diff --git a/examples/shapes/shapes_double_pendulum.c b/examples/shapes/shapes_double_pendulum.c index 85ca4af66..8cf0c5c68 100644 --- a/examples/shapes/shapes_double_pendulum.c +++ b/examples/shapes/shapes_double_pendulum.c @@ -22,12 +22,6 @@ //---------------------------------------------------------------------------------- // Macro Helpers //---------------------------------------------------------------------------------- -#define SCREEN_WIDTH 800 -#define SCREEN_HEIGHT 450 - -#define CENTER_X SCREEN_WIDTH * 0.5 -#define CENTER_Y SCREEN_HEIGHT * 0.5 - 100 - // Constant for Simulation #define SIMULATION_STEPS 30 #define G 9.81 @@ -45,32 +39,32 @@ int main(void) { // Initialization //-------------------------------------------------------------------------------------- + const int screenWidth = 800; + const int screenHeight = 450; + SetConfigFlags(FLAG_WINDOW_HIGHDPI); - InitWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "raylib [shapes] example - Double Pendulum"); + InitWindow(screenWidth, screenHeight, "raylib [shapes] example - double pendulum"); // Simulation Paramters - //-------------------------------------------------------------------------------------- float l1 = 15, m1 = 0.2, theta1 = DEG2RAD * 170, w1 = 0; float l2 = 15, m2 = 0.1, theta2 = DEG2RAD * 0, w2 = 0; float lengthScaler = 0.1; float totalM = m1 + m2; Vector2 previousPosition = CalculateDoublePendulumEndPoint(l1, theta1, l2, theta2); - previousPosition.x += CENTER_X; - previousPosition.y += CENTER_Y; + previousPosition.x += (screenWidth/2); + previousPosition.y += (screenHeight/2 - 100); // Scale length float L1 = l1 * lengthScaler; float L2 = l2 * lengthScaler; - // Draw Parameters - //-------------------------------------------------------------------------------------- + // Draw parameters int lineThick = 20, trailThick = 2; float fateAlpha = 0.01; - - // Create Framebuffer - //-------------------------------------------------------------------------------------- - RenderTexture2D target = LoadRenderTexture(SCREEN_WIDTH, SCREEN_HEIGHT); + + // Create framebuffer + RenderTexture2D target = LoadRenderTexture(screenWidth, screenHeight); SetTextureFilter(target.texture, TEXTURE_FILTER_BILINEAR); SetTargetFPS(60); @@ -80,60 +74,56 @@ int main(void) while (!WindowShouldClose()) // Detect window close button or ESC key { // Update + //---------------------------------------------------------------------------------- float dt = GetFrameTime(); float step = dt / SIMULATION_STEPS, step2 = step * step; // Update Physics - larger steps = better approximation - //---------------------------------------------------------------------------------- for (int i = 0; i < SIMULATION_STEPS; ++i) { float delta = theta1 - theta2; - float sinD = sin(delta), cosD = cos(delta), cos2D = cos(2 * delta); + float sinD = sinf(delta), cosD = cosf(delta), cos2D = cosf(2*delta); float ww1 = w1 * w1, ww2 = w2 * w2; // Calculate a1 - float a1 = (-G * (2 * m1 + m2) * sin(theta1) - - m2 * G * sin(theta1 - 2 * theta2) - - 2 * sinD * m2 * (ww2 * L2 + ww1 * L1 * cosD)) - / (L1 * (2 * m1 + m2 - m2 * cos2D)); + float a1 = (-G*(2*m1 + m2)*sinf(theta1) + - m2*G*sinf(theta1 - 2*theta2) + - 2*sinD*m2*(ww2*L2 + ww1*L1*cosD)) + / (L1*(2*m1 + m2 - m2*cos2D)); // Calculate a2 - float a2 = (2 * sinD * (ww1 * L1 * totalM - + G * totalM * cos(theta1) - + ww2 * L2 * m2 * cosD)) - / (L2 * (2 * m1 + m2 - m2 * cos2D)); + float a2 = (2*sinD*(ww1*L1*totalM + + G*totalM*cosf(theta1) + + ww2*L2*m2*cosD)) + / (L2*(2*m1 + m2 - m2*cos2D)); // Update thetas - theta1 += w1 * step + 0.5 * a1 * step2; - theta2 += w2 * step + 0.5 * a2 * step2; + theta1 += w1*step + 0.5f*a1*step2; + theta2 += w2*step + 0.5f*a2*step2; // Update omegas - w1 += a1 * step; - w2 += a2 * step; + w1 += a1*step; + w2 += a2*step; } - //---------------------------------------------------------------------------------- // Calculate position Vector2 currentPosition = CalculateDoublePendulumEndPoint(l1, theta1, l2, theta2); - currentPosition.x += CENTER_X; - currentPosition.y += CENTER_Y; + currentPosition.x += screenWidth/2; + currentPosition.y += screenHeight/2 - 100; - // Draw to framebuffer - //---------------------------------------------------------------------------------- + // Draw to render texture BeginTextureMode(target); - // Draw a transparent rectangle - smaller alpha = longer trails - DrawRectangle(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, Fade(BLACK, fateAlpha)); - + DrawRectangle(0, 0, screenWidth, screenHeight, Fade(BLACK, fateAlpha)); + // Draw trail DrawCircleV(previousPosition, trailThick, RED); DrawLineEx(previousPosition, currentPosition, trailThick * 2, RED); - EndTextureMode(); - //---------------------------------------------------------------------------------- // Update previous position previousPosition = currentPosition; + //---------------------------------------------------------------------------------- // Draw //---------------------------------------------------------------------------------- @@ -141,17 +131,16 @@ int main(void) ClearBackground(BLACK); - // Draw Trails Texture - DrawTextureRec(target.texture, (Rectangle){ 0, 0, target.texture.width, -target.texture.height }, - (Vector2){ 0, 0 }, WHITE); + // Draw trails texture + DrawTextureRec(target.texture, (Rectangle){ 0, 0, target.texture.width, -target.texture.height }, (Vector2){ 0, 0 }, WHITE); - // Draw Double Pendulum - DrawRectanglePro((Rectangle){ CENTER_X, CENTER_Y, 10 * l1, lineThick }, - (Vector2){0, lineThick * 0.5}, 90 - RAD2DEG * theta1, RAYWHITE); + // Draw double pendulum + DrawRectanglePro((Rectangle){ screenWidth/2, screenHeight/2 - 100, 10 * l1, lineThick }, + (Vector2){0, lineThick * 0.5}, 90 - RAD2DEG * theta1, RAYWHITE); Vector2 endpoint1 = CalculatePendulumEndPoint(l1, theta1); - DrawRectanglePro((Rectangle){ CENTER_X + endpoint1.x, CENTER_Y + endpoint1.y, 10 * l2, lineThick }, - (Vector2){0, lineThick * 0.5}, 90 - RAD2DEG * theta2, RAYWHITE); + DrawRectanglePro((Rectangle){ screenWidth/2 + endpoint1.x, screenHeight/2 - 100 + endpoint1.y, 10 * l2, lineThick }, + (Vector2){0, lineThick * 0.5}, 90 - RAD2DEG * theta2, RAYWHITE); EndDrawing(); //----------------------------------------------------------------------------------