June 2018 Update

Task/Bitmap-Bresenhams-line-algorithm/Julia/bitmap-bresenhams-line-algorithm.julia

@@ -1,23 +1,27 @@
-function line(img, x0::Int, y0::Int, x1::Int, y1::Int, col)
-	dx = int(abs(x1-x0))
-	dy = int(abs(y1-y0))
+function drawline!(img::Matrix{T}, x0::Int, y0::Int, x1::Int, y1::Int, col::T) where T
+    δx = abs(x1 - x0)
+    δy = abs(y1 - y0)
+    δe = abs(δy / δx)
+    er = 0.0
 
-	sx = x0<x1 ? 1 : -1
-	sy = y0<y1 ? 1 : -1;
+    y = y0
+    for x in x0:x1
+        img[x, y] = col
+        er += δe
+        if er > 0.5
+            y  += 1
+            er -= 1.0
+        end
+    end
 
-	err = (dx>dy ? dx : -dy)/2
-
-	while true
-		@inbounds img[x0,y0]=col
-		if (x0==x1 && y0==y1); break; end
-		e2 = err;
-		if e2 > -dx
-			err -= dy
-			x0 += sx
-		end
-		if e2 < dy
-			err += dx
-			y0 += sy
-		end
-	end
+    return img
 end
+
+using Images
+
+img = fill(Gray(255.0), 5, 5);
+println("\nImage:")
+display(img); println()
+drawline!(img, 1, 1, 5, 5, Gray(0.0));
+println("\nModified image:")
+display(img); println()