/*******************************************************************************************
*
*   raylib [core] example - Basic window
*
*   Example originally created with raylib 4.5, last time updated with raylib 4.5
*
*   Example contributed by <user_name> (@<user_github>) and reviewed by Ramon Santamaria (@raysan5)
*
*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
*   BSD-like license that allows static linking with closed source software
*
*   Copyright (c) 2023 <user_name> (@<user_github>)
*
********************************************************************************************/

#include "raylib.h"
#include "raymath.h"
#include "rlgl.h"

#include <printf.h>

#define RLIGHTS_IMPLEMENTATION
#include "rlights.h"

#if defined(PLATFORM_DESKTOP)
    #define GLSL_VERSION            330
#else   // PLATFORM_ANDROID, PLATFORM_WEB
    #define GLSL_VERSION            100
#endif

//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 800;
    const int screenHeight = 450;

    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - vertex displacement");

    Camera camera = {0};
    camera.position = (Vector3) {20.0f, 5.0f, -20.0f};
    camera.target = (Vector3) {0.0f, 0.0f, 0.0f};
    camera.up = (Vector3) {0.0f, 1.0f, 0.0f};
    camera.fovy = 60.0f;
    camera.projection = CAMERA_PERSPECTIVE;

    Mesh planeMesh = GenMeshPlane(50, 50, 50, 50);
    Model planeModel = LoadModelFromMesh(planeMesh);

    Shader shader = LoadShader(
        TextFormat("resources/shaders/glsl%i/vertex_displacement.vs", GLSL_VERSION),
        TextFormat("resources/shaders/glsl%i/vertex_displacement.fs", GLSL_VERSION)
        );
    shader.locs[SHADER_LOC_VECTOR_VIEW] = GetShaderLocation(shader, "viewPos");

    int ambientLoc = GetShaderLocation(shader, "ambient");
    SetShaderValue(shader, ambientLoc, (float[4]){ 0.1f, 0.1f, 0.1f, 1.0f }, SHADER_UNIFORM_VEC4);
    
    Image perlinNoiseImage = GenImagePerlinNoise(512, 512, 0, 0, 1.0f);
    Texture perlinNoiseMap = LoadTextureFromImage(perlinNoiseImage);
    UnloadImage(perlinNoiseImage);

    int perlinNoiseMapLoc = GetShaderLocation(shader, "perlinNoiseMap");
    rlEnableShader(shader.id);
    rlActiveTextureSlot(1);
    rlEnableTexture(perlinNoiseMap.id);
    rlSetUniformSampler(perlinNoiseMapLoc, 1);
    

    planeModel.materials[0].shader = shader;

    float time = 0.0f;

    SetTargetFPS(60);
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        UpdateCamera(&camera, CAMERA_FREE);

        float cameraPos[3] = { camera.position.x, camera.position.y, camera.position.z };
        SetShaderValue(shader, shader.locs[SHADER_LOC_VECTOR_VIEW], cameraPos, SHADER_UNIFORM_VEC3);

        time += GetFrameTime();
        SetShaderValue(shader, GetShaderLocation(shader, "time"), &time, SHADER_UNIFORM_FLOAT); 

        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();

            ClearBackground(RAYWHITE);

            BeginMode3D(camera);

                BeginShaderMode(shader);
                    DrawModel(planeModel, (Vector3){ 0.0f, 0.0f, 0.0f }, 1.0f, (Color) {255, 255, 255, 255});
                EndShaderMode();

            EndMode3D();

            DrawText("Displacement mapping", 10, 10, 20, DARKGRAY);
            DrawFPS(10, 40);

        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------

    UnloadShader(shader);
    UnloadModel(planeModel);

    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}