example review: models_first_person_maze

Added walls collision check

examples/models/models_first_person_maze.c

@@ -23,16 +23,19 @@ int main()
     // Define the camera to look into our 3d world
     Camera camera = {{ 0.2f, 0.4f, 0.2f }, { 0.0f, 0.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }, 45.0f, 0 };
 
-    Image image = LoadImage("resources/cubicmap.png");      // Load cubicmap image (RAM)
-    Texture2D cubicmap = LoadTextureFromImage(image);       // Convert image to texture to display (VRAM)
-    Mesh mesh = GenMeshCubicmap(image, (Vector3){ 1.0f, 1.0f, 1.0f });
+    Image imMap = LoadImage("resources/cubicmap.png");      // Load cubicmap image (RAM)
+    Texture2D cubicmap = LoadTextureFromImage(imMap);       // Convert image to texture to display (VRAM)
+    Mesh mesh = GenMeshCubicmap(imMap, (Vector3){ 1.0f, 1.0f, 1.0f });
     Model model = LoadModelFromMesh(mesh);
-    UnloadImage(image);     // Unload cubesmap image from RAM, already uploaded to VRAM
     
     // NOTE: By default each cube is mapped to one part of texture atlas
     Texture2D texture = LoadTexture("resources/cubicmap_atlas.png");    // Load map texture
     model.materials[0].maps[MAP_DIFFUSE].texture = texture;             // Set map diffuse texture
     
+    // Get map image data to be used for collision detection
+    Color *mapPixels = GetImageData(imMap);
+    UnloadImage(imMap);             // Unload image from RAM
+    
     Vector3 mapPosition = { -16.0f, 0.0f, -8.0f };  // Set model position
     Vector3 playerPosition = camera.position;       // Set player position
     
@@ -46,7 +49,39 @@ int main()
     {
         // Update
         //----------------------------------------------------------------------------------
+        Vector3 oldCamPos = camera.position;    // Store old camera position
+        
         UpdateCamera(&camera);      // Update camera
+        
+        // Check player collision (we simplify to 2D collision detection)
+        Vector2 playerPos = { camera.position.x, camera.position.z };
+        float playerRadius = 0.1f;  // Collision radius (player is modelled as a cilinder for collision)
+        
+        int playerCellX = (int)(playerPos.x - mapPosition.x + 0.5f);
+        int playerCellY = (int)(playerPos.y - mapPosition.z + 0.5f);
+        
+        // Out-of-limits security check
+        if (playerCellX < 0) playerCellX = 0;
+        else if (playerCellX >= cubicmap.width) playerCellX = cubicmap.width - 1;
+        
+        if (playerCellY < 0) playerCellY = 0;
+        else if (playerCellY >= cubicmap.height) playerCellY = cubicmap.height - 1;
+        
+        // Check map collisions using image data and player position
+        // TODO: Improvement: Just check player surrounding cells for collision
+        for (int y = 0; y < cubicmap.height; y++)
+        {
+            for (int x = 0; x < cubicmap.width; x++)
+            {
+                if ((mapPixels[y*cubicmap.width + x].r == 255) &&       // Collision: white pixel, only check R channel
+                    (CheckCollisionCircleRec(playerPos, playerRadius, 
+                    (Rectangle){ mapPosition.x - 0.5f + x*1.0f, mapPosition.z - 0.5f + y*1.0f, 1.0f, 1.0f })))
+                {
+                    // Collision detected, reset camera position
+                    camera.position = oldCamPos;
+                }
+            }
+        }
         //----------------------------------------------------------------------------------
 
         // Draw
@@ -64,6 +99,9 @@ int main()
             
             DrawTextureEx(cubicmap, (Vector2){ GetScreenWidth() - cubicmap.width*4 - 20, 20 }, 0.0f, 4.0f, WHITE);
             DrawRectangleLines(GetScreenWidth() - cubicmap.width*4 - 20, 20, cubicmap.width*4, cubicmap.height*4, GREEN);
+            
+            // Draw player position radar
+            DrawRectangle(GetScreenWidth() - cubicmap.width*4 - 20 + playerCellX*4, 20 + playerCellY*4, 4, 4, RED);
 
             DrawFPS(10, 10);
 
@@ -73,6 +111,8 @@ int main()
 
     // De-Initialization
     //--------------------------------------------------------------------------------------
+    free(mapPixels);            // Unload color array
+    
     UnloadTexture(cubicmap);    // Unload cubicmap texture
     UnloadTexture(texture);     // Unload map texture
     UnloadModel(model);         // Unload map model