raylib-src/examples/core/core_quat_conversion.c

/*******************************************************************************************
*
*   raylib [core] example - quat conversions
*
*   Generally you should really stick to eulers OR quats...
*   This tests that various conversions are equivalent.
*
*   This example has been created using raylib 3.5 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Example contributed by Chris Camacho (@chriscamacho) and reviewed by Ramon Santamaria (@raysan5)
*
*   Copyright (c) 2020 Chris Camacho (@chriscamacho) and Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

#include "raymath.h"

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

    InitWindow(screenWidth, screenHeight, "raylib [core] example - quat conversions");
    
    Camera3D camera = { 0 };
    camera.position = (Vector3){ 0.0f, 10.0f, 10.0f };  // Camera position
    camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };      // Camera looking at point
    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };          // Camera up vector (rotation towards target)
    camera.fovy = 45.0f;                                // Camera field-of-view Y
    camera.projection = CAMERA_PERSPECTIVE;                   // Camera mode type

    Mesh mesh = GenMeshCylinder(0.2f, 1.0f, 32); 
    Model model = LoadModelFromMesh(mesh);
    
    // Some required variables
    Quaternion q1 = { 0 };
    Matrix m1 = { 0 }, m2 = { 0 }, m3 = { 0 }, m4 = { 0 };
    Vector3 v1 = { 0 }, v2 = { 0 };

    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------
   
    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        //--------------------------------------------------------------------------------------
        if (!IsKeyDown(KEY_SPACE))
        {
            v1.x += 0.01f;
            v1.y += 0.03f;
            v1.z += 0.05f;
        }

        if (v1.x > PI*2) v1.x -= PI*2;
        if (v1.y > PI*2) v1.y -= PI*2;
        if (v1.z > PI*2) v1.z -= PI*2;
        
        q1 = QuaternionFromEuler(v1.x, v1.y, v1.z);
        m1 = MatrixRotateZYX(v1);
        m2 = QuaternionToMatrix(q1);

        q1 = QuaternionFromMatrix(m1);
        m3 = QuaternionToMatrix(q1);
        
        v2 = QuaternionToEuler(q1);       
        v2.x *= DEG2RAD; 
        v2.y *= DEG2RAD; 
        v2.z *= DEG2RAD; 
        
        m4 = MatrixRotateZYX(v2);
        //--------------------------------------------------------------------------------------
        
        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();

            ClearBackground(RAYWHITE);
            
            BeginMode3D(camera);

                model.transform = m1;
                DrawModel(model, (Vector3){ -1, 0, 0 }, 1.0f, RED);
                model.transform = m2;
                DrawModel(model, (Vector3){ 1, 0, 0 }, 1.0f, RED);
                model.transform = m3;
                DrawModel(model, (Vector3){ 0, 0, 0 }, 1.0f, RED);
                model.transform = m4;
                DrawModel(model, (Vector3){ 0, 0, -1 }, 1.0f, RED);

                DrawGrid(10, 1.0f);
 
            EndMode3D();
        
            if (v2.x < 0) v2.x += PI*2;
            if (v2.y < 0) v2.y += PI*2;
            if (v2.z < 0) v2.z += PI*2;
            
            Color cx,cy,cz;
            cx = cy = cz = BLACK;
            if (v1.x == v2.x) cx = GREEN;
            if (v1.y == v2.y) cy = GREEN;
            if (v1.z == v2.z) cz = GREEN;
            
            DrawText(TextFormat("%2.3f", v1.x), 20, 20, 20, cx);
            DrawText(TextFormat("%2.3f", v1.y), 20, 40, 20, cy);
            DrawText(TextFormat("%2.3f", v1.z), 20, 60, 20, cz);

            DrawText(TextFormat("%2.3f", v2.x), 200, 20, 20, cx);
            DrawText(TextFormat("%2.3f", v2.y), 200, 40, 20, cy);
            DrawText(TextFormat("%2.3f", v2.z), 200, 60, 20, cz);

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

    // De-Initialization
    //--------------------------------------------------------------------------------------
    UnloadModel(model);   // Unload model data (mesh and materials)
    
    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}