } return false; // Return fail } } tga.bytesPerPixel = (tga.Bpp / 8); // Compute BYTES per pixel tga.imageSize = (tga.bytesPerPixel * tga.Width * tga.Height); // Compute amout of memory needed to store image texture->imageData = (GLubyte *)malloc(tga.imageSize); // Allocate that much memory if(texture->imageData == NULL) // If it wasnt allocated correctly.. { MessageBox(NULL, "Could not allocate memory for image", "ERROR", MB_OK); // Display Error fclose(fTGA); // Close file return false; // Return failed } GLuint pixelcount = tga.Height * tga.Width; // Nuber of pixels in the image GLuint currentpixel = 0; // Current pixel being read GLuint currentbyte = 0; // Current byte GLubyte * colorbuffer = (GLubyte *)malloc(tga.bytesPerPixel); // Storage for 1 pixel do { GLubyte chunkheader = 0; // Storage for "chunk" header if(fread(&chunkheader, sizeof(GLubyte), 1, fTGA) == 0) // Read in the 1 byte header { MessageBox(NULL, "Could not read RLE header", "ERROR", MB_OK); // Display Error if(fTGA != NULL) // If file is open { fclose(fTGA); // Close file } if(texture->imageData != NULL) // If there is stored image data { free(texture->imageData); // Delete image data } return false; // Return failed } if(chunkheader < 128) // If the ehader is < 128, it means the that is the number of RAW color packets minus 1 { // that follow the header chunkheader++; // add 1 to get number of following color values for(short counter = 0; counter < chunkheader; counter++) // Read RAW color values { if(fread(colorbuffer, 1, tga.bytesPerPixel, fTGA) != tga.bytesPerPixel) // Try to read 1 pixel { MessageBox(NULL, "Could not read image data", "ERROR", MB_OK); // IF we cant, display an error if(fTGA != NULL) // See if file is open { fclose(fTGA); // If so, close file } if(colorbuffer != NULL) // See if colorbuffer has data in it { free(colorbuffer); // If so, delete it } if(texture->imageData != NULL) // See if there is stored Image data { free(texture->imageData); // If so, delete it too } return false; // Return failed } // write to memory texture->imageData[currentbyte ] = colorbuffer[2]; // Flip R and B vcolor values around in the process texture->imageData[currentbyte + 1 ] = colorbuffer[1]; texture->imageData[currentbyte + 2 ] = colorbuffer[0]; if(tga.bytesPerPixel == 4) // if its a 32 bpp image { texture->imageData[currentbyte + 3] = colorbuffer[3]; // copy the 4th byte } currentbyte += tga.bytesPerPixel; // Increase thecurrent byte by the number of bytes per pixel currentpixel++; // Increase current pixel by 1 if(currentpixel > pixelcount) // Make sure we havent read too many pixels { MessageBox(NULL, "Too many pixels read", "ERROR", NULL); // if there is too many... Display an error! if(fTGA != NULL) // If there is a file open { fclose(fTGA); // Close file } if(colorbuffer != NULL) // If there is data in colorbuffer { free(colorbuffer); // Delete it } if(texture->imageData != NULL) // If there is Image data { free(texture->imageData); // delete it } return false; // Return failed } } } else // chunkheader > 128 RLE data, next color reapeated chunkheader - 127 times { chunkheader -= 127; // Subteact 127 to get rid of the ID bit if(fread(colorbuffer, 1, tga.bytesPerPixel, fTGA) != tga.bytesPerPixel) // Attempt to read following color values { MessageBox(NULL, "Could not read from file", "ERROR", MB_OK); // If attempt fails.. Display error (again) if(fTGA != NULL) // If thereis a file open { fclose(fTGA); // Close it } if(colorbuffer != NULL) // If there is data in the colorbuffer { free(colorbuffer); // delete it } if(texture->imageData != NULL) // If thereis image data { free(texture->imageData); // delete it } return false; // return failed } for(short counter = 0; counter < chunkheader; counter++) // copy the color into the image data as many times as dictated { // by the header texture->imageData[currentbyte ] = colorbuffer[2]; // switch R and B bytes areound while copying texture->imageData[currentbyte + 1 ] = colorbuffer[1]; texture->imageData[currentbyte + 2 ] = colorbuffer[0]; if(tga.bytesPerPixel == 4) // If TGA images is 32 bpp { texture->imageData[currentbyte + 3] = colorbuffer[3]; // Copy 4th byte } currentbyte += tga.bytesPerPixel; // Increase current byte by the number of bytes per pixel currentpixel++; // Increase pixel count by 1 if(currentpixel > pixelcount) // Make sure we havent written too many pixels { MessageBox(NULL, "Too many pixels read", "ERROR", NULL); // if there is too many... Display an error! if(fTGA != NULL) // If there is a file open { fclose(fTGA); // Close file } if(colorbuffer != NULL) // If there is data in colorbuffer { free(colorbuffer); // Delete it } if(texture->imageData != NULL) // If there is Image data { free(texture->imageData); // delete it } return false; // Return failed } } } } while(currentpixel < pixelcount); // Loop while there are still pixels left fclose(fTGA); // Close the file return true; // return success}
www.flashbang.se | www.thegeekstate.com | nehe.gamedev.net | glAux fix for lesson 6 | [twitter]thegeekstate[/twitter]
ok... it works with their TGAs now for the big test, mine
hmmm... it works kind of, it may be the image editor though I'm currently trying to get a better one, but at least I can make non-transparent TGAs now thanks!!!
hmmm... it works kind of, it may be the image editor though I'm currently trying to get a better one, but at least I can make non-transparent TGAs now thanks!!!
Quote: Original post by lc_overlord
ok i modified lessons33 tga load code, and apart from the previous bug i mentioned, this bugfix allso replaces a problem in the header compare code (you only need to compare one byte, why compare the whole thing)
just replace all the content in these files
First we have tga.h
*** Source Snippet Removed ***
TGAloader.cpp
*** Source Snippet Removed ***
I'm using Dev C++ with the modified lesson 33, but I can't get transparent TGAs, can someone help please
[Edited by - clint8565 on November 28, 2004 1:34:24 PM]
Yea, it's not just the tga load code, because it works just fine.
You have to create the texture as a GL_RGBA instead of GL_RGB
i made parts of the uncompressed image transparent and modified the LoadGLTextures function like this.
then i added
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
before the first gl_Begin in the DrawGLScene function.
You have to create the texture as a GL_RGBA instead of GL_RGB
i made parts of the uncompressed image transparent and modified the LoadGLTextures function like this.
int LoadGLTextures() // Load Bitmaps And Convert To Textures{ int Status=FALSE; // Status Indicator // Load The Bitmap, Check For Errors. if (LoadTGA(&texture[0], "Data/Uncompressed.tga") && LoadTGA(&texture[1], "Data/Compressed.tga")) { Status=TRUE; // Set The Status To TRUE glGenTextures(1, &texture[0].texID); // Create The Texture ( CHANGE ) glBindTexture(GL_TEXTURE_2D, texture[0].texID); glTexImage2D(GL_TEXTURE_2D, 0, 4, texture[0].width, texture[0].height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture[0].imageData); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); if (texture[0].imageData) // If Texture Image Exists ( CHANGE ) { free(texture[0].imageData); // Free The Texture Image Memory ( CHANGE ) } // Typical Texture Generation Using Data From The TGA ( CHANGE ) glGenTextures(1, &texture[1].texID); // Create The Texture ( CHANGE ) glBindTexture(GL_TEXTURE_2D, texture[1].texID); glTexImage2D(GL_TEXTURE_2D, 0, 3, texture[1].width, texture[1].height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture[1].imageData); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); if (texture[1].imageData) // If Texture Image Exists ( CHANGE ) { free(texture[1].imageData); // Free The Texture Image Memory ( CHANGE ) } } return Status; // Return The Status}
then i added
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
before the first gl_Begin in the DrawGLScene function.
www.flashbang.se | www.thegeekstate.com | nehe.gamedev.net | glAux fix for lesson 6 | [twitter]thegeekstate[/twitter]
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