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https://github.com/BX-Team/DivineMC.git
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more and more patches
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@@ -76,4 +76,9 @@ public class DivineWorldConfig {
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final Map<String, Object> value = DivineConfig.getMap("world-settings." + worldName + "." + path, null);
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return value.isEmpty() ? fallback : value;
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}
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public boolean saveFireworks = false;
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private void saveFireworks() {
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saveFireworks = getBoolean("gameplay-mechanics.should-save-fireworks", saveFireworks);
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}
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}
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@@ -0,0 +1,88 @@
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package space.bxteam.divinemc.util.lithium;
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import net.minecraft.util.Mth;
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/**
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* A replacement for the sine angle lookup table used in {@link Mth}, both reducing the size of LUT and improving
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* the access patterns for common paired sin/cos operations.
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* <p>
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* sin(-x) = -sin(x)
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* ... to eliminate negative angles from the LUT.
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* <p>
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* sin(x) = sin(pi/2 - x)
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* ... to eliminate supplementary angles from the LUT.
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* <p>
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* Using these identities allows us to reduce the LUT from 64K entries (256 KB) to just 16K entries (64 KB), enabling
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* it to better fit into the CPU's caches at the expense of some cycles on the fast path. The implementation has been
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* tightly optimized to avoid branching where possible and to use very quick integer operations.
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* <p>
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* Generally speaking, reducing the size of a lookup table is always a good optimization, but since we need to spend
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* extra CPU cycles trying to maintain parity with vanilla, there is the potential risk that this implementation ends
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* up being slower than vanilla when the lookup table is able to be kept in cache memory.
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* <p>
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* Unlike other "fast math" implementations, the values returned by this class are *bit-for-bit identical* with those
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* from {@link Mth}. Validation is performed during runtime to ensure that the table is correct.
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*
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* @author coderbot16 Author of the original (and very clever) <a href="https://gitlab.com/coderbot16/i73/-/tree/master/i73-trig/src">implementation</a> in Rust
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* @author jellysquid3 Additional optimizations, port to Java
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*/
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public class CompactSineLUT {
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private static final int[] SIN_INT = new int[16384 + 1];
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private static final float SIN_MIDPOINT;
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static {
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// Copy the sine table, covering to raw int bits
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for (int i = 0; i < SIN_INT.length; i++) {
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SIN_INT[i] = Float.floatToRawIntBits(Mth.SIN[i]);
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}
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SIN_MIDPOINT = Mth.SIN[Mth.SIN.length / 2];
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// Test that the lookup table is correct during runtime
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for (int i = 0; i < Mth.SIN.length; i++) {
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float expected = Mth.SIN[i];
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float value = lookup(i);
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if (expected != value) {
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throw new IllegalArgumentException(String.format("LUT error at index %d (expected: %s, found: %s)", i, expected, value));
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}
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}
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}
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// [VanillaCopy] Mth#sin(float)
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public static float sin(float f) {
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return lookup((int) (f * 10430.378f) & 0xFFFF);
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}
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// [VanillaCopy] Mth#cos(float)
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public static float cos(float f) {
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return lookup((int) (f * 10430.378f + 16384.0f) & 0xFFFF);
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}
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private static float lookup(int index) {
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// A special case... Is there some way to eliminate this?
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if (index == 32768) {
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return SIN_MIDPOINT;
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}
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// Trigonometric identity: sin(-x) = -sin(x)
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// Given a domain of 0 <= x <= 2*pi, just negate the value if x > pi.
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// This allows the sin table size to be halved.
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int neg = (index & 0x8000) << 16;
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// All bits set if (pi/2 <= x), none set otherwise
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// Extracts the 15th bit from 'half'
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int mask = (index << 17) >> 31;
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// Trigonometric identity: sin(x) = sin(pi/2 - x)
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int pos = (0x8001 & mask) + (index ^ mask);
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// Wrap the position in the table. Moving this down to immediately before the array access
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// seems to help the Hotspot compiler optimize the bit math better.
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pos &= 0x7fff;
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// Fetch the corresponding value from the LUT and invert the sign bit as needed
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// This directly manipulate the sign bit on the float bits to simplify logic
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return Float.intBitsToFloat(SIN_INT[pos] ^ neg);
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}
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}
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