Objective c 无法捕捉OpenGL和顶点数组对象的错误

我很难发现这个OpenGL实现的错误。当我运行程序时，我得到的唯一东西就是一个黑屏。我应该看到一个立方体。我没有犯任何错误。我怀疑罪犯可能会与VAO发生关系：

// draws the view
-(void)drawRect:(NSRect)dirtyRect
{
// clear the viewport
glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

shaderProgramID = [self loadShaders];

// get uniform locations
uniformLocations[0] = glGetUniformLocation(shaderProgramID, "rotationX");
uniformLocations[1] = glGetUniformLocation(shaderProgramID, "rotationY");
uniformLocations[2] = glGetUniformLocation(shaderProgramID, "rotationZ");
uniformLocations[3] = glGetUniformLocation(shaderProgramID, "translation");
uniformLocations[4] = glGetUniformLocation(shaderProgramID, "projection");

// use this program
glUseProgram(shaderProgramID);

// create VAO
glGenVertexArraysAPPLE(1, &vao);
glBindVertexArrayAPPLE(vao);
glGenBuffers(3, vbo);

// bind and copy data for vertex position data
glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubePositionData), cubePositionData, GL_STATIC_DRAW);
glVertexAttribPointer(TCV_VERTEX_POS_INDEX, TCV_NUM_POS_COMPONENTS, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(TCV_VERTEX_POS_INDEX);

// bind and copy data for vertex color data
glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeColorData), cubeColorData, GL_STATIC_DRAW);
glVertexAttribPointer(TCV_VERTEX_COLOR_INDEX, TCV_NUM_COLOR_COMPONENTS, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(TCV_VERTEX_COLOR_INDEX);

// bind and copy data for vertex indices data
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vbo[2]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(cubeIndices), cubeIndices, GL_STATIC_DRAW);
glVertexAttribPointer(TCV_VERTEX_INDICES_INDEX, TCV_NUM_INDEX_ARRAY_COMPONENTS, GL_UNSIGNED_BYTE, GL_FALSE, 0, 0);
glEnableVertexAttribArray(TCV_VERTEX_INDICES_INDEX);

// load uniform data into shader program
glUniformMatrix4fv(uniformLocations[0], 1, GL_FALSE, rotationMatX);
glUniformMatrix4fv(uniformLocations[1], 1, GL_FALSE, rotationMatY);
glUniformMatrix4fv(uniformLocations[2], 1, GL_FALSE, rotationMatZ);
glUniformMatrix4fv(uniformLocations[3], 1, GL_FALSE, translationMat);
glUniformMatrix4fv(uniformLocations[4], 1, GL_FALSE, projectionMat);

// tell OGL to draw the cube, in this order
glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_BYTE, cubeIndices);

// unbind VAO
glBindVertexArrayAPPLE(0);

// no longer using program
glUseProgram(0);

// flush buffer
glFlush();
[[self openGLContext] flushBuffer];
}

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我的OpenGL实验也有类似的问题。我还为顶点位置和顶点颜色数据使用了单独的缓冲区对象。我相信只有一个GL_数组_缓冲区可以绑定到顶点数组对象。因此，将所有数据放入一个组合缓冲区，然后将带有偏移量的属性指针设置到该缓冲区中

您的VBO/VAO设置应类似于：

glGenVertexArrays(1, &vertexArray);
glBindVertexArray(vertexArray);

glGenBuffers(1,&vertexBuffer);
glBindBuffer(vertexBuffer);
glBindBufferData(GL_ARRAY_BUFFER, sizeof(cubePositionAndColorData), cubePositionAndColorData, GL_STATIC_DRAW);

glVertexAttribPointer(kPositionAttribute, NUM_VERTEX_COMPONENTS, GL_FLOAT, GL_FALSE, 0, 0);
// colorStartingIndex is probably just NUM_VERTEX_COMPONENTS*sizeof(GLfloat)
glVertexAttribPointer(kColorAttribute, NUM_COLOR_COMPONENTS, GL_FLOAT, GL_FALSE, 0, (void *)colorStartingIndex);

glEnableVertexAttribArray(kPositionAttribute);
glEnableVertexAttribArray(kColorAttribute);

glGenBuffers(1,&indexBuffer);
glBindBuffer(indexBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(cubeIndices), cubeIndices, GL_STATIC_DRAW);

glBindVertexArray(0);

然后，在

-drawRect:

函数中，您可以使用该程序，设置制服并调用

glDrawElements（）

：

另外两项值得注意：

我建议将所有缓冲区初始化移出

-drawRect:

方法，因为每次重新绘制视图时都会调用它。这意味着您正在将所有数据重新复制到每个

-drawRect:

上的OpenGL服务器

如果您使用的是OSX的最新版本，则应该考虑使用OpenGL的最新版本（<代码> OpenGL/GL3.H）。

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这听起来像是一个坏记录，但您是否在每次调用gl后都检查了glError？我会通过OpenGL Profiler运行此命令，以检查渲染时的所有状态是否正确，并且没有出现错误：“/Developer/Applications/Graphics Tools/OpenGL Profiler”

glUseProgram(shaderProgramID);

// do the necessary uniform configuration
glUniformMatrix4fv(...)

glBindVertexArray(vertexArray);
glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_BYTE, 0);

glBindVertexArray(0);

glUseProgram(0);