Question

在Christer Ericson关于碰撞检测的好书中，他提出了一种加速GPU方法，用于检测凸多边形之间的碰撞，并采用以下算法。

我对OpenGL来说是全新的，我的问题是，给出了两个std::vector点，其中：

struct Point{
    double x,
    double y, 
}

如何将此std::vector<Point>传递给以下函数并在C ++中返回结果？我的向量是凸多边形顺序CCW。

// Initialize depth buffer to far Z (1.0)
glClearDepth(1.0f);
glClear(GL_DEPTH_BUFFER_BIT);
// Disable color buffer writes
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
// Enable depth testing
glEnable(GL_DEPTH_TEST);
// Initialize occlusion queries
Gluint query[1], numSamplesRendered;
glGenQueries(1, query);
// Set pixels to always write depth
glDepthFunc(GL_ALWAYS);
glDepthMask(GL_TRUE);
// Draw front faces of object A
glCullFace(GL_BACK);
RenderObject(A);
// Pass pixels if depth is greater than current depth value
glDepthFunc(GL_GREATER);
// Disable depth buffer updates
glDepthMask(GL_FALSE);
// Render back faces of B with occlusion testing enabled
glBeginQuery(GL_SAMPLES_PASSED, query[0]);
glCullFace(GL_FRONT);
RenderObject(B);
glEndQuery(GL_SAMPLES_PASSED);
// If occlusion test indicates no samples rendered, exit with no collision
glGetQueryObjectuiv(query[0], GL_QUERY_RESULT, &numSamplesRendered);
if (numSamplesRendered == 0) return NO_COLLISION;
// Set pixels to always write depth
glDepthFunc(GL_ALWAYS);
glDepthMask(GL_TRUE);
// Draw front faces of object B
glCullFace(GL_BACK);
RenderObject(B);
// Pass pixels if depth is greater than current depth value
glDepthFunc(GL_GREATER);
// Disable depth buffer updates
glDepthMask(GL_FALSE);
// Render back faces of A with occlusion testing enabled
glBeginQuery(GL_SAMPLES_PASSED, query[0]);
glCullFace(GL_FRONT);
RenderObject(A);
glEndQuery(GL_SAMPLES_PASSED);
// If occlusion test indicates no pixels rendered, exit with no collision
glGetQueryObjectuiv(query[0], GL_QUERY_RESULT, &numSamplesRendered);
if (numSamplesRendered == 0) return NO_COLLISION;
// Objects A and B must be intersecting
return COLLISION;

Answer 1

一种可能的方式：

你需要将std::vector<Point>传递给一个更新对象（A或B或两者）缓冲区（顶点/索引）的函数。
调用将执行遮挡查询并返回结果的函数。在您的情况下可能是布尔值

OpenGL C ++遮挡查询

1 个答案: