Perfectly elastic collisions
Quan1umMango opened this issue · 0 comments
Quan1umMango commented
I'm trying to achieve perfectly elastic collisions by setting the restitution of the ball and the floor to 1 in the restitution example but the ball does not behave elastically. Each time it bounces less than the previous height. I'm wondering how else can I achieve the effect?
Heres the code, although it's a slight modification of the example:
#include "raylib.h"
#define PHYSAC_IMPLEMENTATION
#include "physac.h"
int main()
{
// Initialization
//--------------------------------------------------------------------------------------
int screenWidth = 800;
int screenHeight = 450;
SetConfigFlags(FLAG_MSAA_4X_HINT);
InitWindow(screenWidth, screenHeight, "[physac] - Restitution demo");
// Physac logo drawing position
int logoX = screenWidth - MeasureText("Physac", 30) - 10;
int logoY = 15;
// Initialize physics and default physics bodies
InitPhysics();
// Create floor rectangle physics body
PhysicsBody floor = CreatePhysicsBodyRectangle((Vector2){ screenWidth/2, screenHeight }, screenWidth, 100, 10);
floor->enabled = false; // Disable body state to convert it to static (no dynamics, but collisions)
floor->restitution = 1;
// Create circles physics body
PhysicsBody circleA = CreatePhysicsBodyCircle((Vector2){ screenWidth*0.5f, screenHeight/2 }, 30, 10);
circleA->restitution = 1.0f;
SetTargetFPS(60);
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
// ...
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(BLACK);
DrawFPS(screenWidth - 90, screenHeight - 30);
// Draw created physics bodies
int bodiesCount = GetPhysicsBodiesCount();
for (int i = 0; i < bodiesCount; i++)
{
PhysicsBody body = GetPhysicsBody(i);
int vertexCount = GetPhysicsShapeVerticesCount(i);
for (int j = 0; j < vertexCount; j++)
{
// Get physics bodies shape vertices to draw lines
// Note: GetPhysicsShapeVertex() already calculates rotation transformations
Vector2 vertexA = GetPhysicsShapeVertex(body, j);
int jj = (((j + 1) < vertexCount) ? (j + 1) : 0); // Get next vertex or first to close the shape
Vector2 vertexB = GetPhysicsShapeVertex(body, jj);
DrawLineV(vertexA, vertexB, GREEN); // Draw a line between two vertex positions
}
}
DrawText("Restitution amount", (screenWidth - MeasureText("Restitution amount", 30))/2, 75, 30, WHITE);
DrawText("100%", circleA->position.x - MeasureText("100%", 20)/2, circleA->position.y - 7, 20, WHITE);
DrawText("Physac", logoX, logoY, 30, WHITE);
DrawText("Powered by", logoX + 50, logoY - 7, 10, WHITE);
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
ClosePhysics(); // Unitialize physics
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}