glBlitFramebuffer, glBlitNamedFramebuffer — copy a block of pixels from one framebuffer object to another
void glBlitFramebuffer(
|
GLint srcX0, |
| GLint srcY0, | |
| GLint srcX1, | |
| GLint srcY1, | |
| GLint dstX0, | |
| GLint dstY0, | |
| GLint dstX1, | |
| GLint dstY1, | |
| GLbitfield mask, | |
GLenum filter); |
void glBlitNamedFramebuffer(
|
GLuint readFramebuffer, |
| GLuint drawFramebuffer, | |
| GLint srcX0, | |
| GLint srcY0, | |
| GLint srcX1, | |
| GLint srcY1, | |
| GLint dstX0, | |
| GLint dstY0, | |
| GLint dstX1, | |
| GLint dstY1, | |
| GLbitfield mask, | |
GLenum filter); |
readFramebuffer
Specifies the name of the source framebuffer object
for glBlitNamedFramebuffer.
drawFramebuffer
Specifies the name of the destination framebuffer object
for glBlitNamedFramebuffer.
srcX0,
srcY0,
srcX1,
srcY1
Specify the bounds of the source rectangle within the read buffer of the read framebuffer.
dstX0,
dstY0,
dstX1,
dstY1
Specify the bounds of the destination rectangle within the write buffer of the write framebuffer.
mask
The bitwise OR of the flags indicating which buffers are to be copied. The allowed flags are
GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT and GL_STENCIL_BUFFER_BIT.
filter
Specifies the interpolation to be applied if the image is stretched. Must be GL_NEAREST or GL_LINEAR.
glBlitFramebuffer and
glBlitNamedFramebuffer transfer a rectangle
of pixel values from one region of a read framebuffer to another
region of a draw framebuffer.
For glBlitFramebuffer, the read and draw
framebuffers are those bound to the
GL_READ_FRAMEBUFFER and
GL_DRAW_FRAMEBUFFER targets respectively.
For glBlitNamedFramebuffer,
readFramebuffer and
drawFramebuffer are the names of the read
and draw framebuffer objects respectively. If
readFramebuffer or
drawFramebuffer is zero, then the default
read or draw framebuffer respectively is used.
mask is the bitwise OR of a number of
values indicating which buffers are to be copied. The values are
GL_COLOR_BUFFER_BIT,
GL_DEPTH_BUFFER_BIT, and
GL_STENCIL_BUFFER_BIT. The pixels
corresponding to these buffers are copied from the source
rectangle bounded by the locations
(srcX0, srcY0) and
(srcX1, srcY1) to
the destination rectangle bounded by the locations
(dstX0, dstY0) and
(dstX1, dstY1).
The lower bounds of the rectangle are inclusive, while the upper
bounds are exclusive.
The actual region taken from the read framebuffer is limited to the intersection of the source buffers being transferred, which may include the color buffer selected by the read buffer, the depth buffer, and/or the stencil buffer depending on mask. The actual region written to the draw framebuffer is limited to the intersection of the destination buffers being written, which may include multiple draw buffers, the depth buffer, and/or the stencil buffer depending on mask. Whether or not the source or destination regions are altered due to these limits, the scaling and offset applied to pixels being transferred is performed as though no such limits were present.
If the sizes of the source and destination rectangles are not
equal, filter specifies the interpolation
method that will be applied to resize the source image , and
must be GL_NEAREST or
GL_LINEAR. GL_LINEAR
is only a valid interpolation method for the color buffer. If
filter is not
GL_NEAREST and mask
includes GL_DEPTH_BUFFER_BIT or
GL_STENCIL_BUFFER_BIT, no data is
transferred and a GL_INVALID_OPERATION
error is generated.
If filter is
GL_LINEAR and the source rectangle would
require sampling outside the bounds of the source framebuffer,
values are read as if the GL_CLAMP_TO_EDGE
texture wrapping mode were applied.
When the color buffer is transferred, values are taken from the read buffer of the specified read framebuffer and written to each of the draw buffers of the specified draw framebuffer.
If the source and destination rectangles overlap or are the same, and the read and draw buffers are the same, the result of the operation is undefined.
GL_INVALID_OPERATION is generated by
BlitNamedFramebuffer if
readFramebuffer or
drawFramebuffer is not zero or the name
of an existing framebuffer object.
GL_INVALID_OPERATION is generated if
mask contains any of the
GL_DEPTH_BUFFER_BIT or
GL_STENCIL_BUFFER_BIT and
filter is not
GL_NEAREST.
GL_INVALID_OPERATION is generated if
mask contains
GL_COLOR_BUFFER_BIT and any of the
following conditions hold:
The read buffer contains fixed-point or floating-point values and any draw buffer contains neither fixed-point nor floating-point values.
The read buffer contains unsigned integer values and any draw buffer does not contain unsigned integer values.
The read buffer contains signed integer values and any draw buffer does not contain signed integer values.
GL_INVALID_OPERATION is generated if
mask contains
GL_DEPTH_BUFFER_BIT or
GL_STENCIL_BUFFER_BIT and the source and
destination depth and stencil formats do not match.
GL_INVALID_OPERATION is generated if
filter is GL_LINEAR
and the read buffer contains integer data.
GL_INVALID_OPERATION is generated if the
effective value of GL_SAMPLES for the read
and draw framebuffers is not identical.
GL_INVALID_OPERATION is generated if the
value of GL_SAMPLE_BUFFERS for both read
and draw buffers is greater than zero and the dimensions of the
source and destination rectangles is not identical.
GL_INVALID_FRAMEBUFFER_OPERATION is
generated if the specified read and draw framebuffers are not
framebuffer complete.
| 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 |
glBlitFramebuffer
|
- | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
glBlitNamedFramebuffer
|
- | - | - | - | - | - | - | - | - | - | - | ✔ |
glReadPixels glCheckFramebufferStatus, glGenFramebuffers glBindFramebuffer glDeleteFramebuffers
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/.