opengl API glCheckFramebufferStatus详解

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妙为 2022-07-06 13:27:31 博主文章分类：图形图像三维仿真游戏开发 ©著作权

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Name

glCheckFramebufferStatus, glCheckNamedFramebufferStatus — check the completeness status of a framebuffer

C Specification

`GLenum glCheckFramebufferStatus(`	GLenum target`)`;

`GLenum glCheckNamedFramebufferStatus(`	GLuint framebuffer,
	GLenum target`)`;

Parameters

target

Specify the target to which the framebuffer is bound for glCheckFramebufferStatus, and the target against which framebuffer completeness of framebuffer is checked for glCheckNamedFramebufferStatus.

framebuffer

Specifies the name of the framebuffer object for glCheckNamedFramebufferStatus

Description

glCheckFramebufferStatus and glCheckNamedFramebufferStatus return the completeness status of a framebuffer object when treated as a read or draw framebuffer, depending on the value of target.

For glCheckFramebufferStatus, the framebuffer checked is that bound to target, which must be GL_DRAW_FRAMEBUFFER, GL_READ_FRAMEBUFFER or GL_FRAMEBUFFER. GL_FRAMEBUFFER is equivalent to GL_DRAW_FRAMEBUFFER.

For glCheckNamedFramebufferStatus, framebuffer is zero or the name of the framebuffer object to check. If framebuffer is zero, then the status of the default read or draw framebuffer, as determined by target, is returned.

The return value is GL_FRAMEBUFFER_COMPLETE if the specified framebuffer is complete. Otherwise, the return value is determined as follows:

GL_FRAMEBUFFER_UNDEFINED is returned if the specified framebuffer is the default read or draw framebuffer, but the default framebuffer does not exist.
GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT is returned if any of the framebuffer attachment points are framebuffer incomplete.
GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT is returned if the framebuffer does not have at least one image attached to it.
GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER is returned if the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE is GL_NONE for any color attachment point(s) named by GL_DRAW_BUFFERi.
GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER is returned if GL_READ_BUFFER is not GL_NONE and the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE is GL_NONE for the color attachment point named by GL_READ_BUFFER.
GL_FRAMEBUFFER_UNSUPPORTED is returned if the combination of internal formats of the attached images violates an implementation-dependent set of restrictions.
GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE is returned if the value of GL_RENDERBUFFER_SAMPLES is not the same for all attached renderbuffers; if the value of GL_TEXTURE_SAMPLES is the not same for all attached textures; or, if the attached images are a mix of renderbuffers and textures, the value of GL_RENDERBUFFER_SAMPLES does not match the value of GL_TEXTURE_SAMPLES.
GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE is also returned if the value of GL_TEXTURE_FIXED_SAMPLE_LOCATIONS is not the same for all attached textures; or, if the attached images are a mix of renderbuffers and textures, the value of GL_TEXTURE_FIXED_SAMPLE_LOCATIONS is not GL_TRUE for all attached textures.
GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS is returned if any framebuffer attachment is layered, and any populated attachment is not layered, or if all populated color attachments are not from textures of the same target.

Additionally, if an error occurs, zero is returned.

Errors

GL_INVALID_ENUM is generated if target is not GL_DRAW_FRAMEBUFFER, GL_READ_FRAMEBUFFER or GL_FRAMEBUFFER.

GL_INVALID_OPERATION is generated by glCheckNamedFramebufferStatus if framebuffer

Version Support

												OpenGL Version
Function / Feature Name	2.0	2.1	3.0	3.1	3.2	3.3	4.0	4.1	4.2	4.3	4.4	4.5
`glCheckFramebufferStatus`	-	-	✔	✔	✔	✔	✔	✔	✔	✔	✔	✔
`glCheckNamedFramebufferStatus`	-	-	-	-	-	-	-	-	-	-	-	✔

Copyright

Copyright © 2010-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.

中文翻译：

检查帧缓冲区的使用操作类型是否已准备好。

FBO完整性的判别法则如下：

与FBO挂接的二维数组对象的长度和宽度必须不能为0。
如果一个二维数组对象被挂接到FBO的颜色缓冲区挂接点时，二维数组必须具有内部颜色格式(GL_RGBA, GL_DEPTH_COMPONENT, GL_LUMINANCE等)。
如果一个二维数组对象被挂接到FBO的深度缓冲区挂接点时，二维数组必须具有内部深度格式(GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT24_EXT等)。
如果一个二维数组对象被挂接到FBO的模板缓冲区挂接点时，二维数组必须具有内部模板格式(GL_STENCIL_INDEX, GL_STENCIL_INDEX8_EXT等)。
FBO至少挂接有一个二维数组缓冲区对象。
同一个FBO上挂接的二维数组对象必须拥有相同的长度和宽度。
所有的颜色缓冲区挂接点上挂接的二维数组对象必须具有相同的内部格式。

GLenum glCheckFramebufferStatus( GLenum target);

target

Specify the target to which the framebuffer is bound for glCheckFramebufferStatus, and the target against which framebuffer completeness of framebuffer is checked for glCheckNamedFramebufferStatus.

指定帧缓冲区的使用操作类型。可以取GL_DRAW_FRAMEBUFFER, GL_READ_FRAMEBUFFER 和GL_FRAMEBUFFER.之一 GL_FRAMEBUFFER等价于GL_DRAW_FRAMEBUFFER.

返回值：

GL_FRAMEBUFFER_COMPLETE：帧缓冲区的使用操作类型准备好了

GL_FRAMEBUFFER_UNDEFINED：帧缓冲区是默认帧缓冲区，并且默认帧缓冲区不存在

GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT：帧缓冲区的所有挂载点都没有准备好

GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT：帧缓冲区一张图像也没有挂载