diff --git a/core/src/main/java/net/momirealms/craftengine/core/plugin/entityculling/EntityCulling.java b/core/src/main/java/net/momirealms/craftengine/core/plugin/entityculling/EntityCulling.java index fe190845b..2b16695bf 100644 --- a/core/src/main/java/net/momirealms/craftengine/core/plugin/entityculling/EntityCulling.java +++ b/core/src/main/java/net/momirealms/craftengine/core/plugin/entityculling/EntityCulling.java @@ -11,22 +11,33 @@ import net.momirealms.craftengine.core.world.collision.AABB; import java.util.Arrays; public final class EntityCulling { + public static final int MAX_SAMPLES = 14; private final Player player; private final int maxDistance; private final double aabbExpansion; - private final boolean[] dotSelectors = new boolean[14]; - private final MutableVec3d[] targetPoints = new MutableVec3d[14]; - + private final boolean[] dotSelectors = new boolean[MAX_SAMPLES]; + private final MutableVec3d[] targetPoints = new MutableVec3d[MAX_SAMPLES]; + private final int[] lastHitBlock = new int[MAX_SAMPLES * 3]; + private final boolean[] canCheckLastHitBlock = new boolean[MAX_SAMPLES]; + private int hitBlockCount = 0; + private int lastVisitChunkX = Integer.MAX_VALUE; + private int lastVisitChunkZ = Integer.MAX_VALUE; + private ClientChunk lastVisitChunk = null; + public EntityCulling(Player player, int maxDistance, double aabbExpansion) { this.player = player; this.maxDistance = maxDistance; this.aabbExpansion = aabbExpansion; - for (int i = 0; i < this.targetPoints.length; i++) { + for (int i = 0; i < MAX_SAMPLES; i++) { this.targetPoints[i] = new MutableVec3d(0,0,0); } } public boolean isVisible(AABB aabb, Vec3d cameraPos) { + // 情空标志位 + Arrays.fill(this.canCheckLastHitBlock, false); + this.hitBlockCount = 0; + // 根据AABB获取能包裹此AABB的最小长方体 int minX = MiscUtils.floor(aabb.minX - this.aabbExpansion); int minY = MiscUtils.floor(aabb.minY - this.aabbExpansion); @@ -105,18 +116,59 @@ public final class EntityCulling { return isVisible(cameraPos, this.targetPoints, size); } + /** + * 检测射线与轴对齐边界框(AABB)是否相交 + * 使用slab方法进行射线-AABB相交检测 + */ + private boolean rayIntersection(int x, int y, int z, Vec3d rayOrigin, MutableVec3d rayDirection) { + // 计算射线方向的倒数，避免除法运算 + // 这对于处理射线方向分量为0的情况很重要 + MutableVec3d inverseRayDirection = new MutableVec3d(1, 1, 1).divide(rayDirection); + + // 计算射线与边界框各对面（slab）的相交参数 + // 对于每个轴，计算射线进入和退出该轴对应两个平面的时间 + double tMinX = (x - rayOrigin.x) * inverseRayDirection.x; + double tMaxX = (x + 1 - rayOrigin.x) * inverseRayDirection.x; + double tMinY = (y - rayOrigin.y) * inverseRayDirection.y; + double tMaxY = (y + 1 - rayOrigin.y) * inverseRayDirection.y; + double tMinZ = (z - rayOrigin.z) * inverseRayDirection.z; + double tMaxZ = (z + 1 - rayOrigin.z) * inverseRayDirection.z; + + // 计算射线进入边界框的最大时间（最近进入点） + // 需要取各轴进入时间的最大值，因为射线必须进入所有轴的范围内 + double tEntry = Math.max(Math.max(Math.min(tMinX, tMaxX), Math.min(tMinY, tMaxY)), Math.min(tMinZ, tMaxZ)); + + // 计算射线退出边界框的最短时间（最早退出点） + // 需要取各轴退出时间的最小值，因为射线一旦退出任一轴的范围就离开了边界框 + double tExit = Math.min(Math.min(Math.max(tMinX, tMaxX), Math.max(tMinY, tMaxY)), Math.max(tMinZ, tMaxZ)); + + // 如果最早退出时间大于0，说明整个边界框在射线起点后面 + // 这种情况我们视为不相交，因为通常我们只关心射线前方的相交 + if (tExit > 0) { + return false; + } + + // 如果进入时间大于退出时间，说明没有有效的相交区间 + // 这发生在射线完全错过边界框的情况下 + // 满足以下条件说明射线与边界框相交： + // 1. 进入时间 <= 退出时间（存在有效相交区间） + // 2. 退出时间 <= 0（边界框至少有一部分在射线起点前方或包含起点） + return tEntry <= tExit; + } + /** * 使用3D DDA算法检测从起点到多个目标点的视线是否通畅 * 算法基于数字微分分析，遍历射线路径上的所有方块 */ private boolean isVisible(Vec3d start, MutableVec3d[] targets, int targetCount) { + // 起点所在方块的整数坐标（世界坐标转换为方块坐标） int startBlockX = MiscUtils.floor(start.x); int startBlockY = MiscUtils.floor(start.y); int startBlockZ = MiscUtils.floor(start.z); // 遍历所有目标点进行视线检测 - for (int targetIndex = 0; targetIndex < targetCount; targetIndex++) { + outer: for (int targetIndex = 0; targetIndex < targetCount; targetIndex++) { MutableVec3d currentTarget = targets[targetIndex]; // 计算起点到目标的相对向量（世界坐标差） @@ -124,6 +176,18 @@ public final class EntityCulling { double deltaY = start.y - currentTarget.y; double deltaZ = start.z - currentTarget.z; + // 检查之前命中的方块，大概率还是命中 + for (int i = 0; i < MAX_SAMPLES; i++) { + if (this.canCheckLastHitBlock[i]) { + int offset = i * 3; + if (rayIntersection(this.lastHitBlock[offset], this.lastHitBlock[offset + 1], this.lastHitBlock[offset + 2], start, new MutableVec3d(deltaX, deltaY, deltaZ).normalize())) { + continue outer; + } + } else { + break; + } + } + // 计算相对向量的绝对值，用于确定各方向上的距离 double absDeltaX = Math.abs(deltaX); double absDeltaY = Math.abs(deltaY); @@ -205,6 +269,8 @@ public final class EntityCulling { // 如果当前目标点可见立即返回 if (isLineOfSightClear) { return true; + } else { + this.canCheckLastHitBlock[this.hitBlockCount++] = true; } } @@ -222,6 +288,9 @@ public final class EntityCulling { // 检查当前方块是否遮挡视线 if (isOccluding(currentBlockX, currentBlockY, currentBlockZ)) { + this.lastHitBlock[this.hitBlockCount * 3] = currentBlockX; + this.lastHitBlock[this.hitBlockCount * 3 + 1] = currentBlockY; + this.lastHitBlock[this.hitBlockCount * 3 + 2] = currentBlockZ; return false; // 视线被遮挡，立即返回 } @@ -258,13 +327,30 @@ public final class EntityCulling { } private boolean isOccluding(int x, int y, int z) { - ClientChunk trackedChunk = this.player.getTrackedChunk(ChunkPos.asLong(x >> 4, z >> 4)); + int chunkX = x >> 4; + int chunkZ = z >> 4; + ClientChunk trackedChunk; + // 使用上次记录的值，比每次走hash都更快 + if (chunkX == this.lastVisitChunkX && chunkZ == this.lastVisitChunkZ) { + trackedChunk = this.lastVisitChunk; + } else { + trackedChunk = this.player.getTrackedChunk(ChunkPos.asLong(chunkX, chunkZ)); + this.lastVisitChunk = trackedChunk; + this.lastVisitChunkX = chunkX; + this.lastVisitChunkZ = chunkZ; + } if (trackedChunk == null) { return false; } return trackedChunk.isOccluding(x, y, z); } + public void removeLastVisitChunkIfMatches(int chunkX, int chunkZ) { + if (this.lastVisitChunk != null && this.lastVisitChunkX == chunkX && this.lastVisitChunkZ == chunkZ) { + this.lastVisitChunk = null; + } + } + private enum Relative { INSIDE, POSITIVE, NEGATIVE; public static Relative from(int min, int max, double pos) {