Question

我创建了一个带有opengl功能的x11窗口，我需要在窗口大小大于图像的背景上加载图像（jpeg | png），这没关系。我冲浪得到像使用DevIL或免费图像的重新录制。我不知道使用哪一个。我用a link to sample code中给出的示例代码设置了opengl窗口，我想在void renderGL（）中编写代码，以便将图像作为背景。你能告诉我使用哪个图像库，并在可能的情况下提供代码。

还有在opengl中绘制颜色像素的方法。我需要一个在窗口中绘制像素的函数，我必须单独提供x，y像素位置和rgb颜色（unsigned int）.....

Answer 1

我不是一个opengl程序员，但不知怎的，我这样做了和它的工作


 ilInit(); /* Initialization of DevIL */
ilGenImages(1, &texid); /* Generation of one image name */
ilBindImage(texid); /* Binding of image name */
success = ilLoadImage(backgroundimage); /* Loading of image "image.jpg" */
iWidth = ilGetInteger(IL_IMAGE_WIDTH);
iHeight = ilGetInteger(IL_IMAGE_HEIGHT);
if (success){ 
success = ilConvertImage(IL_RGBA, IL_UNSIGNED_BYTE); // Convert every colour component into unsigned byte,replace IL_RGB with IL_RGBA  for alpha channel
}   

glGenTextures(1, &image); /* Texture name generation */
glBindTexture(GL_TEXTURE_2D, image); /* Binding of texture name */
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
glTexImage2D(GL_TEXTURE_2D, 0, ilGetInteger(IL_IMAGE_BPP), ilGetInteger(IL_IMAGE_WIDTH),

ilGetInteger(IL_IMAGE_HEIGHT), 0, ilGetInteger(IL_IMAGE_FORMAT), GL_UNSIGNED_BYTE,
ilGetData()); /* Texture specification */

glRotatef(roll, 0.0f,0.0f, 10.0f);     
glOrtho(0.0, float(width), float(height), 0.0, 0.0, 100.0);
glMatrixMode(GL_MODELVIEW);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClearDepth(0.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();   // Reset The Modelview Matrix

glBindTexture(GL_TEXTURE_2D, image);    // Select The First Image Texture
glBegin(GL_QUADS);// Start Drawing A Textured Quad
glTexCoord2i(0, 0); glVertex2f(width/2-iWidth/2,height/2-iHeight/2);
glTexCoord2i(0, 1); glVertex2f(width/2-iWidth/2,height/2+iHeight/2);
glTexCoord2i(1, 1); glVertex2f(width/2+iWidth/2,height/2+iHeight/2);
glTexCoord2i(1, 0); glVertex2f(width/2+iWidth/2,height/2-iHeight/2);        
glEnd();

使用GLX（opengl和Xlib）设置图像（jpeg | png）背景

1 个答案: