Added new physics example

New physics example to see AddForceAtPosition() behaviour applied to 5
rigidbodies.

examples/physics_rigidbody_force.c

@@ -0,0 +1,141 @@
+/*******************************************************************************************
+*
+*   raylib [physac] physics example - Rigidbody forces
+*
+*   This example has been created using raylib 1.3 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2014 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#define MAX_OBJECTS 5
+#define OBJECTS_OFFSET 150
+
+#define FORCE_INTENSITY 250.0f  // Customize by user
+#define FORCE_RADIUS 100        // Customize by user    
+
+int main()
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    int screenWidth = 800;
+    int screenHeight = 450;
+    
+    InitWindow(screenWidth, screenHeight, "raylib [physics] example - rigidbodies forces");
+    SetTargetFPS(60);   // Enable v-sync
+    InitPhysics();      // Initialize internal physics values   (max rigidbodies/colliders available: 1024)
+    
+    // Physics initialization
+    Physics worldPhysics = {true, false, (Vector2){0, -9.81f}};
+    
+    // Set internal physics settings
+    SetPhysics(worldPhysics);
+    
+    // Objects initialization
+    Transform objects[MAX_OBJECTS];
+    for(int i = 0; i < MAX_OBJECTS; i++)
+    {
+        objects[i] = (Transform){(Vector2){75 + OBJECTS_OFFSET * i, (screenHeight - 50) / 2}, 0.0f, (Vector2){50, 50}};
+        AddCollider(i, (Collider){true, RectangleCollider, (Rectangle){objects[i].position.x, objects[i].position.y, objects[i].scale.x, objects[i].scale.y}, 0});
+        AddRigidbody(i, (Rigidbody){true, 1.0f, (Vector2){0, 0}, (Vector2){0, 0}, false, false, true, 0.5f, 0.5f});
+    }
+    
+    // Floor initialization 
+    // NOTE: floor doesn't need a rigidbody because it's a static physic object, just a collider to collide with other dynamic colliders (with rigidbody)
+    Transform floor = (Transform){(Vector2){0, screenHeight * 0.8f}, 0.0f, (Vector2){screenWidth, screenHeight * 0.2f}};
+    AddCollider(MAX_OBJECTS, (Collider){true, RectangleCollider, (Rectangle){floor.position.x, floor.position.y, floor.scale.x, floor.scale.y}, 0});
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        
+        // Update object physics 
+        // NOTE: all physics detections and reactions are calculated in ApplyPhysics() function (You will live happier :D)
+        for(int i = 0; i < MAX_OBJECTS; i++)
+        {
+            ApplyPhysics(i, &objects[i].position);
+        }
+        
+        // Check foce button input
+        if(IsMouseButtonPressed(MOUSE_LEFT_BUTTON))
+        {
+            AddForceAtPosition(GetMousePosition(), FORCE_INTENSITY, FORCE_RADIUS);
+        }
+        
+        // Check debug mode toggle button input
+        if(IsKeyPressed(KEY_P))
+        {
+            // Update program physics value
+            worldPhysics.debug = !worldPhysics.debug;
+            
+            // Update internal physics value
+            SetPhysics(worldPhysics);
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+            
+            // Check if debug mode is enabled
+            if(worldPhysics.debug)
+            {
+                // Draw every internal physics stored collider if it is active (floor included)
+                for(int i = 0; i < MAX_OBJECTS + 1; i++)
+                {
+                    if(GetCollider(i).enabled)
+                    {
+                        // Draw collider bounds
+                        DrawRectangleLines(GetCollider(i).bounds.x, GetCollider(i).bounds.y, GetCollider(i).bounds.width, GetCollider(i).bounds.height, GREEN);
+                        
+                        // Check if current collider is not floor
+                        if(i < MAX_OBJECTS)
+                        {
+                            // Draw lines between mouse position and objects if they are in force range
+                            if(CheckCollisionPointCircle(GetMousePosition(), (Vector2){GetCollider(i).bounds.x + GetCollider(i).bounds.width / 2, GetCollider(i).bounds.y + GetCollider(i).bounds.height / 2}, FORCE_RADIUS))
+                            {
+                                DrawLineV(GetMousePosition(), (Vector2){GetCollider(i).bounds.x + GetCollider(i).bounds.width / 2, GetCollider(i).bounds.y + GetCollider(i).bounds.height / 2}, RED);
+                            }
+                        }
+                    }
+                }
+                
+                // Draw radius circle
+                DrawCircleLines(GetMousePosition().x, GetMousePosition().y, FORCE_RADIUS, RED);
+            }
+            else
+            {
+                // Draw objects
+                for(int i = 0; i < MAX_OBJECTS; i++)
+                {
+                    DrawRectangleRec((Rectangle){objects[i].position.x, objects[i].position.y, objects[i].scale.x, objects[i].scale.y}, GRAY);
+                }
+                
+                // Draw floor
+                DrawRectangleRec((Rectangle){floor.position.x, floor.position.y, floor.scale.x, floor.scale.y}, BLACK);
+            }
+            
+                        
+            // Draw help messages
+            DrawText("Use LEFT MOUSE BUTTON to create a force in mouse position", (screenWidth - MeasureText("Use LEFT MOUSE BUTTON to create a force in mouse position", 20)) / 2, screenHeight * 0.20f, 20, LIGHTGRAY);
+            DrawText("Use P to switch DEBUG MODE", (screenWidth - MeasureText("Use P to switch DEBUG MODE", 20)) / 2, screenHeight * 0.3f, 20, LIGHTGRAY);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------   
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}