dxSetPixelColor circel

[ZuluTangoDelta]

Hi i try to draw a circel with dxSetPixelColor for a texture so i can use it for a terrain shader.A recental works fine but when i try to change the colors of pixels in a circel radius >5 it lags ver much i select the pixels with math.cos and math. sin.

[xXMADEXx]

https://wiki.multitheftauto.com/wiki/DxDrawCircle

https://wiki.multitheftauto.com/wiki/Dx ... tialCircle

[ZuluTangoDelta]

So you mean i should use rendertarget and draw a circel on it and give it to the shader?im not a pro in shaders so i dont know which solution is the best.But i need to draw a filled circel.I solve it without sin and cos and use pythagoras.

  
function draw (radius,x,y,r,g,b) --x,y the position of the player so the sandtex is drawn under the player 
local ox,oy,oz = getElementPosition(obj1) --obj1 is the testterrain on which the shader draws the sandtexture 
nx = (ox+x)*5+250-radius/2 
ny = (oy-y)*5+250-radius/2 
local pixels = dxGetTexturePixels (mapdraw) --mapdraw is the empty texture on which i draw the different colors so the shader can replace the colors for different textures  
  
for i=0,radius*2,1 do 
local x = -radius+i 
local y = math.sqrt(((radius*radius)-(x*x))) 
for ly=0,y*2,1 do 
dxSetPixelColor (pixels,nx+x, ny+y-ly, r,g,b, 255) 
end 
end 
  
dxSetTexturePixels (mapdraw, pixels) 
end 
  

this texture is given to the sahder which replace the white circel with a new sandtexture on a terrain.I hope you understood me

[DiSaMe]

Instead of drawing it pixel by pixel you could draw it row by row out of horizontal lines (1 pixel height rectangles) using dxDrawRectangle.

[ZuluTangoDelta]

Ok thanks the only problem is to change the alpha of the outer pixels of the circel so i can use lerp(sand,gras,saturate(1-blendcolor.a)); in the shader so the sandtexture has smoother edges.Have you a solution for that?

[arezu]

You can change to use a render target that you make transparent, and then when you want to draw a circle, draw an image with a circle in it with smoothed edges/glow (make the edges go from no transparency to full transparency in photoshop or whatever) on the render target. You can then blend using lerp in shader.

Drawing to render target using an image is much faster than using pixel functions.