glReadPixels is an OpenGL API function to read pixels data from source framebuffer to destination memory buffer. When FBO is supported, the source could be FBO; when PBO is supported, the destination could be PBO.
Questions tagged [glreadpixels]
200 questions
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glReadPixels read "out of frames" area
I draw OpenGL 3200x2000 size textured quads. OpenGLView frame size is set to 940x560. It draws quad as it should. Bun when I try to save it as image (using glReadPixels) and set glReadPixels area from (0,0) to (3200,2000). It creates pixel data…
hockeyman
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How do I check whether a pixel is filled or not on a canvas in OpenGL?
I am trying to detect whether a particular pixel is filled or not in OpenGL in order to implement the flood fill algorithm. So, I searched and found the glreadpixel function but I don't get how I can use this function and whether or not it can solve…
java_doctor_101
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Qt OpenGLFunctions seg fault
I am trying to make a screengrabber using qt and QOpenGLFunctions. My code seg faults on funcs = context->functions(); This code is not really that great or threaded and the timers are not precise at such small intervals but it's more of a proof of…
Will Tangney
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OpenGL: glDrawArrays and glReadPixels in VBO
I am trying to implement a VBO in which I use glDrawArrays to draw a list of triangles and glReadPixels to read the output. The glReadPixels function is throwing a segmentation fault error.
This is the code that initializes and uses the VBO:
void…
jpaguerre
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glReadPixels save to BMP - Color Dirstortion
I'm using OpenGL and PCL_lib right now, And I want to draw a accessory on the background pic.
Here is my output_image on display:
Image source is PCD format(PCL lib), drew by OpenGL
and Here is my code where to save the GL_pic:
char…
Porter Chen
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