More measures against 5th and the improved version in issue ssloy#28

Somehow my version seems to still win :D gotta test the wireframe test

Author: OAguinagalde

main.cpp

@@ -33,10 +33,8 @@ const TGAColor red = TGAColor(255, 0, 0, 255);
 const TGAColor green = TGAColor(0, 255, 0, 255);
 const TGAColor blue = TGAColor(0, 0, 255, 255);
 
-#define line line1
-
 // Copyed from the lesson to test performance, I win!!!
-void line2(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) { 
+void line4th(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) { 
     auto start = std::chrono::high_resolution_clock::now();
     bool steep = false; 
     if (std::abs(x0-x1)<std::abs(y0-y1)) { 
@@ -66,6 +64,80 @@ void line2(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) {
         } 
     } 
     measure_since(start);
+}
+
+void line5th(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) { 
+    auto start = std::chrono::high_resolution_clock::now();
+
+    bool steep = false; 
+    if (std::abs(x0-x1)<std::abs(y0-y1)) { 
+        std::swap(x0, y0); 
+        std::swap(x1, y1); 
+        steep = true; 
+    } 
+    if (x0>x1) { 
+        std::swap(x0, x1); 
+        std::swap(y0, y1); 
+    } 
+    int dx = x1-x0; 
+    int dy = y1-y0; 
+    int derror2 = std::abs(dy)*2; 
+    int error2 = 0; 
+    int y = y0; 
+    for (int x=x0; x<=x1; x++) { 
+        if (steep) { 
+            image.set(y, x, color); 
+        } else { 
+            image.set(x, y, color); 
+        } 
+        error2 += derror2; 
+        if (error2 > dx) { 
+            y += (y1>y0?1:-1); 
+            error2 -= dx*2; 
+        } 
+    }
+    measure_since(start);
+} 
+
+void line5thImprovedIssue28(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) { 
+    auto start = std::chrono::high_resolution_clock::now();
+
+    bool steep = false; 
+    if (std::abs(x0-x1)<std::abs(y0-y1)) { 
+        std::swap(x0, y0); 
+        std::swap(x1, y1); 
+        steep = true; 
+    } 
+    if (x0>x1) { 
+        std::swap(x0, x1); 
+        std::swap(y0, y1); 
+    } 
+    int dx = x1-x0; 
+    int dy = y1-y0; 
+    int derror2 = std::abs(dy)*2; 
+    int error2 = 0; 
+    int y = y0;
+    const int yincr = (y1>y0? 1 : -1);
+    if(steep) {
+        for(int x = x0; x<=x1; ++x) {
+            image.set(y, x, color);
+            error2 += derror2;
+            if(error2 > dx) {
+                y += (y1>y0? 1 : -1);
+                error2 -= dx*2;
+            }
+        }
+    } else {
+        for(int x = x0; x<=x1; ++x) {
+            image.set(x, y, color);
+            error2 += derror2;
+            if(error2 > dx) {
+                y += yincr;
+                error2 -= dx*2;
+            }
+        }
+    }
+    measure_since(start);
 } 
 
 void line1(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) {
@@ -117,9 +189,23 @@ void line1(int x0, int y0, int x1, int y1, TGAImage &image, TGAColor color) {
 
 int main(int argc, char** argv) {
     TGAImage image(100, 100, TGAImage::RGB);
-    line(13, 20, 80, 40, image, white); 
-    line(20, 13, 40, 80, image, red); 
-    line(80, 40, 13, 20, image, red);
+
+    line4th(13, 20, 80, 40, image, white); 
+    line4th(20, 13, 40, 80, image, red); 
+    line4th(80, 40, 13, 20, image, red);
+
+    line5th(13, 20, 80, 40, image, white); 
+    line5th(20, 13, 40, 80, image, red); 
+    line5th(80, 40, 13, 20, image, red);
+
+    line5thImprovedIssue28(13, 20, 80, 40, image, white); 
+    line5thImprovedIssue28(20, 13, 40, 80, image, red); 
+    line5thImprovedIssue28(80, 40, 13, 20, image, red);
+    
+    line1(13, 20, 80, 40, image, white); 
+    line1(20, 13, 40, 80, image, red); 
+    line1(80, 40, 13, 20, image, red);
+    
     image.flip_vertically(); // i want to have the origin at the left bottom corner of the image
     image.write_tga_file("output.tga");
     return 0;