diff --git a/tinyrender/main.cpp b/tinyrender/main.cpp
index 55d0e70..e1aceb4 100644
--- a/tinyrender/main.cpp
+++ b/tinyrender/main.cpp
@@ -26,13 +26,14 @@ void line(int x0, int y0, int x1, int y1, TGAImage& image, TGAColor color) {
 	{
 		if (steep) 
 		{
-			image.set(x, y, color);
+			image.set(y, x, color);
 		}
 		else
 		{
 			image.set(x, y, color);
 		}
 		error2 += derror2;
+
 		if (error2 > dx) // 误差值，提供从当前位置到最佳直线的距离
 		{
 			y += (y1 > y0 ? 1 : -1);
@@ -44,7 +45,13 @@ void line(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(52, 41,90,70,image ,red);
+	for (int i = 0; i < 1000000; i++)
+	{
+		line(13, 20, 80, 40, image, white);
+		line(20, 13, 40, 80, image, red);
+		line(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;