我正在使用 openGL 四缓冲区渲染立体 3D 图像(我对 openGL 还很陌生)。
我遇到了一个关于如何为每个后台缓冲区定义输出纹理的问题,我想这是通过定义输出颜色(对应于指定的纹理)在片段缓冲区中完成的。
这是我用于着色器源的代码:
// Shader sources
const GLchar* vertexSource =
"#version 150 core\n"
"in vec2 position;"
"in vec3 color;"
"in vec2 texcoord;"
"out vec3 Color;"
"out vec2 Texcoord;"
"void main() {"
" Color = color;"
" Texcoord = texcoord;"
" gl_Position = vec4(position, 0.0, 1.0);"
"}"; // Vertex buffer source
const GLchar* fragmentSource =
"#version 150 core\n"
"in vec3 Color;"
"in vec2 Texcoord;"
"out vec4 outColor;"
"uniform sampler2D texRight;"
"uniform sampler2D texLeft;"
"void main() {"
" outColor = texture(texRight, Texcoord);"
" outColor = texture(texLeft, Texcoord);"
"}"; // Fragment buffer source
这是我用来填充后台缓冲区的代码,我在 freeglut 上下文窗口的显示函数中使用了它。
// Clear Buffers
glDrawBuffer(GL_BACK);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(0.0f, 0.0f, 0.0f,1.0f);
cudaGLMapBufferObject((void**)d_glpointer, pbo);
cudaGLMapBufferObject((void**)d_glpointer, pbo_Right);
//...
// Unmap buffer object
cudaGLUnmapBufferObject(pbo);
glBindBuffer( GL_PIXEL_UNPACK_BUFFER, pbo);
glDrawBuffer(GL_BACK_LEFT);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texturesID[1]);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, image_width, image_height, 0, GL_RGBA, GL_UNSIGNED_BYTE,NULL); // NULL specifies that the image is in memory
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glUniform1i(glGetUniformLocation(shaderProgram, "texLeft"), 1);
// Draw a rectangle from the 2 triangles using 6 indices
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
// Unmap buffer object
cudaGLUnmapBufferObject(pbo_Right);
glBindBuffer( GL_PIXEL_UNPACK_BUFFER, pbo_Right);
// Draw Back Buffers
glDrawBuffer(GL_BACK_RIGHT);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texturesID[0]);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, image_width, image_height, 0, GL_RGBA, GL_UNSIGNED_BYTE,NULL); // NULL specifies that the image is in memory
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glUniform1i(glGetUniformLocation(shaderProgram, "texRight"), 0);
// Draw a rectangle from the 2 triangles using 6 indices
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
// Swap buffers
glutSwapBuffers();
通过使用这段代码,我只能看到最后定义的 outcolor,但我无法找到一种功能方法来根据我使用的缓冲区在 outColor 定义之间进行选择。
我正在使用 Cuda 将图像放入内存中,但问题似乎与此映射无关,因为我总是能够在着色器的外色中看到与最后定义的纹理关联的图像。
如果能帮我解决这个问题,我将不胜感激。
编辑 1: 我向着色器添加了一个计数器,用于验证帧计数 (texCount) 是偶数还是奇数。虽然,我现在没有输出图像。
#version 150 core
in vec3 Color;
in vec2 Texcoord;
out vec4 outColor;
uniform sampler2D texRight;
uniform sampler2D texLeft;
uniform int texCount=1;
void main() {
if (texCount%2){ // if texCount division by two is exact then this is false
outColor = texture(texLeft, Texcoord);
}else{
outColor = texture(texRight, Texcoord);
}
texCount++;
}
最佳答案
我认为以下应该可行。
新的片段着色器:
#version 150 core in vec3 Color;
in vec2 Texcoord;
out vec4 outColor;
uniform sampler2D texIndex;
void main() {
outColor = texture(texIndex, Texcoord);
}
然后将代码中的”texLeft”
和”texRight”
替换为”texIndex”
。
请注意,如果纹理是静态的,则不必在每一帧都上传纹理。理想情况下,您可以将所有只需要执行一次的命令放在一个设置函数中,只有在操作系统通知窗口 reshape 时才执行该函数。
关于c++ - OpenGL 立体 : alternating between left and right textures,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24411070/