如何使用深度纹理与模具，OpenGL ES 3.0

Question

我有一个应用程序，我想使用模具蒙版渲染纹理深度。我尝试GL_DEPTH_STENCIL_OES：

创建质地：

glGenFramebuffers(1, fbo); 
glBindFramebuffer(GL_FRAMEBUFFER, *fbo); 

glGenTextures(1, depthTexture); 
glBindTexture(GL_TEXTURE_2D, *depthTexture); 
// using combined format: depth + stencil 
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_STENCIL_OES, w, h, 0, GL_DEPTH_STENCIL_OES, GL_UNSIGNED_INT_24_8_OES, NULL); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE); 

// attaching both depth and stencil 
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, *depthTexture, 0); 
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_TEXTURE_2D, *depthTexture, 0); 

// No color output in the bound framebuffer, only depth. 
GLenum drawbuffers[] = { GL_NONE }; 
glDrawBuffers(1, drawbuffers); 

GL_CHECK(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE); 

创建阴影贴图镂空掩膜：

glBindFramebuffer(GL_FRAMEBUFFER, *fbo); 
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 

glEnable(GL_STENCIL_TEST); 
glStencilFunc(GL_EQUAL, 1, 0xFF); // Pass test if stencil value is 1 
glStencilMask(0x00); // Don't write anything to stencil buffer 
glDepthMask(GL_TRUE); // Write to depth buffer 

drawObjects(); 

当代码为：

// bind to depth fbo 
glBindFramebuffer(GL_FRAMEBUFFER, *fbo); 

glEnable(GL_STENCIL_TEST); 
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE); 
glClear(GL_STENCIL_BUFFER_BIT); 

// write to stencil when objects are rendered 
glStencilFunc(GL_ALWAYS, 1, 0xFF); 
glStencilMask(0xFF); 

drawVisibleObjects(); 

与模板掩模深度渲染执行，屏幕是黑色的。这是意想不到的，因为我不会将深度渲染到默认帧缓冲区，而是渲染到纹理。由于模板值存储在纹理中，我必须以不同的方式使用它们吗？

使用组合深度 - 模板纹理GL_DEPTH_STENCIL_OES时，使用模板附件的正确方法是什么？

Answer 1

模板值是您正在渲染的帧缓冲区的属性。如果您想在FBO0中使用模板掩模，那么您需要在FBO0中请求模板（并在渲染到FBO0时填充掩模等）。