Qt的bindTexture有什么魔力？

Question

我正在使用Qt5和QGLWidget类来呈现像素的实时流。我遇到了一些性能问题，并希望设置一个像素缓冲区来执行异步数据传输。

我想绑定纹理旧式的方式，但它呈现为空白。当我回到我的Qt5代码时，一切正常。

有没有人知道如何让标准的OpenGL版本工作？

工作

void glStream::reserveTextures() 
{ 
    displayBuff = (GLubyte*) calloc(numGLFrames*widthGL*heightGL, 
    sizeof(GLubyte)); 

    QImage mySurface(&displayBuff[displayStart],widthGL,heightGL, 
    QImage::Format_Indexed8); 
    textures[0]=bindTexture(mySurface,GL_TEXTURE_2D,GL_LUMINANCE); 

    glBindTexture(GL_TEXTURE_2D,0); 
    glECheck();//no errors 
} 

不工作

void glStream::reserveTextures() 
{ 
    displayBuff = (GLubyte*) calloc(numGLFrames*widthGL*heightGL,sizeof(GLubyte)); 

    glGenTextures(1,&textures[0]); 
    glBindTexture(GL_TEXTURE_2D,textures[0]); 
    glTexImage2D(GL_TEXTURE_2D,0,GL_LUMINANCE,widthGL,heightGL,0,GL_LUMINANCE, 
    GL_UNSIGNED_BYTE,&displayBuff[displayStart]); 

    glBindTexture(GL_TEXTURE_2D,0); 
    glECheck();//no errors 
} 

更新功能

glECheck(); 
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
glLoadIdentity(); 
program1.bind(); 
program1.setUniformValue("texture", 0); 
program1.enableAttributeArray(vertexAttr1); 
program1.enableAttributeArray(vertexTexr1); 
program1.setAttributeArray(vertexAttr1, vertices.constData()); 
program1.setAttributeArray(vertexTexr1, texCoords.constData()); 
glBindTexture(GL_TEXTURE_2D, textures[0]); 
glECheck(); 
glDrawArrays(GL_TRIANGLES, 0, vertices.size()); 
glBindTexture(GL_TEXTURE_2D,0); 
program1.disableAttributeArray(vertexTexr1); 
program1.disableAttributeArray(vertexAttr1); 
program1.release(); 
glECheck(); 

着色

QGLShader *fshader1 = new QGLShader(QGLShader::Fragment, this); 
    const char *fsrc1 = 
     "uniform sampler2D texture;\n" 
     "varying mediump vec4 texc;\n" 
     "void main(void)\n" 
     "{\n" 
     " gl_FragColor = texture2D(texture, texc.st);\n" 
     "}\n"; 

    fshader1->compileSourceCode(fsrc1); 
    program1.addShader(fshader1); 

Answer 1

这样看来，你需要能够显示纹理其他一些设置。

void glStream::reserveTextures() 
{ 
    displayBuff = (GLubyte*) calloc(numGLFrames*widthGL*heightGL,sizeof(GLubyte)); 

    glGenTextures(1,&textures[0]); 
    glBindTexture(GL_TEXTURE_2D,textures[0]); 
    glTexImage2D(GL_TEXTURE_2D,0,GL_LUMINANCE,widthGL,heightGL,0,GL_LUMINANCE, 
    GL_UNSIGNED_BYTE,&displayBuff[displayStart]); 

    //This is the magic inside Qt5's implementation 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); 

    glBindTexture(GL_TEXTURE_2D,0); 
    glECheck();//no errors 
}