Files
secretpsxsplash/src/collision.cpp
Jan Racek e51c06b012 hush
2026-03-24 13:01:47 +01:00

469 lines
16 KiB
C++

#include "collision.hh"
#include "scenemanager.hh"
#include <psyqo/fixed-point.hh>
// Helper type alias for brevity
using FP = psyqo::FixedPoint<12>;
namespace psxsplash {
// Static member initialization
psyqo::FixedPoint<12> SpatialGrid::WORLD_MIN = FP(-16);
psyqo::FixedPoint<12> SpatialGrid::WORLD_MAX = FP(16);
psyqo::FixedPoint<12> SpatialGrid::CELL_SIZE = FP(4); // (32 / 8) = 4
// AABB expand implementation
void AABB::expand(const psyqo::Vec3& delta) {
psyqo::FixedPoint<12> zero;
if (delta.x > zero) max.x = max.x + delta.x;
else min.x = min.x + delta.x;
if (delta.y > zero) max.y = max.y + delta.y;
else min.y = min.y + delta.y;
if (delta.z > zero) max.z = max.z + delta.z;
else min.z = min.z + delta.z;
}
// ============================================================================
// SpatialGrid Implementation
// ============================================================================
void SpatialGrid::clear() {
for (int i = 0; i < CELL_COUNT; i++) {
m_cells[i].count = 0;
}
}
void SpatialGrid::worldToGrid(const psyqo::Vec3& pos, int& gx, int& gy, int& gz) const {
// Clamp position to world bounds
auto px = pos.x;
auto py = pos.y;
auto pz = pos.z;
if (px < WORLD_MIN) px = WORLD_MIN;
if (px > WORLD_MAX) px = WORLD_MAX;
if (py < WORLD_MIN) py = WORLD_MIN;
if (py > WORLD_MAX) py = WORLD_MAX;
if (pz < WORLD_MIN) pz = WORLD_MIN;
if (pz > WORLD_MAX) pz = WORLD_MAX;
// Convert to grid coordinates (0 to GRID_SIZE-1)
// Using integer division after scaling
gx = ((px - WORLD_MIN) / CELL_SIZE).integer();
gy = ((py - WORLD_MIN) / CELL_SIZE).integer();
gz = ((pz - WORLD_MIN) / CELL_SIZE).integer();
// Clamp to valid range
if (gx < 0) gx = 0;
if (gx >= GRID_SIZE) gx = GRID_SIZE - 1;
if (gy < 0) gy = 0;
if (gy >= GRID_SIZE) gy = GRID_SIZE - 1;
if (gz < 0) gz = 0;
if (gz >= GRID_SIZE) gz = GRID_SIZE - 1;
}
int SpatialGrid::getCellIndex(const psyqo::Vec3& pos) const {
int gx, gy, gz;
worldToGrid(pos, gx, gy, gz);
return gx + gy * GRID_SIZE + gz * GRID_SIZE * GRID_SIZE;
}
void SpatialGrid::insert(uint16_t objectIndex, const AABB& bounds) {
// Get grid range for this AABB
int minGx, minGy, minGz;
int maxGx, maxGy, maxGz;
worldToGrid(bounds.min, minGx, minGy, minGz);
worldToGrid(bounds.max, maxGx, maxGy, maxGz);
// Insert into all overlapping cells
for (int gz = minGz; gz <= maxGz; gz++) {
for (int gy = minGy; gy <= maxGy; gy++) {
for (int gx = minGx; gx <= maxGx; gx++) {
int cellIndex = gx + gy * GRID_SIZE + gz * GRID_SIZE * GRID_SIZE;
Cell& cell = m_cells[cellIndex];
if (cell.count < MAX_OBJECTS_PER_CELL) {
cell.objectIndices[cell.count++] = objectIndex;
}
// If cell is full, object won't be in this cell (may miss collisions)
// This is a tradeoff for memory/performance
}
}
}
}
int SpatialGrid::queryAABB(const AABB& bounds, uint16_t* output, int maxResults) const {
int resultCount = 0;
// Get grid range for query AABB
int minGx, minGy, minGz;
int maxGx, maxGy, maxGz;
worldToGrid(bounds.min, minGx, minGy, minGz);
worldToGrid(bounds.max, maxGx, maxGy, maxGz);
// Track which objects we've already added (two 32-bit masks for objects 0-63)
uint32_t addedMaskLow = 0; // Objects 0-31
uint32_t addedMaskHigh = 0; // Objects 32-63
// Query all overlapping cells
for (int gz = minGz; gz <= maxGz; gz++) {
for (int gy = minGy; gy <= maxGy; gy++) {
for (int gx = minGx; gx <= maxGx; gx++) {
int cellIndex = gx + gy * GRID_SIZE + gz * GRID_SIZE * GRID_SIZE;
const Cell& cell = m_cells[cellIndex];
for (int i = 0; i < cell.count; i++) {
uint16_t objIndex = cell.objectIndices[i];
// Skip if already added (using bitmask for objects 0-63)
if (objIndex < 32) {
uint32_t bit = 1U << objIndex;
if (addedMaskLow & bit) continue;
addedMaskLow |= bit;
} else if (objIndex < 64) {
uint32_t bit = 1U << (objIndex - 32);
if (addedMaskHigh & bit) continue;
addedMaskHigh |= bit;
}
if (resultCount < maxResults) {
output[resultCount++] = objIndex;
}
}
}
}
}
return resultCount;
}
// ============================================================================
// CollisionSystem Implementation
// ============================================================================
void CollisionSystem::init() {
reset();
}
void CollisionSystem::reset() {
m_colliderCount = 0;
m_resultCount = 0;
m_triggerPairCount = 0;
m_grid.clear();
}
void CollisionSystem::registerCollider(uint16_t gameObjectIndex, const AABB& localBounds,
CollisionType type, CollisionMask mask) {
if (m_colliderCount >= MAX_COLLIDERS) {
// Out of collider slots
return;
}
CollisionData& data = m_colliders[m_colliderCount++];
data.bounds = localBounds; // Will be transformed in updateCollider
data.type = type;
data.layerMask = mask;
data.flags = 0;
data.gridCell = 0;
data.gameObjectIndex = gameObjectIndex;
}
void CollisionSystem::updateCollider(uint16_t gameObjectIndex, const psyqo::Vec3& position,
const psyqo::Matrix33& rotation) {
// Find the collider for this object
for (int i = 0; i < m_colliderCount; i++) {
if (m_colliders[i].gameObjectIndex == gameObjectIndex) {
// For now, just translate the AABB (no rotation support for AABBs)
// TODO: Compute rotated AABB if needed
// Store original local bounds somewhere if we need to recalculate
// For now, assume bounds are already world-relative
m_colliders[i].bounds.min = m_colliders[i].bounds.min + position;
m_colliders[i].bounds.max = m_colliders[i].bounds.max + position;
break;
}
}
}
int CollisionSystem::detectCollisions() {
m_resultCount = 0;
// Clear and rebuild spatial grid
m_grid.clear();
for (int i = 0; i < m_colliderCount; i++) {
m_grid.insert(i, m_colliders[i].bounds);
}
// Check each collider against potential colliders from grid
for (int i = 0; i < m_colliderCount; i++) {
const CollisionData& colliderA = m_colliders[i];
// Skip if no collision type
if (colliderA.type == CollisionType::None) continue;
// Query spatial grid for nearby objects
uint16_t nearby[32];
int nearbyCount = m_grid.queryAABB(colliderA.bounds, nearby, 32);
for (int j = 0; j < nearbyCount; j++) {
int otherIndex = nearby[j];
// Skip self
if (otherIndex == i) continue;
// Skip if already processed (only process pairs once)
if (otherIndex < i) continue;
const CollisionData& colliderB = m_colliders[otherIndex];
// Skip if no collision type
if (colliderB.type == CollisionType::None) continue;
// Check layer masks
if ((colliderA.layerMask & colliderB.layerMask) == 0) continue;
// Narrowphase AABB test
psyqo::Vec3 normal;
psyqo::FixedPoint<12> penetration;
if (testAABB(colliderA.bounds, colliderB.bounds, normal, penetration)) {
// Collision detected
if (m_resultCount < MAX_COLLISION_RESULTS) {
CollisionResult& result = m_results[m_resultCount++];
result.objectA = colliderA.gameObjectIndex;
result.objectB = colliderB.gameObjectIndex;
result.normal = normal;
result.penetration = penetration;
}
// Handle triggers
if (colliderA.type == CollisionType::Trigger) {
updateTriggerState(i, otherIndex, true);
}
if (colliderB.type == CollisionType::Trigger) {
updateTriggerState(otherIndex, i, true);
}
}
}
}
// Update trigger pairs that are no longer overlapping
for (int i = 0; i < m_triggerPairCount; i++) {
TriggerPair& pair = m_triggerPairs[i];
pair.framesSinceContact++;
// If no contact for several frames, trigger exit
if (pair.framesSinceContact > 2 && pair.state != 2) {
pair.state = 2; // Exiting
}
}
return m_resultCount;
}
bool CollisionSystem::testAABB(const AABB& a, const AABB& b,
psyqo::Vec3& normal, psyqo::FixedPoint<12>& penetration) const {
// Check for overlap on all axes
if (a.max.x < b.min.x || a.min.x > b.max.x) return false;
if (a.max.y < b.min.y || a.min.y > b.max.y) return false;
if (a.max.z < b.min.z || a.min.z > b.max.z) return false;
// Calculate penetration on each axis
auto overlapX1 = a.max.x - b.min.x;
auto overlapX2 = b.max.x - a.min.x;
auto overlapY1 = a.max.y - b.min.y;
auto overlapY2 = b.max.y - a.min.y;
auto overlapZ1 = a.max.z - b.min.z;
auto overlapZ2 = b.max.z - a.min.z;
// Find minimum overlap axis
auto minOverlapX = (overlapX1 < overlapX2) ? overlapX1 : overlapX2;
auto minOverlapY = (overlapY1 < overlapY2) ? overlapY1 : overlapY2;
auto minOverlapZ = (overlapZ1 < overlapZ2) ? overlapZ1 : overlapZ2;
// Constants for normals
const FP zero(0);
const FP one(1);
const FP negOne(-1);
// Determine separation axis (axis with least penetration)
if (minOverlapX <= minOverlapY && minOverlapX <= minOverlapZ) {
penetration = minOverlapX;
normal = psyqo::Vec3{(overlapX1 < overlapX2) ? negOne : one, zero, zero};
} else if (minOverlapY <= minOverlapZ) {
penetration = minOverlapY;
normal = psyqo::Vec3{zero, (overlapY1 < overlapY2) ? negOne : one, zero};
} else {
penetration = minOverlapZ;
normal = psyqo::Vec3{zero, zero, (overlapZ1 < overlapZ2) ? negOne : one};
}
return true;
}
void CollisionSystem::updateTriggerState(uint16_t triggerIndex, uint16_t otherIndex, bool isOverlapping) {
// Look for existing pair
for (int i = 0; i < m_triggerPairCount; i++) {
TriggerPair& pair = m_triggerPairs[i];
if (pair.triggerIndex == triggerIndex && pair.otherIndex == otherIndex) {
if (isOverlapping) {
pair.framesSinceContact = 0;
if (pair.state == 0) {
pair.state = 1; // Now staying
}
}
return;
}
}
// New pair - add it
if (isOverlapping && m_triggerPairCount < MAX_TRIGGERS) {
TriggerPair& pair = m_triggerPairs[m_triggerPairCount++];
pair.triggerIndex = triggerIndex;
pair.otherIndex = otherIndex;
pair.framesSinceContact = 0;
pair.state = 0; // New (enter event)
}
}
bool CollisionSystem::areColliding(uint16_t indexA, uint16_t indexB) const {
for (int i = 0; i < m_resultCount; i++) {
if ((m_results[i].objectA == indexA && m_results[i].objectB == indexB) ||
(m_results[i].objectA == indexB && m_results[i].objectB == indexA)) {
return true;
}
}
return false;
}
bool CollisionSystem::raycast(const psyqo::Vec3& origin, const psyqo::Vec3& direction,
psyqo::FixedPoint<12> maxDistance,
psyqo::Vec3& hitPoint, psyqo::Vec3& hitNormal,
uint16_t& hitObjectIndex) const {
// Simple brute-force raycast against all colliders
// TODO: Use spatial grid for optimization
auto closestT = maxDistance;
bool hit = false;
// Fixed-point constants
const FP zero(0);
const FP one(1);
const FP negOne(-1);
const FP largeVal(1000);
const FP negLargeVal(-1000);
FP epsilon;
epsilon.value = 4; // ~0.001 in 20.12 fixed point
for (int i = 0; i < m_colliderCount; i++) {
const CollisionData& collider = m_colliders[i];
if (collider.type == CollisionType::None) continue;
// Ray-AABB intersection test (slab method)
const AABB& box = collider.bounds;
auto tMin = negLargeVal;
auto tMax = largeVal;
// X slab
if (direction.x != zero) {
auto invD = one / direction.x;
auto t1 = (box.min.x - origin.x) * invD;
auto t2 = (box.max.x - origin.x) * invD;
if (t1 > t2) { auto tmp = t1; t1 = t2; t2 = tmp; }
if (t1 > tMin) tMin = t1;
if (t2 < tMax) tMax = t2;
} else if (origin.x < box.min.x || origin.x > box.max.x) {
continue;
}
// Y slab
if (direction.y != zero) {
auto invD = one / direction.y;
auto t1 = (box.min.y - origin.y) * invD;
auto t2 = (box.max.y - origin.y) * invD;
if (t1 > t2) { auto tmp = t1; t1 = t2; t2 = tmp; }
if (t1 > tMin) tMin = t1;
if (t2 < tMax) tMax = t2;
} else if (origin.y < box.min.y || origin.y > box.max.y) {
continue;
}
// Z slab
if (direction.z != zero) {
auto invD = one / direction.z;
auto t1 = (box.min.z - origin.z) * invD;
auto t2 = (box.max.z - origin.z) * invD;
if (t1 > t2) { auto tmp = t1; t1 = t2; t2 = tmp; }
if (t1 > tMin) tMin = t1;
if (t2 < tMax) tMax = t2;
} else if (origin.z < box.min.z || origin.z > box.max.z) {
continue;
}
if (tMin > tMax || tMax < zero) continue;
auto t = (tMin >= zero) ? tMin : tMax;
if (t < closestT && t >= zero) {
closestT = t;
hitObjectIndex = collider.gameObjectIndex;
hit = true;
// Calculate hit point
hitPoint = psyqo::Vec3{
origin.x + direction.x * t,
origin.y + direction.y * t,
origin.z + direction.z * t
};
// Calculate normal (which face was hit)
if ((hitPoint.x - box.min.x).abs() < epsilon) hitNormal = psyqo::Vec3{negOne, zero, zero};
else if ((hitPoint.x - box.max.x).abs() < epsilon) hitNormal = psyqo::Vec3{one, zero, zero};
else if ((hitPoint.y - box.min.y).abs() < epsilon) hitNormal = psyqo::Vec3{zero, negOne, zero};
else if ((hitPoint.y - box.max.y).abs() < epsilon) hitNormal = psyqo::Vec3{zero, one, zero};
else if ((hitPoint.z - box.min.z).abs() < epsilon) hitNormal = psyqo::Vec3{zero, zero, negOne};
else hitNormal = psyqo::Vec3{zero, zero, one};
}
}
return hit;
}
void CollisionSystem::processTriggerEvents(SceneManager& scene) {
// Process trigger pairs and fire Lua events
int writeIndex = 0;
for (int i = 0; i < m_triggerPairCount; i++) {
TriggerPair& pair = m_triggerPairs[i];
// Get game object indices
uint16_t triggerObjIdx = m_colliders[pair.triggerIndex].gameObjectIndex;
uint16_t otherObjIdx = m_colliders[pair.otherIndex].gameObjectIndex;
switch (pair.state) {
case 0: // Enter
scene.fireTriggerEnter(triggerObjIdx, otherObjIdx);
pair.state = 1; // Move to staying
m_triggerPairs[writeIndex++] = pair;
break;
case 1: // Staying
scene.fireTriggerStay(triggerObjIdx, otherObjIdx);
m_triggerPairs[writeIndex++] = pair;
break;
case 2: // Exit
scene.fireTriggerExit(triggerObjIdx, otherObjIdx);
// Don't copy - remove from list
break;
}
}
m_triggerPairCount = writeIndex;
}
} // namespace psxsplash