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

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;