diff --git a/src/physac.h b/src/physac.h index 6a90dc29e..dd2b1628f 100644 --- a/src/physac.h +++ b/src/physac.h @@ -146,7 +146,7 @@ typedef struct PhysicBodyData { // Module Functions Declaration //---------------------------------------------------------------------------------- PHYSACDEF void InitPhysics(Vector2 gravity); // Initializes pointers array (just pointers, fixed size) -PHYSACDEF void UpdatePhysics(); // Update physic objects, calculating physic behaviours and collisions detection +PHYSACDEF void UpdatePhysics(double deltaTime); // Update physic objects, calculating physic behaviours and collisions detection PHYSACDEF void ClosePhysics(); // Unitialize all physic objects and empty the objects pool PHYSACDEF PhysicBody CreatePhysicBody(Vector2 position, float rotation, Vector2 scale); // Create a new physic body dinamically, initialize it and add to pool @@ -182,7 +182,7 @@ PHYSACDEF Rectangle TransformToRectangle(Transform transform); // Defines and Macros //---------------------------------------------------------------------------------- #define MAX_PHYSIC_BODIES 256 // Maximum available physic bodies slots in bodies pool -#define PHYSICS_STEPS 64 // Physics update steps per frame for improved collision-detection +#define PHYSICS_TIMESTEP 0.016666 // Physics fixed time step (1/fps) #define PHYSICS_ACCURACY 0.0001f // Velocity subtract operations round filter (friction) #define PHYSICS_ERRORPERCENT 0.001f // Collision resolve position fix @@ -218,376 +218,367 @@ PHYSACDEF void InitPhysics(Vector2 gravity) } // Update physic objects, calculating physic behaviours and collisions detection -PHYSACDEF void UpdatePhysics() +PHYSACDEF void UpdatePhysics(double deltaTime) { - // Reset all physic objects is grounded state - for (int i = 0; i < physicBodiesCount; i++) physicBodies[i]->rigidbody.isGrounded = false; - - for (int steps = 0; steps < PHYSICS_STEPS; steps++) + for (int i = 0; i < physicBodiesCount; i++) { - for (int i = 0; i < physicBodiesCount; i++) + if (physicBodies[i]->enabled) { - if (physicBodies[i]->enabled) + // Update physic behaviour + if (physicBodies[i]->rigidbody.enabled) { - // Update physic behaviour - if (physicBodies[i]->rigidbody.enabled) + // Apply friction to acceleration in X axis + if (physicBodies[i]->rigidbody.acceleration.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x -= physicBodies[i]->rigidbody.friction*deltaTime; + else if (physicBodies[i]->rigidbody.acceleration.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x += physicBodies[i]->rigidbody.friction*deltaTime; + else physicBodies[i]->rigidbody.acceleration.x = 0.0f; + + // Apply friction to acceleration in Y axis + if (physicBodies[i]->rigidbody.acceleration.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y -= physicBodies[i]->rigidbody.friction*deltaTime; + else if (physicBodies[i]->rigidbody.acceleration.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y += physicBodies[i]->rigidbody.friction*deltaTime; + else physicBodies[i]->rigidbody.acceleration.y = 0.0f; + + // Apply friction to velocity in X axis + if (physicBodies[i]->rigidbody.velocity.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x -= physicBodies[i]->rigidbody.friction*deltaTime; + else if (physicBodies[i]->rigidbody.velocity.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.friction*deltaTime; + else physicBodies[i]->rigidbody.velocity.x = 0.0f; + + // Apply friction to velocity in Y axis + if (physicBodies[i]->rigidbody.velocity.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y -= physicBodies[i]->rigidbody.friction*deltaTime; + else if (physicBodies[i]->rigidbody.velocity.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.friction*deltaTime; + else physicBodies[i]->rigidbody.velocity.y = 0.0f; + + // Apply gravity to velocity + if (physicBodies[i]->rigidbody.applyGravity) { - // Apply friction to acceleration in X axis - if (physicBodies[i]->rigidbody.acceleration.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else if (physicBodies[i]->rigidbody.acceleration.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.x += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else physicBodies[i]->rigidbody.acceleration.x = 0.0f; - - // Apply friction to acceleration in Y axis - if (physicBodies[i]->rigidbody.acceleration.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else if (physicBodies[i]->rigidbody.acceleration.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.acceleration.y += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else physicBodies[i]->rigidbody.acceleration.y = 0.0f; - - // Apply friction to velocity in X axis - if (physicBodies[i]->rigidbody.velocity.x > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else if (physicBodies[i]->rigidbody.velocity.x < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else physicBodies[i]->rigidbody.velocity.x = 0.0f; - - // Apply friction to velocity in Y axis - if (physicBodies[i]->rigidbody.velocity.y > PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y -= physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else if (physicBodies[i]->rigidbody.velocity.y < PHYSICS_ACCURACY) physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.friction/PHYSICS_STEPS; - else physicBodies[i]->rigidbody.velocity.y = 0.0f; - - // Apply gravity to velocity - if (physicBodies[i]->rigidbody.applyGravity) - { - physicBodies[i]->rigidbody.velocity.x += gravityForce.x/PHYSICS_STEPS; - physicBodies[i]->rigidbody.velocity.y += gravityForce.y/PHYSICS_STEPS; - } - - // Apply acceleration to velocity - physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.acceleration.x/PHYSICS_STEPS; - physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.acceleration.y/PHYSICS_STEPS; - - // Apply velocity to position - physicBodies[i]->transform.position.x += physicBodies[i]->rigidbody.velocity.x/PHYSICS_STEPS; - physicBodies[i]->transform.position.y -= physicBodies[i]->rigidbody.velocity.y/PHYSICS_STEPS; + physicBodies[i]->rigidbody.velocity.x += gravityForce.x*deltaTime; + physicBodies[i]->rigidbody.velocity.y += gravityForce.y*deltaTime; } - // Update collision detection - if (physicBodies[i]->collider.enabled) + // Apply acceleration to velocity + physicBodies[i]->rigidbody.velocity.x += physicBodies[i]->rigidbody.acceleration.x*deltaTime; + physicBodies[i]->rigidbody.velocity.y += physicBodies[i]->rigidbody.acceleration.y*deltaTime; + + // Apply velocity to position + physicBodies[i]->transform.position.x += physicBodies[i]->rigidbody.velocity.x*deltaTime; + physicBodies[i]->transform.position.y -= physicBodies[i]->rigidbody.velocity.y*deltaTime; + } + + // Update collision detection + if (physicBodies[i]->collider.enabled) + { + // Update collider bounds + physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform); + + // Check collision with other colliders + for (int k = 0; k < physicBodiesCount; k++) { - // Update collider bounds - physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform); - - // Check collision with other colliders - for (int k = 0; k < physicBodiesCount; k++) + if (physicBodies[k]->collider.enabled && i != k) { - if (physicBodies[k]->collider.enabled && i != k) + // Resolve physic collision + // NOTE: collision resolve is generic for all directions and conditions (no axis separated cases behaviours) + // and it is separated in rigidbody attributes resolve (velocity changes by impulse) and position correction (position overlap) + + // 1. Calculate collision normal + // ------------------------------------------------------------------------------------------------------------------------------------- + + // Define collision contact normal, direction and penetration depth + Vector2 contactNormal = { 0.0f, 0.0f }; + Vector2 direction = { 0.0f, 0.0f }; + float penetrationDepth = 0.0f; + + switch (physicBodies[i]->collider.type) { - // Resolve physic collision - // NOTE: collision resolve is generic for all directions and conditions (no axis separated cases behaviours) - // and it is separated in rigidbody attributes resolve (velocity changes by impulse) and position correction (position overlap) - - // 1. Calculate collision normal - // ------------------------------------------------------------------------------------------------------------------------------------- - - // Define collision contact normal, direction and penetration depth - Vector2 contactNormal = { 0.0f, 0.0f }; - Vector2 direction = { 0.0f, 0.0f }; - float penetrationDepth = 0.0f; - - switch (physicBodies[i]->collider.type) + case COLLIDER_RECTANGLE: { - case COLLIDER_RECTANGLE: + switch (physicBodies[k]->collider.type) { - switch (physicBodies[k]->collider.type) + case COLLIDER_RECTANGLE: { - case COLLIDER_RECTANGLE: + // Check if colliders are overlapped + if (CheckCollisionRecs(physicBodies[i]->collider.bounds, physicBodies[k]->collider.bounds)) { - // Check if colliders are overlapped - if (CheckCollisionRecs(physicBodies[i]->collider.bounds, physicBodies[k]->collider.bounds)) - { - // Calculate direction vector from i to k - direction.x = (physicBodies[k]->transform.position.x + physicBodies[k]->transform.scale.x/2) - (physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2); - direction.y = (physicBodies[k]->transform.position.y + physicBodies[k]->transform.scale.y/2) - (physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2); - - // Define overlapping and penetration attributes - Vector2 overlap; + // Calculate direction vector from i to k + direction.x = (physicBodies[k]->transform.position.x + physicBodies[k]->transform.scale.x/2) - (physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2); + direction.y = (physicBodies[k]->transform.position.y + physicBodies[k]->transform.scale.y/2) - (physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2); + + // Define overlapping and penetration attributes + Vector2 overlap; - // Calculate overlap on X axis - overlap.x = (physicBodies[i]->transform.scale.x + physicBodies[k]->transform.scale.x)/2 - abs(direction.x); - - // SAT test on X axis - if (overlap.x > 0.0f) - { - // Calculate overlap on Y axis - overlap.y = (physicBodies[i]->transform.scale.y + physicBodies[k]->transform.scale.y)/2 - abs(direction.y); - - // SAT test on Y axis - if (overlap.y > 0.0f) - { - // Find out which axis is axis of least penetration - if (overlap.y > overlap.x) - { - // Point towards k knowing that direction points from i to k - if (direction.x < 0.0f) contactNormal = (Vector2){ -1.0f, 0.0f }; - else contactNormal = (Vector2){ 1.0f, 0.0f }; - - // Update penetration depth for position correction - penetrationDepth = overlap.x; - } - else - { - // Point towards k knowing that direction points from i to k - if (direction.y < 0.0f) contactNormal = (Vector2){ 0.0f, 1.0f }; - else contactNormal = (Vector2){ 0.0f, -1.0f }; - - // Update penetration depth for position correction - penetrationDepth = overlap.y; - } - } - } - } - } break; - case COLLIDER_CIRCLE: - { - if (CheckCollisionCircleRec(physicBodies[k]->transform.position, physicBodies[k]->collider.radius, physicBodies[i]->collider.bounds)) + // Calculate overlap on X axis + overlap.x = (physicBodies[i]->transform.scale.x + physicBodies[k]->transform.scale.x)/2 - abs(direction.x); + + // SAT test on X axis + if (overlap.x > 0.0f) { - // Calculate direction vector between circles - direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2; - direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2; + // Calculate overlap on Y axis + overlap.y = (physicBodies[i]->transform.scale.y + physicBodies[k]->transform.scale.y)/2 - abs(direction.y); - // Calculate closest point on rectangle to circle - Vector2 closestPoint = { 0.0f, 0.0f }; - if (direction.x > 0.0f) closestPoint.x = physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width; - else closestPoint.x = physicBodies[i]->collider.bounds.x; - - if (direction.y > 0.0f) closestPoint.y = physicBodies[i]->collider.bounds.y + physicBodies[i]->collider.bounds.height; - else closestPoint.y = physicBodies[i]->collider.bounds.y; - - // Check if the closest point is inside the circle - if (CheckCollisionPointCircle(closestPoint, physicBodies[k]->transform.position, physicBodies[k]->collider.radius)) + // SAT test on Y axis + if (overlap.y > 0.0f) { - // Recalculate direction based on closest point position - direction.x = physicBodies[k]->transform.position.x - closestPoint.x; - direction.y = physicBodies[k]->transform.position.y - closestPoint.y; - float distance = Vector2Length(direction); - - // Calculate final contact normal - contactNormal.x = direction.x/distance; - contactNormal.y = -direction.y/distance; - - // Calculate penetration depth - penetrationDepth = physicBodies[k]->collider.radius - distance; - } - else - { - if (abs(direction.y) < abs(direction.x)) + // Find out which axis is axis of least penetration + if (overlap.y > overlap.x) { - // Calculate final contact normal - if (direction.y > 0.0f) - { - contactNormal = (Vector2){ 0.0f, -1.0f }; - penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y - physicBodies[k]->collider.radius); - } - else - { - contactNormal = (Vector2){ 0.0f, 1.0f }; - penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y + physicBodies[k]->collider.radius); - } + // Point towards k knowing that direction points from i to k + if (direction.x < 0.0f) contactNormal = (Vector2){ -1.0f, 0.0f }; + else contactNormal = (Vector2){ 1.0f, 0.0f }; + + // Update penetration depth for position correction + penetrationDepth = overlap.x; } else { - // Calculate final contact normal - if (direction.x > 0.0f) - { - contactNormal = (Vector2){ 1.0f, 0.0f }; - penetrationDepth = fabs(physicBodies[k]->transform.position.x + physicBodies[k]->collider.radius - physicBodies[i]->collider.bounds.x); - } - else - { - contactNormal = (Vector2){ -1.0f, 0.0f }; - penetrationDepth = fabs(physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width - physicBodies[k]->transform.position.x - physicBodies[k]->collider.radius); - } + // Point towards k knowing that direction points from i to k + if (direction.y < 0.0f) contactNormal = (Vector2){ 0.0f, 1.0f }; + else contactNormal = (Vector2){ 0.0f, -1.0f }; + + // Update penetration depth for position correction + penetrationDepth = overlap.y; } } } - } break; - } - } break; - case COLLIDER_CIRCLE: - { - switch (physicBodies[k]->collider.type) + } + } break; + case COLLIDER_CIRCLE: { - case COLLIDER_RECTANGLE: + if (CheckCollisionCircleRec(physicBodies[k]->transform.position, physicBodies[k]->collider.radius, physicBodies[i]->collider.bounds)) { - if (CheckCollisionCircleRec(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->collider.bounds)) + // Calculate direction vector between circles + direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x + physicBodies[i]->transform.scale.x/2; + direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y + physicBodies[i]->transform.scale.y/2; + + // Calculate closest point on rectangle to circle + Vector2 closestPoint = { 0.0f, 0.0f }; + if (direction.x > 0.0f) closestPoint.x = physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width; + else closestPoint.x = physicBodies[i]->collider.bounds.x; + + if (direction.y > 0.0f) closestPoint.y = physicBodies[i]->collider.bounds.y + physicBodies[i]->collider.bounds.height; + else closestPoint.y = physicBodies[i]->collider.bounds.y; + + // Check if the closest point is inside the circle + if (CheckCollisionPointCircle(closestPoint, physicBodies[k]->transform.position, physicBodies[k]->collider.radius)) { - // Calculate direction vector between circles - direction.x = physicBodies[k]->transform.position.x + physicBodies[i]->transform.scale.x/2 - physicBodies[i]->transform.position.x; - direction.y = physicBodies[k]->transform.position.y + physicBodies[i]->transform.scale.y/2 - physicBodies[i]->transform.position.y; - - // Calculate closest point on rectangle to circle - Vector2 closestPoint = { 0.0f, 0.0f }; - if (direction.x > 0.0f) closestPoint.x = physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width; - else closestPoint.x = physicBodies[k]->collider.bounds.x; - - if (direction.y > 0.0f) closestPoint.y = physicBodies[k]->collider.bounds.y + physicBodies[k]->collider.bounds.height; - else closestPoint.y = physicBodies[k]->collider.bounds.y; - - // Check if the closest point is inside the circle - if (CheckCollisionPointCircle(closestPoint, physicBodies[i]->transform.position, physicBodies[i]->collider.radius)) - { - // Recalculate direction based on closest point position - direction.x = physicBodies[i]->transform.position.x - closestPoint.x; - direction.y = physicBodies[i]->transform.position.y - closestPoint.y; - float distance = Vector2Length(direction); - - // Calculate final contact normal - contactNormal.x = direction.x/distance; - contactNormal.y = -direction.y/distance; - - // Calculate penetration depth - penetrationDepth = physicBodies[k]->collider.radius - distance; - } - else - { - if (abs(direction.y) < abs(direction.x)) - { - // Calculate final contact normal - if (direction.y > 0.0f) - { - contactNormal = (Vector2){ 0.0f, -1.0f }; - penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y - physicBodies[i]->collider.radius); - } - else - { - contactNormal = (Vector2){ 0.0f, 1.0f }; - penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y + physicBodies[i]->collider.radius); - } - } - else - { - // Calculate final contact normal and penetration depth - if (direction.x > 0.0f) - { - contactNormal = (Vector2){ 1.0f, 0.0f }; - penetrationDepth = fabs(physicBodies[i]->transform.position.x + physicBodies[i]->collider.radius - physicBodies[k]->collider.bounds.x); - } - else - { - contactNormal = (Vector2){ -1.0f, 0.0f }; - penetrationDepth = fabs(physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width - physicBodies[i]->transform.position.x - physicBodies[i]->collider.radius); - } - } - } - } - } break; - case COLLIDER_CIRCLE: - { - // Check if colliders are overlapped - if (CheckCollisionCircles(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->transform.position, physicBodies[k]->collider.radius)) - { - // Calculate direction vector between circles - direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x; - direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y; - - // Calculate distance between circles + // Recalculate direction based on closest point position + direction.x = physicBodies[k]->transform.position.x - closestPoint.x; + direction.y = physicBodies[k]->transform.position.y - closestPoint.y; float distance = Vector2Length(direction); - // Check if circles are not completely overlapped - if (distance != 0.0f) - { - // Calculate contact normal direction (Y axis needs to be flipped) - contactNormal.x = direction.x/distance; - contactNormal.y = -direction.y/distance; - } - else contactNormal = (Vector2){ 1.0f, 0.0f }; // Choose random (but consistent) values + // Calculate final contact normal + contactNormal.x = direction.x/distance; + contactNormal.y = -direction.y/distance; + + // Calculate penetration depth + penetrationDepth = physicBodies[k]->collider.radius - distance; } - } break; - default: break; - } - } break; - default: break; - } - - // Update rigidbody grounded state - if (physicBodies[i]->rigidbody.enabled) + else + { + if (abs(direction.y) < abs(direction.x)) + { + // Calculate final contact normal + if (direction.y > 0.0f) + { + contactNormal = (Vector2){ 0.0f, -1.0f }; + penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y - physicBodies[k]->collider.radius); + } + else + { + contactNormal = (Vector2){ 0.0f, 1.0f }; + penetrationDepth = fabs(physicBodies[i]->collider.bounds.y - physicBodies[k]->transform.position.y + physicBodies[k]->collider.radius); + } + } + else + { + // Calculate final contact normal + if (direction.x > 0.0f) + { + contactNormal = (Vector2){ 1.0f, 0.0f }; + penetrationDepth = fabs(physicBodies[k]->transform.position.x + physicBodies[k]->collider.radius - physicBodies[i]->collider.bounds.x); + } + else + { + contactNormal = (Vector2){ -1.0f, 0.0f }; + penetrationDepth = fabs(physicBodies[i]->collider.bounds.x + physicBodies[i]->collider.bounds.width - physicBodies[k]->transform.position.x - physicBodies[k]->collider.radius); + } + } + } + } + } break; + } + } break; + case COLLIDER_CIRCLE: { - if (contactNormal.y < 0.0f) physicBodies[i]->rigidbody.isGrounded = true; - } - - // 2. Calculate collision impulse - // ------------------------------------------------------------------------------------------------------------------------------------- - - // Calculate relative velocity - Vector2 relVelocity = { 0.0f, 0.0f }; - relVelocity.x = physicBodies[k]->rigidbody.velocity.x - physicBodies[i]->rigidbody.velocity.x; - relVelocity.y = physicBodies[k]->rigidbody.velocity.y - physicBodies[i]->rigidbody.velocity.y; - - // Calculate relative velocity in terms of the normal direction - float velAlongNormal = Vector2DotProduct(relVelocity, contactNormal); + switch (physicBodies[k]->collider.type) + { + case COLLIDER_RECTANGLE: + { + if (CheckCollisionCircleRec(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->collider.bounds)) + { + // Calculate direction vector between circles + direction.x = physicBodies[k]->transform.position.x + physicBodies[i]->transform.scale.x/2 - physicBodies[i]->transform.position.x; + direction.y = physicBodies[k]->transform.position.y + physicBodies[i]->transform.scale.y/2 - physicBodies[i]->transform.position.y; + + // Calculate closest point on rectangle to circle + Vector2 closestPoint = { 0.0f, 0.0f }; + if (direction.x > 0.0f) closestPoint.x = physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width; + else closestPoint.x = physicBodies[k]->collider.bounds.x; + + if (direction.y > 0.0f) closestPoint.y = physicBodies[k]->collider.bounds.y + physicBodies[k]->collider.bounds.height; + else closestPoint.y = physicBodies[k]->collider.bounds.y; + + // Check if the closest point is inside the circle + if (CheckCollisionPointCircle(closestPoint, physicBodies[i]->transform.position, physicBodies[i]->collider.radius)) + { + // Recalculate direction based on closest point position + direction.x = physicBodies[i]->transform.position.x - closestPoint.x; + direction.y = physicBodies[i]->transform.position.y - closestPoint.y; + float distance = Vector2Length(direction); + + // Calculate final contact normal + contactNormal.x = direction.x/distance; + contactNormal.y = -direction.y/distance; + + // Calculate penetration depth + penetrationDepth = physicBodies[k]->collider.radius - distance; + } + else + { + if (abs(direction.y) < abs(direction.x)) + { + // Calculate final contact normal + if (direction.y > 0.0f) + { + contactNormal = (Vector2){ 0.0f, -1.0f }; + penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y - physicBodies[i]->collider.radius); + } + else + { + contactNormal = (Vector2){ 0.0f, 1.0f }; + penetrationDepth = fabs(physicBodies[k]->collider.bounds.y - physicBodies[i]->transform.position.y + physicBodies[i]->collider.radius); + } + } + else + { + // Calculate final contact normal and penetration depth + if (direction.x > 0.0f) + { + contactNormal = (Vector2){ 1.0f, 0.0f }; + penetrationDepth = fabs(physicBodies[i]->transform.position.x + physicBodies[i]->collider.radius - physicBodies[k]->collider.bounds.x); + } + else + { + contactNormal = (Vector2){ -1.0f, 0.0f }; + penetrationDepth = fabs(physicBodies[k]->collider.bounds.x + physicBodies[k]->collider.bounds.width - physicBodies[i]->transform.position.x - physicBodies[i]->collider.radius); + } + } + } + } + } break; + case COLLIDER_CIRCLE: + { + // Check if colliders are overlapped + if (CheckCollisionCircles(physicBodies[i]->transform.position, physicBodies[i]->collider.radius, physicBodies[k]->transform.position, physicBodies[k]->collider.radius)) + { + // Calculate direction vector between circles + direction.x = physicBodies[k]->transform.position.x - physicBodies[i]->transform.position.x; + direction.y = physicBodies[k]->transform.position.y - physicBodies[i]->transform.position.y; + + // Calculate distance between circles + float distance = Vector2Length(direction); + + // Check if circles are not completely overlapped + if (distance != 0.0f) + { + // Calculate contact normal direction (Y axis needs to be flipped) + contactNormal.x = direction.x/distance; + contactNormal.y = -direction.y/distance; + } + else contactNormal = (Vector2){ 1.0f, 0.0f }; // Choose random (but consistent) values + } + } break; + default: break; + } + } break; + default: break; + } - // Dot not resolve if velocities are separating - if (velAlongNormal <= 0.0f) + // Update rigidbody grounded state + if (physicBodies[i]->rigidbody.enabled) physicBodies[i]->rigidbody.isGrounded = (contactNormal.y < 0.0f); + + // 2. Calculate collision impulse + // ------------------------------------------------------------------------------------------------------------------------------------- + + // Calculate relative velocity + Vector2 relVelocity = { 0.0f, 0.0f }; + relVelocity.x = physicBodies[k]->rigidbody.velocity.x - physicBodies[i]->rigidbody.velocity.x; + relVelocity.y = physicBodies[k]->rigidbody.velocity.y - physicBodies[i]->rigidbody.velocity.y; + + // Calculate relative velocity in terms of the normal direction + float velAlongNormal = Vector2DotProduct(relVelocity, contactNormal); + + // Dot not resolve if velocities are separating + if (velAlongNormal <= 0.0f) + { + // Calculate minimum bounciness value from both objects + float e = fminf(physicBodies[i]->rigidbody.bounciness, physicBodies[k]->rigidbody.bounciness); + + // Calculate impulse scalar value + float j = -(1.0f + e)*velAlongNormal; + j /= 1.0f/physicBodies[i]->rigidbody.mass + 1.0f/physicBodies[k]->rigidbody.mass; + + // Calculate final impulse vector + Vector2 impulse = { j*contactNormal.x, j*contactNormal.y }; + + // Calculate collision mass ration + float massSum = physicBodies[i]->rigidbody.mass + physicBodies[k]->rigidbody.mass; + float ratio = 0.0f; + + // Apply impulse to current rigidbodies velocities if they are enabled + if (physicBodies[i]->rigidbody.enabled) { - // Calculate minimum bounciness value from both objects - float e = fminf(physicBodies[i]->rigidbody.bounciness, physicBodies[k]->rigidbody.bounciness); + // Calculate inverted mass ration + ratio = physicBodies[i]->rigidbody.mass/massSum; - // Calculate impulse scalar value - float j = -(1.0f + e)*velAlongNormal; - j /= 1.0f/physicBodies[i]->rigidbody.mass + 1.0f/physicBodies[k]->rigidbody.mass; + // Apply impulse direction to velocity + physicBodies[i]->rigidbody.velocity.x -= impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); + physicBodies[i]->rigidbody.velocity.y -= impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); + } + + if (physicBodies[k]->rigidbody.enabled) + { + // Calculate inverted mass ration + ratio = physicBodies[k]->rigidbody.mass/massSum; - // Calculate final impulse vector - Vector2 impulse = { j*contactNormal.x, j*contactNormal.y }; + // Apply impulse direction to velocity + physicBodies[k]->rigidbody.velocity.x += impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); + physicBodies[k]->rigidbody.velocity.y += impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); + } + + // 3. Correct colliders overlaping (transform position) + // --------------------------------------------------------------------------------------------------------------------------------- + + // Calculate transform position penetration correction + Vector2 posCorrection; + posCorrection.x = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.x; + posCorrection.y = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.y; + + // Fix transform positions + if (physicBodies[i]->rigidbody.enabled) + { + // Fix physic objects transform position + physicBodies[i]->transform.position.x -= 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.x; + physicBodies[i]->transform.position.y += 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.y; - // Calculate collision mass ration - float massSum = physicBodies[i]->rigidbody.mass + physicBodies[k]->rigidbody.mass; - float ratio = 0.0f; + // Update collider bounds + physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform); - // Apply impulse to current rigidbodies velocities if they are enabled - if (physicBodies[i]->rigidbody.enabled) + if (physicBodies[k]->rigidbody.enabled) { - // Calculate inverted mass ration - ratio = physicBodies[i]->rigidbody.mass/massSum; - - // Apply impulse direction to velocity - physicBodies[i]->rigidbody.velocity.x -= impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); - physicBodies[i]->rigidbody.velocity.y -= impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); - } - - if (physicBodies[k]->rigidbody.enabled) - { - // Calculate inverted mass ration - ratio = physicBodies[k]->rigidbody.mass/massSum; - - // Apply impulse direction to velocity - physicBodies[k]->rigidbody.velocity.x += impulse.x*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); - physicBodies[k]->rigidbody.velocity.y += impulse.y*ratio*(1.0f+physicBodies[i]->rigidbody.bounciness); - } - - // 3. Correct colliders overlaping (transform position) - // --------------------------------------------------------------------------------------------------------------------------------- - - // Calculate transform position penetration correction - Vector2 posCorrection; - posCorrection.x = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.x; - posCorrection.y = penetrationDepth/((1.0f/physicBodies[i]->rigidbody.mass) + (1.0f/physicBodies[k]->rigidbody.mass))*PHYSICS_ERRORPERCENT*contactNormal.y; - - // Fix transform positions - if (physicBodies[i]->rigidbody.enabled) - { // Fix physic objects transform position - physicBodies[i]->transform.position.x -= 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.x; - physicBodies[i]->transform.position.y += 1.0f/physicBodies[i]->rigidbody.mass*posCorrection.y; + physicBodies[k]->transform.position.x += 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.x; + physicBodies[k]->transform.position.y -= 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.y; // Update collider bounds - physicBodies[i]->collider.bounds = TransformToRectangle(physicBodies[i]->transform); - - if (physicBodies[k]->rigidbody.enabled) - { - // Fix physic objects transform position - physicBodies[k]->transform.position.x += 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.x; - physicBodies[k]->transform.position.y -= 1.0f/physicBodies[k]->rigidbody.mass*posCorrection.y; - - // Update collider bounds - physicBodies[k]->collider.bounds = TransformToRectangle(physicBodies[k]->transform); - } + physicBodies[k]->collider.bounds = TransformToRectangle(physicBodies[k]->transform); } } }