加載TGA文件並將其與OpenGL一起使用

我目前正在嘗試使用C++加載標記文件並使用OpenGL進行渲染。目前，所有顏色都混在一起（紅色變成藍色，綠色變成紅色，藍色變成綠色）。我目前的代碼放入視頻內存是。加載TGA文件並將其與OpenGL一起使用

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);

其中數據是像素數據，其餘是自我解釋。這些文件是保存的，沒有壓縮是從Photoshop中保存的24位。

來源

2011-08-12 Jjack

後一個完整的，最小的程序演示該問題。 – genpfault

@Jjack：也許你可以發佈你的圖片嗎？ –

更改爲： glTextImage2D（GL_TEXTURE_2D，0，GL_RGB，widht，height，0，GL_BRG，GL_UNSIGNED_BYTE，data）; 這僅僅是因爲你閱讀了其他顏色順序的TGA（或者你讀錯了順序）。您應該將第二個GL_RBG更改爲GL_BRG。更多內容請看這裏：http：//www.opengl.org/sdk/docs/man/xhtml/glTexImage2D.xml –

您的glTexImage2D是正確的，所以這不是問題。

我確實需要（加載TGA文件時）交換顏色成分。試試這個：

typedef struct 
{ 
    unsigned char imageTypeCode; 
    short int imageWidth; 
    short int imageHeight; 
    unsigned char bitCount; 
    unsigned char *imageData; 
} TGAFILE; 

bool LoadTGAFile(char *filename, TGAFILE *tgaFile) 
{ 
    FILE *filePtr; 
    unsigned char ucharBad; 
    short int sintBad; 
    long imageSize; 
    int colorMode; 
    unsigned char colorSwap; 

    // Open the TGA file. 
    filePtr = fopen(filename, "rb"); 
    if (filePtr == NULL) 
    { 
     return false; 
    } 

    // Read the two first bytes we don't need. 
    fread(&ucharBad, sizeof(unsigned char), 1, filePtr); 
    fread(&ucharBad, sizeof(unsigned char), 1, filePtr); 

    // Which type of image gets stored in imageTypeCode. 
    fread(&tgaFile->imageTypeCode, sizeof(unsigned char), 1, filePtr); 

    // For our purposes, the type code should be 2 (uncompressed RGB image) 
    // or 3 (uncompressed black-and-white images). 
    if (tgaFile->imageTypeCode != 2 && tgaFile->imageTypeCode != 3) 
    { 
     fclose(filePtr); 
     return false; 
    } 

    // Read 13 bytes of data we don't need. 
    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 the image's width and height. 
    fread(&tgaFile->imageWidth, sizeof(short int), 1, filePtr); 
    fread(&tgaFile->imageHeight, sizeof(short int), 1, filePtr); 

    // Read the bit depth. 
    fread(&tgaFile->bitCount, sizeof(unsigned char), 1, filePtr); 

    // Read one byte of data we don't need. 
    fread(&ucharBad, sizeof(unsigned char), 1, filePtr); 

    // Color mode -> 3 = BGR, 4 = BGRA. 
    colorMode = tgaFile->bitCount/8; 
    imageSize = tgaFile->imageWidth * tgaFile->imageHeight * colorMode; 

    // Allocate memory for the image data. 
    tgaFile->imageData = (unsigned char*)malloc(sizeof(unsigned char)*imageSize); 

    // Read the image data. 
    fread(tgaFile->imageData, sizeof(unsigned char), imageSize, filePtr); 

    // Change from BGR to RGB so OpenGL can read the image data. 
    for (int imageIdx = 0; imageIdx < imageSize; imageIdx += colorMode) 
    { 
     colorSwap = tgaFile->imageData[imageIdx]; 
     tgaFile->imageData[imageIdx] = tgaFile->imageData[imageIdx + 2]; 
     tgaFile->imageData[imageIdx + 2] = colorSwap; 
    } 

    fclose(filePtr); 
    return true; 
}

來源

2011-08-13 10:52:44 Wroclai

小提示：它返回一個布爾值，一個布爾值* –

請修改'Read 13 bytes'的評論到'讀取9個字節'就像代碼中的int一樣 –

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Width,Height, 0, 
     GL_BGRA_EXT, GL_UNSIGNED_BYTE, Pixels);

試試這個我有同樣的問題每一件事情是藍色它有紋理圖案只是不顏色

來源

2013-11-05 21:29:42 Mastereus

加載TGA文件並將其與OpenGL一起使用

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