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JoeZ

setpixel Direct Draw or Direct3D

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Hi: I just wonder if you just set pixel by pixel on the screen which one is faster DirectDraw or Direct3D? Thanks

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Are we comparing DDraw7 with D3D8?
In case, I think that it should be quite hard to make a pixelput faster than writing directly to memory as in DDraw7!
On the other hand, if you are using D3D8 you can get images drawn in different rotations and get it hardware accelereated if it's supported by the graphics card!

Cheers,

Johan Ersvik

[edited by - Ersvik on August 16, 2002 11:39:06 AM]

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Hi

You can also lock the Video Memory and write to it directly in D3D8, because the frontbuffer and the backbuffers are just D3DImageSurfaces that are quite similar to DirectDraw surfaces.

CU Melo

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Vote Schröder!

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melo, however locking such surfaces in d3d8 has a larger performence cost sine the pipeline is optimized for 3d rendering not per pixel access, especially to the back buffer. access to the front buffer is VERY limited. back buffer is pretty limited as well. also there are stalls and trasintion of going from 2d to 3d paths in the driver. in fact many cards prohibit mixed 2d and 3d operations (ie 2d ops within begin/end scene).

JoeZ, please ignore melo. he obviously is used to d3d7 which allowed directdraw like access to buffers (though the penetly was still there).

this is a silly question.

you want per pixel access use directdraw7. its the fastest way since you are literally writing directly to vram.

you want such a thing in d3d8? draw to a dynamic texture and render it as a quad.

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