feat: add texture coordinates

Engine/engine/constants.hpp

@@ -137,8 +137,6 @@ namespace constants
         "./Shaders/fragmentShaderSource.fs"
     };
 
-
-
     inline const char *FRAGMENT_SHADER_SOURCE_YELLOW {
         "#version 330 core\n"
         "out vec4 FragColor;\n"
@@ -203,7 +201,6 @@ namespace constants
 
     inline constexpr size_t TRIANGLE_COLORS_SIZE = { sizeof(TRIANGLE_COLORS) };
 
-
     // compare with square done with only vertices:
     /*
     float vertices[] = {
@@ -236,6 +233,13 @@ namespace constants
 
     inline constexpr int MAX_DRAW_CALL = { 10 };
 
+    // https://learnopengl.com/img/getting-started/tex_coords.png
+    inline constexpr float TEXTURE_COORDINATES[] {
+        0.0f, 0.0f,  // lower-left corner  
+        1.0f, 0.0f,  // lower-right corner
+        0.5f, 1.0f   // top-center corner
+    };
+
 }
 
 #endif