如果指定了GL_COLOR_BUFFER_BIT蒙版，glBlitFramebuffer是否复制所有颜色附件? [英] Does glBlitFramebuffer copy all color attachments if GL_COLOR_BUFFER_BIT mask is specified?

问题描述

如果我将像素从一个FBO复制到另一个，并且每个像素都有多个(不一定是相同数量的)颜色附件，并且如果我的遮罩是GL_COLOR_BUFFER_BIT，则哪个颜色附件(GL_COLOR_ATTACHMENT0，GL_COLOR_ATTACHMENT1 ，....，GL_COLOR_ATTACHMENTi)复制吗?他们都是?如果是，如果这些FBO附加了不同数量的颜色缓冲区，该怎么办?

If I am copying pixels from one FBO to another and each of them have multiple (not necessary the same number) of color attachments, and if my mask is GL_COLOR_BUFFER_BIT, which color attachments (GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, ...., GL_COLOR_ATTACHMENTi) does it copy? All of them? If yes, what if these FBOs have different number of color buffers attached to them?

假设有2个以这种方式绑定的FBO:

Assume that there are 2 FBOs that are bound in this way:

glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo1); 
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo2); 

请注意，fbo1具有2个颜色附件，而fbo2具有4个颜色附件.

Note that fbo1 has 2 color attachments and fbo2 has 4 color attachments.

那么在这种情况下glBlitFrameBuffer blit颜色附件如何处理?

So how does the glBlitFrameBuffer blit color attachments in this case?

我在OpenGL文档的任何地方都找不到.

I could not find this anywhere in the OpenGL documentation.

推荐答案

帧缓冲区颜色闪烁操作将 only 从当前glReadBuffer 中读取GL_READ_FRAMEBUFFER，它将 only 写入为GL_DRAW_FRAMEBUFFER指定的glDrawBuffers .因此，它与附件无关.这是关于两个帧缓冲区的读取和绘制缓冲区.

A framebuffer color blitting operation will only read from the current glReadBuffer for the GL_READ_FRAMEBUFFER, and it will only write to the glDrawBuffers specified for the GL_DRAW_FRAMEBUFFER. So it's not about the attachments; it's about the read and draw buffers of the two framebuffers.

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