Initializing DDraw

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Original post by robinei
I intend use ddraw to access the framebuffer directly, for the purpose of trying to write a simple triangle rasterizer, so it must be in system memory.

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(Ignore this point if you don''t use D3D).
- You can do that in Direct3D if you want. Just add the D3DPRESENT_LOCKABLE_BACKBUFFER flag to your presentationParameters.Flags, and then lock the back-buffer )with the D3DLOCK_NOSYSLOCK flag) and do all the software rendering you''d like.

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How should one initialize ddraw for such a purpose? The usual primary/backbuffer scheme(or is that intended for fast hardware blits)?

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The usual primary/backbuffer scheme. If you draw directly to the front-buffer, then the user''s going to see horrible flickering and tearing, as you render your scene step-by-step.

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If so, which surface is then in fact in system memory, and should thus be used?

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Just lock the back-buffer, write to it, unlock, flip, and you''re done.

Muhammad Haggag
Bitwise account: MHaggag -

Can I assume that the pitch of the backbuffer is equal to the screen width?

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Original post by robinei
Can I assume that the pitch of the backbuffer is equal to the screen width?

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No. You can''t assume the pitch of *any* surface that the card uses is the same as the width.

Muhammad Haggag
Bitwise account: MHaggag -