Decal on texture
Blitz3D Forums/Blitz3D Programming/Decal on texture
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| Hi, Is there a way to use the WritePixel command to paint a preset texture onto another texture, like a stamp? |
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Try this code. You just need to call:ApplyDecal source_texture , dest_texture [,r,g,b]Both 'texture' parameters should point to a loaded texture. The source texture is the DECAL and the destination texture is where the decal is applied. The optional rgb flags are used for masking the decal. In the example below the decals background is masked out using 255,0,255 The two test images I used:   ; Applying a DECAL to a texture
; Syntax Error
Graphics3D 640,480
SetBuffer BackBuffer()
cam=CreateCamera() : light=CreateLight()
cube=CreateCube() : MoveEntity cube,0,0,4
cubetex=LoadTexture("wood.jpg")
EntityTexture cube,cubetex
decal=LoadTexture("decal.png")
Repeat
TurnEntity cube,0.5,0.6,0.7
If KeyHit(57) ApplyDecal decal,cubetex ,255,0,255
RenderWorld
Text 10,10,"Press [SPACE] to apply the decal ..."
Flip
Until KeyHit(1)
End
; Apply source texture to destination texture (with optional masking)
Function ApplyDecal(sourceb,destb,maskR=0,maskG=0,maskB=0)
Local gb=GraphicsBuffer() , rgb
Local sb=TextureBuffer(sourceb) , db=TextureBuffer(destb)
Local maxw=TextureWidth(sourceb) , maxh=TextureHeight(sourceb)
If TextureWidth(destb)<maxw Then maxw=TextureWidth(destb)
If TextureHeight(destb)<maxh Then maxh=TextureHeight(destb)
LockBuffer sb : LockBuffer db
For x=0 To maxw-1
For y=0 To maxh-1
rgb=ReadPixelFast(x,y,sb) And $00FFFFFF
If Not rgb=((maskR Shl 16)+(maskG Shl 8)+maskB)
WritePixelFast x,y,(rgb Or $FF000000),db
EndIf
Next
Next
UnlockBuffer sb : UnlockBuffer db
SetBuffer gb
End Function
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| hi, Thanks very much! Im planning on making a 1024x1024 texture as a groundmap, and to paint the texture onto the ground directly, and allow things like rocks to change the colour of the texture, so this should work well. thanks again! :-) :-) |
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| The same thing can be accomplished with multitexturing and normal transparency ie. masked or alpha textures. Depending on how many levels of multitexturing you have there wouldn't be any slowdown (even really old video hardware supports two texture layers per pass; newer hardware supports several times that) and it is much faster to setup/load than using WritePixel commands. |
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| Hi there, Yeah I originally thought of using multitexturing, but I want the texture to be of random islands and reefs with actual textured beaches smoothly flowing into the water, kind of like photorealistic terrain...a pretty hard task (random photorealistic terrain) but hopefully this *might* work. I have already come up against one problem though, when I use; WritePixelFast x+200,y+200,(rgb Or $FF000000),db The x & y of the decal is displaced by 200, but when I use a variable; xno=200 yno=200 WritePixelFast x+xno,y+yno,(rgb Or $FF000000),db It doesnt work at all :-( Any ideas? Thanks :-) |
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| Pass xno and yno into the function as parameters or make them global. |
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| Hi, It works! Thankyou! :-) |
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