Ok, i have conducted a fairly, erm, fair test of the speed difference between copyrect + 256 (force texture to VRAM flag) and the Render To Texture function found within the fastlibs library.
My results are all pretty conclusive at a number of different iterations of copyrect and rendertotexture calls per loop.
I found that render to texture is faster by up to 50%. This was conducted using a 512 x 512 texture. The cameraviewport was resized to the texture size in both tests, to ensure the same dimension of pixels was being copied.
However, when switching to smaller sized textures, 256 128 64, the difference was practically not noticable. I'm talking 1 fps over 50 copyrects.
So, for the results. My scene in 20 sphere's, with segment level of 3. A cube to texture my screen renders on. And a texture for the sphere. My rig handles this no problem, at 1700 fps+.
Code used for this test.
I've hardcoded the resolution. This won't run unless you have the fast lib.dll and include file, which i can't give you, because they are copyrighted :o)
If there is anything i have missed i will try and address them.
To some up, copyrect, on my rig anyway, only really pulls up the performance if the texture being rendered to, is over a certain size, in this case, anything over 256x256. It must be to do with the behind the scenes work of copyrect and rendertotexture taking longer than the actual copy itself.
My results are all pretty conclusive at a number of different iterations of copyrect and rendertotexture calls per loop.
I found that render to texture is faster by up to 50%. This was conducted using a 512 x 512 texture. The cameraviewport was resized to the texture size in both tests, to ensure the same dimension of pixels was being copied.
However, when switching to smaller sized textures, 256 128 64, the difference was practically not noticable. I'm talking 1 fps over 50 copyrects.
So, for the results. My scene in 20 sphere's, with segment level of 3. A cube to texture my screen renders on. And a texture for the sphere. My rig handles this no problem, at 1700 fps+.
Code used for this test.
Include "FastExt.bb" Graphics3D 1024,768 InitExt SetBuffer BackBuffer() Global camera = CreateCamera() Global light = CreateLight() Global ts = 512 ; create two textures, one with the render to texture flag applied. Both must have 256 flag applied. Global texRender2Tex = CreateTexture(ts,ts, 1 + 2 + 256 + FE_ExSIZE + FE_RENDER );+ FE_ZRENDER) Global texRenderNormal = CreateTexture(ts,ts, 1 + 2 + 256) Global sphere_texture = CreateTexture(64,64) SetBuffer TextureBuffer(sphere_texture) For tloop = 0 To 31 Color 10+tloop*3 , 100+tloop*4 , 100+tloop*3 Rect tloop , tloop , (32-tloop)*2 , (32-tloop)*2 Next SetBuffer BackBuffer() Dim sphere(20) For eloop = 0 To 20 sphere(eloop) = CreateSphere(3) PositionEntity sphere(eloop),Rnd(-10,10),Rnd(-10,10),Rnd(10,20) Next Global cube = CreateCube() EntityTexture cube,texRenderNormal PositionEntity cube,0,-0.5,2 ScaleEntity cube,0.3,0.3,0.3 Global timer, frame, time, fps, mode While Not KeyHit(1) TurnEntity cube,0,1,0 If KeyHit(57) Then mode = 1-mode retexture() End If If mode = 0 Then render_to_texture_fake() ElseIf mode = 1 Then render_to_texture_real() End If If MilliSecs()<timer+1000 Then frame=frame+1 Else fps=frame frame=0 timer=MilliSecs() End If UpdateWorld RenderWorld Text 0,0," SPACE to toggle mode" If mode = 0 Then Text 0,10," COPYRECT method" Else Text 0,10," RENDER TO TEXTURE method" End If Text 0,20,"fps="+fps Flip 0 Wend Function retexture() Local texture If mode = 0 Then texture = texRenderNormal Else texture = texRender2Tex End If EntityTexture cube,texture End Function Function render_to_texture_fake() For loop = 0 To 50 CameraViewport camera,0,0,ts,ts RenderWorld CopyRect 0,0,ts,ts,0,0,BackBuffer(),TextureBuffer(texRenderNormal) Next CameraViewport camera,0,0,1024,768 End Function Function render_to_texture_real() For loop = 0 To 50 CameraViewport camera,0,0,ts,ts SetBuffer TextureBuffer(texRender2Tex) RenderWorld SetBuffer BackBuffer() Next CameraViewport camera,0,0,1024,768 End Function
I've hardcoded the resolution. This won't run unless you have the fast lib.dll and include file, which i can't give you, because they are copyrighted :o)
If there is anything i have missed i will try and address them.
To some up, copyrect, on my rig anyway, only really pulls up the performance if the texture being rendered to, is over a certain size, in this case, anything over 256x256. It must be to do with the behind the scenes work of copyrect and rendertotexture taking longer than the actual copy itself.