Implement shaders (#1)

Reviewed-on: #1

	* Start implementing shaders and move vector code to dedicated files
	* Extract shader into its own header
	* Ensure pixel coordinates are within bounds
	* Refactor shader code and implement fragment shaders
	* Create shaders
	* Reorganise code
Co-authored-by: Abdelrahman <said.abdelrahman89@gmail.com>
Co-committed-by: Abdelrahman <said.abdelrahman89@gmail.com>

src/utils/utils.c

@@ -0,0 +1,10 @@
+#include "utils.h"
+#include "aliases.h"
+
+i64 absolute(i64 value) {
+  if (value >= 0) {
+    return value;
+  }
+
+  return value * -1;
+}

src/utils/utils.h

@@ -0,0 +1,18 @@
+#ifndef UTILS_H
+#define UTILS_H
+
+#include "aliases.h"
+#define swap(T, v0, v1)                                                        \
+  do {                                                                         \
+    T tmp = v0;                                                                \
+    v0 = v1;                                                                   \
+    v1 = tmp;                                                                  \
+  } while (0)
+
+#define min(a, b) (a <= b ? a : b)
+#define max(a, b) (a >= b ? a : b)
+#define clamp(val, minimum, maximum) (min(maximum, max(minimum, val)))
+
+i64 absolute(i64 value);
+
+#endif // UTILS_H