check SDL anti aliasing line

Author: kwanCCC

include/util.h

@@ -0,0 +1,23 @@
+#ifndef _UTIL_H_
+#define _UTIL_H_
+
+class Util;
+
+static inline void swap(int* a, int* b);
+
+// returns absolute value of number
+static inline float absolute(float x);
+
+// returns integer part of a floating point number
+static inline int iPartOfNumber(float x);
+
+// rounds off a number
+static inline int roundNumber(float x);
+
+// returns fractional part of a number
+static inline float fPartOfNumber(float x);
+
+// returns 1 - fractional part of number
+static inline float rfPartOfNumber(float x);
+
+#endif  //_UTIL_H_

src/main.cpp

@@ -70,8 +70,12 @@ float rfPartOfNumber(float x) { return 1 - fPartOfNumber(x); }
 // 0<=brightness<=1. We can use your own library
 // to draw on screen
 void drawPixel(int x, int y, float brightness) {
+  // 255,192,203
   int c = 255 * brightness;
-  SDL_SetRenderDrawColor(pRenderer, c, c, c, 255);
+  int r = 255 * brightness;
+  int g = 192 * brightness;
+  int b = 203 * brightness;
+  SDL_SetRenderDrawColor(pRenderer, r, g, b, 255);
   SDL_RenderDrawPoint(pRenderer, x, y);
 }
 
@@ -144,7 +148,7 @@ int sdl() {
     SDL_RenderClear(pRenderer);
 
     // draws a black AALine
-    drawAALine(80, 200, 550, 150);
+    drawAALine(80, 10, 550, 150);
 
     // show the window
     SDL_RenderPresent(pRenderer);

src/util.cpp

@@ -0,0 +1,32 @@
+#include "util.h"
+
+static inline void swap(int* a, int* b) {
+  int temp = *a;
+  *a = *b;
+  *b = temp;
+}
+
+// returns absolute value of number
+static inline float absolute(float x) {
+  if (x < 0)
+    return -x;
+  else
+    return x;
+}
+
+// returns integer part of a floating point number
+static inline int iPartOfNumber(float x) { return (int)x; }
+
+// rounds off a number
+static inline int roundNumber(float x) { return iPartOfNumber(x + 0.5); }
+
+// returns fractional part of a number
+static inline float fPartOfNumber(float x) {
+  if (x > 0)
+    return x - iPartOfNumber(x);
+  else
+    return x - (iPartOfNumber(x) + 1);
+}
+
+// returns 1 - fractional part of number
+static inline float rfPartOfNumber(float x) { return 1 - fPartOfNumber(x); }