Bitmap/Bresenham's line algorithm: Difference between revisions
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}</lang>
=={{header|Phix}}==
Modified copy of [[Bitmap/Bresenham%27s_line_algorithm#Euphoria|Euphoria]], with a bigger bitmap and a simpler pattern.
Requires new_image() from [[Bitmap#Phix|Bitmap]], write_ppm() from [[Bitmap/Write_a_PPM_file#Phix|Write_a_PPM_file]].
Included as demo\rosetta\Bresenham_line.exw, results may be verified with demo\rosetta\viewppm.exw
<lang Phix>function bresLine(sequence screenData, integer x0, integer y0, integer x1, integer y1, integer colour)
-- The line algorithm
integer deltaX = abs(x1-x0),
deltaY = abs(y1-y0),
stepX = iff(x0<x1,1,-1),
stepY = iff(y0<y1,1,-1),
lineError = iff(deltaX>deltaY,deltaX,-deltaY),
prevle
lineError = round(lineError/2,1)
while 1 do
if x0>=1 and x0<=length(screenData)
and y0>=1 and y0<=length(screenData[x0]) then
screenData[x0][y0] = colour
end if
if x0=x1 and y0=y1 then exit end if
prevle = lineError
if prevle>-deltaX then
lineError -= deltaY
x0 += stepX
end if
if prevle<deltaY then
lineError += deltaX
y0 += stepY
end if
end while
return screenData
end function
sequence screenData = new_image(400,300,black)
screenData = bresLine(screenData,100,1,50,300,red)
screenData = bresLine(screenData,1,180,400,240,green)
screenData = bresLine(screenData,200,1,400,150,white)
screenData = bresLine(screenData,195,1,205,300,blue)
write_ppm("bresenham.ppm",screenData)</lang>
=={{header|PicoLisp}}==
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