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Member Since 25 Oct 2010
Offline Last Active Jul 11 2014 06:22 AM

Topics I've Started

Blocked SwapBuffers

06 February 2014 - 07:17 AM

Hi All

In some cases aglSwapBuffers doesn't update screen. However when mouse pressed in window, it's updated without any re-render.
No luck with caatch update moment/call in debugger. For example if stop on breakpoint - screen is already updated, but if go step by step - not updated yet. In past a bit similar prob was solved with set AGL_SWAP_INTERVAL = 1, but now it has no effect.

I realize agl framework is totally obsolete but we need a refactoring to get rid of it, that is what I'm doing now.

Any idea?




Just Hilite cell with Quartz

27 January 2014 - 12:01 PM

Hi All,
I'm porting old app and replacing old QuickDraw drawing with Quartz one. There are a lot of "hilites" in old code that typically replaces background color with selection color inside cell/rectangle. How to make same with Quartz?
What I tried is:
1) Use cache CGBitmapContextRef. It works but now app took ~300Mb of RAM (vs 50 before). From what I read I've figured out - it's conceptual mistake, triple-buffer.
2) Ok, so I've switched to Quatz "blend modes". There are a lot of them, but no one does what I need. If I change background, so text's and other colors are changed too.
I can't find a way to replace a color selectively.
Any suggestion is very appreciated.

Sphere/Cylinder mapping with OpenGL

29 March 2013 - 05:27 AM

Hi All
I need spherical/cylindrical map for arbitrary objects (not a reflection mapping). Actually I'm calculating UV manually. If a polygon crosses UV seam or pole, then I split it into several new polygons. It works but it's a big piece of code that makes app much slower. Are there better ways with OpenGL?

VBO slow

18 March 2013 - 12:10 PM

Hi All
I've implemented VBO but got a slower render (only 1 fps vs 3 fps without VBO).
After series of experiments I've found the problem is caused by using GL_DOUBLE for at least one chunk (vertices, normals, UVs etc). With GL_FLOAT for everything my results are good: 17 fps with VBO. So my questions are:
- is a low speed normal/expected with GL_DOUBLE ?
- how can I make VBO faster yet?
My setings are:
OpenGL Vendor: ATI Technologies Inc.
OpenGL Renderer: ATI Radeon HD 2600 OpenGL Engine
OpenGL Version: 2.1 ATI-1.6.36
Vertices 756,780
Polygons 1,169,235
Objects 150
VBO buffers: 150 * 2 = 300 
Using glDrawElements
Shading: gourand
Total VBO RAM: 42,513.104

Missed Line

12 March 2013 - 07:01 AM

Hi All
In glOrtho I'm drawing a line with  2 points (x, y, z)
(434, 500, 400)
(1190, 500, -1152)
But the line is not displayed. However if I change z in debugger (from -1152 to 400), then all is Ok, a horizontal line appears. Same results with glDrawArrays, glDrawArrays and just glBegin/glEnd
Any advice?