text: /*******************************************************************************************
  *
  *   raylib [models] example - Plane rotations (yaw, pitch, roll)
  *
  *   This example has been created using raylib 1.8 (www.raylib.com)
  *   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
  *
  *   Example contributed by Berni (@Berni8k) and reviewed by Ramon Santamaria (@raysan5)
  *
  *   Copyright (c) 2017 Berni (@Berni8k) and Ramon Santamaria (@raysan5)
  *
  ********************************************************************************************/
  
  #include "raylib.h"
  #include "raymath.h"
  
  // Draw angle gauge controls
  void DrawAngleGauge(Texture2D angleGauge, int x, int y, float angle, char title[], Color color);
  
  int main(void)
  {
      // Initialization
      //--------------------------------------------------------------------------------------
      const int screenWidth = 800;
      const int screenHeight = 450;
  
      InitWindow(screenWidth, screenHeight, "raylib [models] example - plane rotations (yaw, pitch, roll)");
  
      Texture2D texAngleGauge = LoadTexture("resources/angle_gauge.png");
      Texture2D texBackground = LoadTexture("resources/background.png");
      Texture2D texPitch = LoadTexture("resources/pitch.png");
      Texture2D texPlane = LoadTexture("resources/plane.png");
  
      RenderTexture2D framebuffer = LoadRenderTexture(192, 192);
  
      // Model loading
      Model model = LoadModel("resources/plane.obj");     // Load OBJ model
      model.materials[0].maps[MATERIAL_MAP_DIFFUSE].texture = LoadTexture("resources/plane_diffuse.png"); // Set map diffuse texture
  
      GenTextureMipmaps(&model.materials[0].maps[MATERIAL_MAP_DIFFUSE].texture);
  
      Camera camera = { 0 };
      camera.position = (Vector3){ 0.0f, 60.0f, -120.0f };// Camera position perspective
      camera.target = (Vector3){ 0.0f, 12.0f, 0.0f };     // Camera looking at point
      camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };          // Camera up vector (rotation towards target)
      camera.fovy = 30.0f;                                // Camera field-of-view Y
      camera.type = CAMERA_PERSPECTIVE;                   // Camera type
  
      float pitch = 0.0f;
      float roll = 0.0f;
      float yaw = 0.0f;
  
      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
          //----------------------------------------------------------------------------------
  
          // Plane roll (x-axis) controls
          if (IsKeyDown(KEY_LEFT)) roll += 1.0f;
          else if (IsKeyDown(KEY_RIGHT)) roll -= 1.0f;
          else
          {
              if (roll > 0.0f) roll -= 0.5f;
              else if (roll < 0.0f) roll += 0.5f;
          }
  
          // Plane yaw (y-axis) controls
          if (IsKeyDown(KEY_S)) yaw += 1.0f;
          else if (IsKeyDown(KEY_A)) yaw -= 1.0f;
          else
          {
              if (yaw > 0.0f) yaw -= 0.5f;
              else if (yaw < 0.0f) yaw += 0.5f;
          }
  
          // Plane pitch (z-axis) controls
          if (IsKeyDown(KEY_DOWN)) pitch += 0.6f;
          else if (IsKeyDown(KEY_UP)) pitch -= 0.6f;
          else
          {
              if (pitch > 0.3f) pitch -= 0.3f;
              else if (pitch < -0.3f) pitch += 0.3f;
          }
  
          // Wraps the phase of an angle to fit between -180 and +180 degrees
          int pitchOffset = pitch;
          while (pitchOffset > 180) pitchOffset -= 360;
          while (pitchOffset < -180) pitchOffset += 360;
          pitchOffset *= 10;
  
          /* matrix transform done with multiplication to combine rotations
          Matrix transform = MatrixIdentity();
  
          transform = MatrixMultiply(transform, MatrixRotateZ(DEG2RAD*roll));
          transform = MatrixMultiply(transform, MatrixRotateX(DEG2RAD*pitch));
          transform = MatrixMultiply(transform, MatrixRotateY(DEG2RAD*yaw));
  
          model.transform = transform;
          */
          // matrix created from multiple axes at once
          model.transform = MatrixRotateXYZ((Vector3){DEG2RAD*pitch,DEG2RAD*yaw,DEG2RAD*roll});
  
          //----------------------------------------------------------------------------------
          // Draw
          //----------------------------------------------------------------------------------
          BeginDrawing();
  
              ClearBackground(RAYWHITE);
  
              // Draw framebuffer texture (Ahrs Display)
              int centerX = framebuffer.texture.width/2;
              int centerY = framebuffer.texture.height/2;
  
              BeginTextureMode(framebuffer);
              
                  ClearBackground(RAYWHITE);
                  BeginBlendMode(BLEND_ALPHA);
  
                  DrawTexturePro(texBackground, (Rectangle){ 0, 0, texBackground.width, texBackground.height },
                                 (Rectangle){ centerX, centerY, texBackground.width, texBackground.height},
                                 (Vector2){ texBackground.width/2, texBackground.height/2 + pitchOffset }, roll, WHITE);
  
                  DrawTexturePro(texPitch, (Rectangle){ 0, 0, texPitch.width, texPitch.height },
                                 (Rectangle){ centerX, centerY, texPitch.width, texPitch.height },
                                 (Vector2){ texPitch.width/2, texPitch.height/2 + pitchOffset }, roll, WHITE);
  
                  DrawTexturePro(texPlane, (Rectangle){ 0, 0, texPlane.width, texPlane.height },
                                 (Rectangle){ centerX, centerY, texPlane.width, texPlane.height },
                                 (Vector2){ texPlane.width/2, texPlane.height/2 }, 0, WHITE);
  
                  EndBlendMode();
  
              EndTextureMode();
  
              // Draw 3D model (recomended to draw 3D always before 2D)
              BeginMode3D(camera);
  
                  DrawModel(model, (Vector3){ 0, 6.0f, 0 }, 1.0f, WHITE);   // Draw 3d model with texture
                  DrawGrid(10, 10.0f);
  
              EndMode3D();
  
              // Draw 2D GUI stuff
              DrawAngleGauge(texAngleGauge, 80, 70, roll, "roll", RED);
              DrawAngleGauge(texAngleGauge, 190, 70, pitch, "pitch", GREEN);
              DrawAngleGauge(texAngleGauge, 300, 70, yaw, "yaw", SKYBLUE);
  
              DrawRectangle(30, 360, 260, 70, Fade(SKYBLUE, 0.5f));
              DrawRectangleLines(30, 360, 260, 70, Fade(DARKBLUE, 0.5f));
              DrawText("Pitch controlled with: KEY_UP / KEY_DOWN", 40, 370, 10, DARKGRAY);
              DrawText("Roll controlled with: KEY_LEFT / KEY_RIGHT", 40, 390, 10, DARKGRAY);
              DrawText("Yaw controlled with: KEY_A / KEY_S", 40, 410, 10, DARKGRAY);
  
              // Draw framebuffer texture
              DrawTextureRec(framebuffer.texture, (Rectangle){ 0, 0, framebuffer.texture.width, -framebuffer.texture.height },
                             (Vector2){ screenWidth - framebuffer.texture.width - 20, 20 }, Fade(WHITE, 0.8f));
  
              DrawRectangleLines(screenWidth - framebuffer.texture.width - 20, 20, framebuffer.texture.width, framebuffer.texture.height, DARKGRAY);
  
          EndDrawing();
          //----------------------------------------------------------------------------------
      }
  
      // De-Initialization
      //--------------------------------------------------------------------------------------
  
      // Unload all loaded data
      UnloadTexture(model.materials[0].maps[MATERIAL_MAP_DIFFUSE].texture);
      UnloadModel(model);
  
      UnloadRenderTexture(framebuffer);
  
      UnloadTexture(texAngleGauge);
      UnloadTexture(texBackground);
      UnloadTexture(texPitch);
      UnloadTexture(texPlane);
  
      CloseWindow();        // Close window and OpenGL context
      //--------------------------------------------------------------------------------------
  
      return 0;
  }
  
  // Draw angle gauge controls
  void DrawAngleGauge(Texture2D angleGauge, int x, int y, float angle, char title[], Color color)
  {
      Rectangle srcRec = { 0, 0, angleGauge.width, angleGauge.height };
      Rectangle dstRec = { x, y, angleGauge.width, angleGauge.height };
      Vector2 origin = { angleGauge.width/2, angleGauge.height/2};
      int textSize = 20;
  
      DrawTexturePro(angleGauge, srcRec, dstRec, origin, angle, color);
  
      DrawText(TextFormat("%5.1f", angle), x - MeasureText(TextFormat("%5.1f", angle), textSize) / 2, y + 10, textSize, DARKGRAY);
      DrawText(title, x - MeasureText(title, textSize) / 2, y + 60, textSize, DARKGRAY);
  }
  