1 files changed, 140 insertions, 0 deletions
diff --git a/src/main/java/gregtech/common/misc/GTClientPollutionMap.java b/src/main/java/gregtech/common/misc/GTClientPollutionMap.java
new file mode 100644
index 0000000000..546f8e8d12
--- /dev/null
+++ b/src/main/java/gregtech/common/misc/GTClientPollutionMap.java
@@ -0,0 +1,140 @@
+package gregtech.common.misc;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.entity.EntityClientPlayerMP;
+import net.minecraft.util.MathHelper;
+
+public class GTClientPollutionMap {
+
+    private static final byte RADIUS = 24;
+    private static final byte DISTANCE_RELOAD_MAP = 5; // When player moved x chunks, shift the map to new center.
+    private static final byte SIZE = RADIUS * 2 + 1; // Area to keep stored.
+
+    private int x0, z0;
+    private int dim;
+
+    private boolean initialized = false;
+
+    private static short[][] chunkMatrix; // short because reasons.
+
+    public GTClientPollutionMap() {}
+
+    public void reset() {
+        initialized = false;
+    }
+
+    private void initialize(int playerChunkX, int playerChunkZ, int dimension) {
+        initialized = true;
+        chunkMatrix = new short[SIZE][SIZE];
+        x0 = playerChunkX;
+        z0 = playerChunkZ;
+        dim = dimension;
+    }
+
+    public void addChunkPollution(int chunkX, int chunkZ, int pollution) {
+        EntityClientPlayerMP player = Minecraft.getMinecraft().thePlayer;
+        if (player == null || player.worldObj == null) return;
+
+        int playerXChunk = MathHelper.floor_double(player.posX) >> 4;
+        int playerZChunk = MathHelper.floor_double(player.posZ) >> 4; // posX/Z seems to be always loaded,
+
+        if (!initialized) {
+            initialize(playerXChunk, playerZChunk, player.dimension);
+        }
+
+        if (dim != player.dimension) {
+            initialize(playerXChunk, playerZChunk, player.dimension);
+        }
+
+        if (Math.abs(x0 - playerXChunk) > DISTANCE_RELOAD_MAP || Math.abs(z0 - playerZChunk) > DISTANCE_RELOAD_MAP)
+            shiftCenter(playerXChunk, playerZChunk);
+
+        int relX = chunkX - x0 + RADIUS;
+        if (relX >= SIZE || relX < 0) // out of bounds
+            return;
+        int relZ = chunkZ - z0 + RADIUS;
+        if (relZ >= SIZE || relZ < 0) // out of bounds
+            return;
+
+        pollution = pollution / 225;
+        if (pollution > Short.MAX_VALUE) // Sanity
+            chunkMatrix[relX][relZ] = Short.MAX_VALUE; // Max pollution = 7,3mill
+        else if (pollution < 0) chunkMatrix[relX][relZ] = 0;
+        else chunkMatrix[relX][relZ] = (short) (pollution);
+    }
+
+    // xy interpolation, between 4 chunks as corners, unknown treated as 0.
+    public int getPollution(double fx, double fz) {
+        if (!initialized) return 0;
+        int x = MathHelper.floor_double(fx);
+        int z = MathHelper.floor_double(fz);
+        int xDiff = ((x - 8) >> 4) - x0;
+        int zDiff = ((z - 8) >> 4) - z0;
+
+        if (xDiff < -RADIUS || zDiff < -RADIUS || xDiff >= RADIUS || zDiff >= RADIUS) return 0;
+
+        // coordinates in shifted chunk.
+        x = (x - 8) % 16;
+        z = (z - 8) % 16;
+        if (x < 0) x = 16 + x;
+        if (z < 0) z = 16 + z;
+
+        int xi = 15 - x;
+        int zi = 15 - z;
+
+        // read pollution in 4 corner chunks
+        int offsetX = RADIUS + xDiff;
+        int offsetZ = RADIUS + zDiff;
+
+        int c00 = chunkMatrix[offsetX][offsetZ];
+        int c10 = chunkMatrix[offsetX + 1][offsetZ];
+        int c01 = chunkMatrix[offsetX][offsetZ + 1];
+        int c11 = chunkMatrix[offsetX + 1][offsetZ + 1];
+
+        // Is divided by 15*15 but is handled when storing chunk data.
+        return c00 * xi * zi + c10 * x * zi + c01 * xi * z + c11 * x * z;
+    }
+
+    // shift the matrix to fit new center
+    private void shiftCenter(int chunkX, int chunkZ) {
+        int xDiff = chunkX - x0;
+        int zDiff = chunkZ - z0;
+        boolean[] allEmpty = new boolean[SIZE]; // skip check z row if its empty.
+        if (xDiff > 0) for (byte x = 0; x < SIZE; x++) {
+            int xOff = x + xDiff;
+            if (xOff < SIZE) {
+                chunkMatrix[x] = chunkMatrix[xOff].clone();
+            } else {
+                chunkMatrix[x] = new short[SIZE];
+                allEmpty[x] = true;
+            }
+        }
+        else if (xDiff < 0) for (byte x = SIZE - 1; x >= 0; x--) {
+            int xOff = x + xDiff;
+            if (xOff > 0) {
+                chunkMatrix[x] = chunkMatrix[xOff].clone();
+            } else {
+                chunkMatrix[x] = new short[SIZE];
+                allEmpty[x] = true;
+            }
+        }
+
+        if (zDiff > 0) for (byte x = 0; x < SIZE; x++) {
+            if (allEmpty[x]) continue;
+            for (int z = 0; z < SIZE; z++) {
+                int zOff = z + zDiff;
+                chunkMatrix[x][z] = (zOff < SIZE) ? chunkMatrix[x][zOff] : 0;
+            }
+        }
+        else if (zDiff < 0) for (byte x = 0; x < SIZE; x++) {
+            if (allEmpty[x]) continue;
+            for (int z = SIZE - 1; z >= 0; z--) {
+                int zOff = z + zDiff;
+                chunkMatrix[x][z] = (zOff > 0) ? chunkMatrix[x][zOff] : 0;
+            }
+        }
+
+        x0 = chunkX;
+        z0 = chunkZ;
+    }
+}