Vertex Buffer... 2D terrain?

jacksaccountongamedev · 2003-10-10T10:15:49

Hi. My game uses D3D 8.1 and is 2D-side-view (800x600x16), where I render the ground as a bunch of triangles, in a way similar to that seen in such games as Soldat and Elasto-mania. Now, each triangle is stored as a linked-list consists of three vertecies (obviously), and can have one of four textures. Previously, I have been going through the linked-list every frame, using DrawPrimativeUP to render the ground. I am also rendering 2 tiled-backdrops using DrawPrimativeUP, one a cloud-texture, the other a 94% transparent texture with a few drops of rain on it. I also draw the game objects, which are rarely bigger that 32x32. This is s l o w. When I render the terrain, objects and one backdrop, I get acceptable framerates. But as soon as I go for the second backdrop, I get about 18 fps. This sucks. I figure this is because I am using DrawPrimativeUP instead of creating vertex buffers and using DrawPrimative. Vertex buffers for each backdrop should be easy enough. My questions concern the rendering of the terrain. So far, I render my triangles at their co-ordiantes, - viewx,viewy: variables describing the current view of the game word. 1) Would I need a vertex buffer of triangles for each of the four textures ie triangles of texture a go into vb a etc? 2) Do I need to clear my vertex buffer (for the triangles) every frame, and then go through my linked list and copy the vertex co-ordiantes - viewx/viewy, or is there some way I can create a static vertex buffer, then use matricies (I dont know what they are) or something to alter the view of the game world (this would be better because I wouldnt have to reload the vb every frame)?. Note that the terrain never changes, other than to reflect the current viewx/viewy position. 3) If I do clear vb, reload the triangles based on view co-ordinates etc then how would I do this? Ie, how would I use memcpy to go through a linked list, adding in more data to the vb as I go? 4) Am I right that it is DrawPrimativeUP that is killing my framerate? Thanks in advance to anyone that can help.