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我跟着this tutorial和我目前正在嘗試創建一個類來繪製立方體。該類在一個名爲setup的函數中填充緩衝區,並在一個名爲draw的函數中繪製它們。製作一個iPhone立方體課
但沒有錯誤,但屏幕上沒有顯示任何內容。
我的問題基本上是如何去做一個我可以渲染立方體的類。
使用Xcode 4.2,Opengl和Objective-C。
[編輯]
-(void)SetShader:(GLuint)InShader
{
glUseProgram(InShader);
_positionSlot = glGetAttribLocation(InShader, "Position");
_colorSlot = glGetAttribLocation(InShader, "SourceColor");
glEnableVertexAttribArray(_positionSlot);
glEnableVertexAttribArray(_colorSlot);
_projectionUniform = glGetUniformLocation(InShader, "Projection");
_modelViewUniform = glGetUniformLocation(InShader, "Modelview");
_texCoordSlot = glGetAttribLocation(InShader, "TexCoordIn");
glEnableVertexAttribArray(_texCoordSlot);
_textureUniform = glGetUniformLocation(InShader, "Texture");
}
-(void)SetupVBO
{
GLuint vertexBuffer;
glGenBuffers(1, &vertexBuffer);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(CubeVertices), CubeVertices, GL_STATIC_DRAW);
GLuint indexBuffer;
glGenBuffers(1, &indexBuffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(CubeIndices), CubeIndices, GL_STATIC_DRAW);
}
-(void)draw
{
glVertexAttribPointer(_positionSlot, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0);
glVertexAttribPointer(_colorSlot, 4, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*) (sizeof(float) * 3));
glVertexAttribPointer(_texCoordSlot, 2, GL_FLOAT, GL_FALSE,
sizeof(Vertex), (GLvoid*) (sizeof(float) * 7));
glDrawElements(GL_TRIANGLES, sizeof(CubeIndices)/sizeof(CubeIndices[0]), GL_UNSIGNED_BYTE, 0);
}
-(void)render:(CADisplayLink*)displayLink
{
glClearColor(0, 0, 0.2, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);
CC3GLMatrix *projection = [CC3GLMatrix matrix];
float h = 4.0f * self.frame.size.height/self.frame.size.width;
[projection populateFromFrustumLeft:-2 andRight:2 andBottom:-h/2 andTop:h/2 andNear:4 andFar:10];
glUniformMatrix4fv(_projectionUniform, 1, 0, projection.glMatrix);
CC3GLMatrix *modelView = [CC3GLMatrix matrix];
[modelView populateFromTranslation:CC3VectorMake(0, 0, -7)];
[modelView translateBy:CC3VectorMake(0,5,0)];
glUniformMatrix4fv(_modelViewUniform, 1, 0, modelView.glMatrix);
glViewport(0, 0, self.frame.size.width, self.frame.size.height);
[m_cube draw];
[_context presentRenderbuffer:GL_RENDERBUFFER];
}
請張貼您的代碼。 –
問題很模糊。遵循教程沒有任何改變對你有用嗎?如果是這樣,你做了什麼改變,沒有工作?一般來說,OpenGL什麼都不抽,這是因爲OpenGL狀態機設置很奇怪。如果你發佈了一些代碼,說明你如何設置,特別是對'glViewport()','glOrtho()','gluPerspective()'和/或'glFrustum()'的調用,這將會有所幫助。 – user1118321
我已經發布了一些相關的代碼 – Dave