diff --git a/examples/shapes/shapes_ball_physics.c b/examples/shapes/shapes_ball_physics.c new file mode 100644 index 000000000..1c41d5f1a --- /dev/null +++ b/examples/shapes/shapes_ball_physics.c @@ -0,0 +1,222 @@ +/******************************************************************************************* +* +* raylib [shapes] example - physics bouncing balls +* +* Example complexity rating: [★★☆☆] 2/4 +* +* Example originally created with raylib 5.5 +* +* Example contributed by David Buzatto (@davidbuzatto) 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) 2025 David Buzatto (@davidbuzatto) +* +********************************************************************************************/ + +#include +#include +#include "raylib.h" + +#define MAX_BALLS 5000 // Maximum quantity of balls + +typedef struct Ball { + Vector2 pos; // Position + Vector2 vel; // Velocity + Vector2 ppos; // Previous position + float radius; + float friction; + float elasticity; + Color color; + bool grabbed; +} Ball; + +//------------------------------------------------------------------------------------ +// Program main entry point +//------------------------------------------------------------------------------------ +int main(void) +{ + // Initialization + //-------------------------------------------------------------------------------------- + const int screenWidth = 800; + const int screenHeight = 450; + + InitWindow(screenWidth, screenHeight, "raylib [shapes] example - physics bouncing balls"); + + Ball balls[MAX_BALLS] = {{ + .pos = {GetScreenWidth()/2, GetScreenHeight()/2}, + .vel = {200, 200}, + .ppos = {0}, + .radius = 40, + .friction = 0.99, + .elasticity = 0.9, + .color = BLUE, + .grabbed = false + }}; + + int ballQuantity = 1; + Ball *grabbedBall = NULL; // A pointer to the current ball that is grabbed + Vector2 pressOffset = {0}; // Mouse press offset relative to the ball that grabbedd + + float gravity = 100; // World gravity + + 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 + //---------------------------------------------------------------------------------- + float delta = GetFrameTime(); + Vector2 mousePos = GetMousePosition(); + + // Checks if a ball was grabbed + if (IsMouseButtonPressed(MOUSE_BUTTON_LEFT)) + { + for (int i = ballQuantity - 1; i >= 0; i--) { + + Ball *ball = &balls[i]; + pressOffset.x = mousePos.x - ball->pos.x; + pressOffset.y = mousePos.y - ball->pos.y; + + // If the distance between the ball position and the mouse press position + // is less or equal the ball radius, the event occured inside the ball + if (hypot(pressOffset.x, pressOffset.y) <= ball->radius) + { + ball->grabbed = true; + grabbedBall = ball; + break; + } + + } + } + + // Releases any ball the was grabbed + if (IsMouseButtonReleased(MOUSE_BUTTON_LEFT)) + { + if (grabbedBall != NULL) + { + grabbedBall->grabbed = false; + grabbedBall = NULL; + } + } + + // Creates a new ball + if (IsMouseButtonPressed(MOUSE_BUTTON_RIGHT) || (IsKeyDown(KEY_LEFT_CONTROL) && IsMouseButtonDown(MOUSE_BUTTON_RIGHT))) { + if (ballQuantity < MAX_BALLS) { + balls[ballQuantity++] = (Ball) { + .pos = mousePos, + .vel = {GetRandomValue(-300, 300), GetRandomValue(-300, 300)}, + .ppos = {0}, + .radius = 20 + GetRandomValue(0, 30), + .friction = 0.99, + .elasticity = 0.9, + .color = {GetRandomValue(0, 255), GetRandomValue(0, 255), GetRandomValue(0, 255), 255}, + .grabbed = false + }; + } + } + + // Shake balls + if (IsMouseButtonPressed(MOUSE_BUTTON_MIDDLE)) { + for (int i = 0; i < ballQuantity; i++) { + Ball *ball = &balls[i]; + if (!ball->grabbed) { + ball->vel = (Vector2) {GetRandomValue(-2000, 2000), GetRandomValue(-2000, 2000)}; + } + } + } + + // Changes gravity + gravity += GetMouseWheelMove() * 5; + + // Updates each ball state + for (int i = 0; i < ballQuantity; i++) { + + Ball *ball = &balls[i]; + + // The ball is not grabbed + if (!ball->grabbed) + { + // Ball repositioning using the velocity + ball->pos.x += ball->vel.x * delta; + ball->pos.y += ball->vel.y * delta; + + // Does the ball hit the screen right boundary? + if (ball->pos.x + ball->radius >= screenWidth) + { + ball->pos.x = screenWidth - ball->radius; // Ball repositioning + ball->vel.x = -ball->vel.x * ball->elasticity; // Elasticity makes the ball lose 10% of its velocity on hit + } + // Does the ball hit the screen left boundary? + else if (ball->pos.x - ball->radius <= 0) + { + ball->pos.x = ball->radius; + ball->vel.x = -ball->vel.x * ball->elasticity; + } + + // The same for y axis + if (ball->pos.y + ball->radius >= screenHeight) + { + ball->pos.y = screenHeight - ball->radius; + ball->vel.y = -ball->vel.y * ball->elasticity; + } + else if (ball->pos.y - ball->radius <= 0) + { + ball->pos.y = ball->radius; + ball->vel.y = -ball->vel.y * ball->elasticity; + } + + // Friction makes the ball lose 1% of its velocity each frame + ball->vel.x = ball->vel.x * ball->friction; + // Gravity affects only the y axis + ball->vel.y = ball->vel.y * ball->friction + gravity; + + } + else + { + // Ball repositioning using the mouse position + ball->pos.x = mousePos.x - pressOffset.x; + ball->pos.y = mousePos.y - pressOffset.y; + // While the ball is grabbed, recalculates its velocity + ball->vel.x = (ball->pos.x - ball->ppos.x) / delta; + ball->vel.y = (ball->pos.y - ball->ppos.y) / delta; + ball->ppos = ball->pos; + } + } + + //---------------------------------------------------------------------------------- + + // Draw + //---------------------------------------------------------------------------------- + BeginDrawing(); + + ClearBackground(RAYWHITE); + + for (int i = 0; i < ballQuantity; i++) + { + Ball *ball = &balls[i]; + DrawCircleV(ball->pos, ball->radius, ball->color); + DrawCircleLinesV(ball->pos, ball->radius, BLACK); + } + + DrawText("grab a ball by pressing with the mouse and throw it by releasing", 10, 10, 20, DARKGRAY); + DrawText("right click to create new balls (keep left control pressed to create a lot)", 10, 30, 20, DARKGRAY); + DrawText("use mouse wheel to change gravity", 10, 50, 20, DARKGRAY); + DrawText("middle click to shake", 10, 70, 20, DARKGRAY); + DrawText(TextFormat("ball quantity: %d", ballQuantity), 10, GetScreenHeight() - 55, 20, BLACK); + DrawText(TextFormat("gravity: %.2f", gravity), 10, GetScreenHeight() - 35, 20, BLACK); + + EndDrawing(); + //---------------------------------------------------------------------------------- + } + + // De-Initialization + //-------------------------------------------------------------------------------------- + CloseWindow(); // Close window and OpenGL context + //-------------------------------------------------------------------------------------- + + return 0; +} \ No newline at end of file diff --git a/examples/shapes/shapes_ball_physics.png b/examples/shapes/shapes_ball_physics.png new file mode 100644 index 000000000..1e4c86f14 Binary files /dev/null and b/examples/shapes/shapes_ball_physics.png differ