cache optimized rectangle drawing and made sure the methods could be inlined

shaders/shader.cpp

@@ -10,12 +10,50 @@ namespace UwU {
   // shader prototype
   class Shader {
     public:
-      Shader() {}
+      //COLOR Shader
+      Shader(Color color) {
+        this->shaderType = COLOR;
+        this->c0 = color;
+      }
 
-      Color color(uint16_t u, uint16_t v) {
-        (void)u;
-        (void)v;
-        return Color();
+      //HGRADIENT or VGRADIENT shader
+      Shader(Direction direction, uint16_t uv0, uint16_t uv1, Color c0, Color c1) {
+        this->c0 = c0;
+        this->c1 = c1;
+        switch (direction) {
+          case H:
+            shaderType = HGRADIENT;
+            this->u0 = uv0;
+            this->scale = 0xffffffff / (1 + (uint32_t)uv1 - (uint32_t)uv0);
+            break;
+          case V:
+            shaderType = VGRADIENT;
+            this->v0 = uv0;
+            this->scale = 0xffffffff / (1 + (uint32_t)uv1 - (uint32_t)uv0);
+            break;
+        }
+      }
+
+      // BUFFER shader
+      // Shader(uint16_t u, uint16_t v, Buffer buffer) {
+      //   this->shaderType = BUFFER;
+      //   this->u0 = u;
+      //   this->v0 = v;
+      // }
+
+      ShaderType shaderType;
+      uint16_t u0;
+      uint16_t v0;
+      Color c0;
+      Color c1;
+      uint32_t scale;
+  };
+
+  class ShaderMethods {
+    public:
+      static Color gradient(uint16_t uv0, uint32_t scale, Color c0, Color c1, uint16_t uv) {
+        uint32_t t = (((uint32_t)uv - (uint32_t)uv0) * scale) / 0x01000000;
+        return Helpers::lerpColor(c0, c1, (uint8_t)t);
       }
   };
 }