really basic painting into an array (as bitmap)

drawfilled1.jl

# from
# http://stackoverflow.com/questions/1201200/fast-algorithm-for-drawing-filled-circles#1201304
#
# void DrawFilledCircle(int x0, int y0, int radius)
# {
#     int x = radius;
#     int y = 0;
#     int xChange = 1 - (radius << 1);
#     int yChange = 0;
#     int radiusError = 0;

#     while (x >= y)
#     {
#         for (int i = x0 - x; i <= x0 + x; i++)
#         {
#             SetPixel(i, y0 + y);
#             SetPixel(i, y0 - y);
#         }
#         for (int i = x0 - y; i <= x0 + y; i++)
#         {
#             SetPixel(i, y0 + x);
#             SetPixel(i, y0 - x);
#         }

#         y++;
#         radiusError += yChange;
#         yChange += 2;
#         if (((radiusError << 1) + xChange) > 0)
#         {
#             x--;
#             radiusError += xChange;
#             xChange += 2;
#         }
#     }
# }

function drawFilledCircle!(m::Array{Uint32,2},x0::Int,y0::Int,radius::Int,c::Int)

	x::Int = radius
	y::Int = 0
	xChange::Int = 1 - (radius << 1)
	yChange::Int = 0;
	radiusError::Int = 0

	while x >= y
		for i = (x0-x):(x0+x)
			m[y0+y,i] = c
			m[y0-y,i] = c
		end
		for i = (x0-y):(x0+y)
			m[y0+x,i] = c
			m[y0-x,i] = c
		end

		y +=1 
		radiusError += yChange;
		yChange += 2
		if ((radiusError << 1) + xChange) > 0
			x -= 1
			radiusError += xChange
			xChange += 2
		end
	end
end

function random_dots(n::Int,yrange::Int,xrange::Int,radius::Int)
	x = int(rand(n)*xrange)
	y = int(rand(n)*yrange)
	# clamping the coordinates, so no boundary processing in painting
	for i = 1:length(x)
		x[i] = clamp(x[i],radius+2,xrange-radius-2);
		y[i] = clamp(y[i],radius+2,yrange-radius-2);
	end
	c = int(rand(length(x))*100) # random color
	x,y,c
end

function Lpaint(x::Array{Int,1},y::Array{Int,1},c::Array{Int,1},m::Array{Uint32,2},radius::Int)
	for i = 1:length(x)
		drawFilledCircle!(m,x[i],y[i],radius,c[i])
	end
end

m = zeros(Uint32,800,1000); # out bitmap, y,x 
n_dots = [30,100,300,1000,3000,10000,30000,100000,300000,1000000,3000000,10000000]
x,y,c =  random_dots(maximum(n_dots),800,1000,5)

for n in n_dots
	display(n)
    @time Lpaint(x[1:n],y[1:n],c[1:n],m,5)
end