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View Full Version : Texture Mapping Vs glDrawPixels()



ashishagg
10-31-2001, 07:15 PM
I loaded images first using glDrawPixels() and then using Texture Mapping. When I ran my program on a PC with WildCat4200, fps (frame per second) for Texture mapping was 60 fps while for glDrawPixels() was 40fps. But when I ran the same programs on a PC without wildcat card, fps for TM was same while fps for glDrawPixels() reduced to 6fps.

My Questions:

1. why there is no change in the fps for Texture mapping while there is a drastic change in fps for glDrawPixels() while using graphics card.

2. What makes Texture Mapping superior to glDrawPixels( Is that the case always or sometimes glDrawPixels is beter than Texture mapping)

Please reply me ASAP. I am not able to get the exact answer for my problems.

Thanks in advance

Ashish

Omaha
10-31-2001, 07:24 PM
DrawPixels has to get direct access to the color buffer, which is time expensive.

Texture mapping just puts the image through the appropriate transformations and the regular pipeline.

Gavin
10-31-2001, 11:59 PM
Texture mapping is hardware accelerated and drawpixels is not.