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目前我正在使用openGLES在简单的游戏应用程序中工作，使用GL_Lines模式画一条线并且工作正常，我想使用GL_TRIANGLE_STRIP画一条线，是否可以使用GL_TRIANGLE_STRIP画一条线？

提前致谢

我试过源代码：

  glClearColor(0.65f, 0.65f, 0.65f, 1.0f); //Background color changes, its like Red,Green,Blue,Alpha color. 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    [self.effect prepareToDraw];


        const GLfloat line[] = 
        {
            0.0f, 0.5f,
            0.0f, -1.5f,
           0.0f,-1.5f,
        };

        // Create buffer object array
        GLuint bufferObjectNameArray;

        // Have OpenGL generate a buffer name and store the buffer object array 
        glGenBuffers(1, &bufferObjectNameArray);

        // Bind the buffer object array to the GL_ARRAY_BUFFER target buffer  
        glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNameArray); 

        // Send the line data over to the target buffer
        glBufferData(
                     GL_ARRAY_BUFFER,   // the target buffer 
                     sizeof(line),      // the number of bytes to put into the buffer
                     line,              // a pointer to the data being copied 
                     GL_STATIC_DRAW);   // the usage pattern of the data 

        // Enable vertex data to be fed down the graphics pipeline to be drawn
        glEnableVertexAttribArray(GLKVertexAttribPosition); 

        // Specify how the GPU looks up the data 
        glVertexAttribPointer(
                              GLKVertexAttribPosition, // the currently bound buffer holds the data 
                              2,                       // number of coordinates per vertex 
                              GL_FLOAT,                // the data type of each component 
                              GL_FALSE,                // can the data be scaled 
                              2*4,                    // how many bytes per vertex (2 floats per vertex)
                              NULL);                   // offset to the first coordinate, in this case 0 
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 3);
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1 回答 1

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您需要复制线的每个顶点并对其进行偏移：

const GLfloat line[] = 
    {
        -1.0f, 0.5f, 1.0f, 0.5f,//0.0f, 0.5f,
        -1.0f, 0.5f, 1.0f, 1.5f,//0.0f, -1.5f,
    };
...
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

它只是用于具有预定义线方向的线。否则，您需要将偏移方向计算为垂直于线的方向。

于 2012-04-24T13:14:41.463 回答