Begin particle registry impl

src/api/java/net/caffeinemc/mods/sodium/api/buffer/UnmanagedBufferBuilder.java

@@ -38,8 +38,16 @@ public void push(MemoryStack ignoredStack, long src, int size) {
         byteOffset += size;
     }
 
+    public Built build() {
+        return new Built(this.byteOffset, MemoryUtil.memSlice(this.buffer, 0, this.byteOffset));
+    }
+
+    public void reset() {
+        this.byteOffset = 0;
+    }
+
     /**
-     * Resets this builder.
+     * Builds and resets this builder.
      * Make sure to use/upload the return value before pushing more data.
      * @return a ByteBuffer containing all the data pushed to this builder
      */

src/main/java/me/jellysquid/mods/sodium/client/gl/buffer/GlBufferTexture.java

@@ -21,13 +21,15 @@ public GlBufferTexture() {
         this.glBufferHandle = GlStateManager._glGenBuffers();
     }
 
-    public void uploadData(ByteBuffer data, int size) {
+    public void putData(ByteBuffer data, int offset, int size) {
+        int neededSize = offset + size;
         GL31.glBindBuffer(GL31.GL_TEXTURE_BUFFER, this.glBufferHandle);
-        if (size > this.bufferSize) {
+
+        if (neededSize > this.bufferSize) {
             RenderSystem.glBufferData(GL31.GL_TEXTURE_BUFFER, data, GlConst.GL_DYNAMIC_DRAW);
-            this.bufferSize = size;
+            this.bufferSize = neededSize;
         } else {
-            GL15.glBufferSubData(GL31.GL_TEXTURE_BUFFER, 0, data);
+            GL15.glBufferSubData(GL31.GL_TEXTURE_BUFFER, offset, data);
         }
     }
 

src/main/java/me/jellysquid/mods/sodium/client/render/texture/ParticleTextureRegistry.java

@@ -0,0 +1,35 @@
+package me.jellysquid.mods.sodium.client.render.texture;
+
+import it.unimi.dsi.fastutil.floats.FloatFloatImmutablePair;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+
+public class ParticleTextureRegistry {
+    private final Object2IntOpenHashMap<FloatFloatImmutablePair> uvToIndex = new Object2IntOpenHashMap<>();
+
+    private ArrayList<FloatFloatImmutablePair> toAdd = new ArrayList<>();
+
+    private int currentIndex = 0;
+
+    public int get(float u, float v) {
+        FloatFloatImmutablePair key = new FloatFloatImmutablePair(u, v);
+        return uvToIndex.computeIfAbsent(key, pairKey -> {
+            toAdd.add((FloatFloatImmutablePair) pairKey);
+            return currentIndex++;
+        });
+    }
+
+    public boolean isDirty() {
+        return !toAdd.isEmpty();
+    }
+
+    public List<FloatFloatImmutablePair> flushUpdates() {
+        var ret = this.toAdd;
+        this.toAdd = new ArrayList<>();
+        return ret;
+    }
+}

src/main/java/me/jellysquid/mods/sodium/mixin/features/render/particle/ParticleManagerMixin.java

@@ -88,6 +88,9 @@ public abstract class ParticleManagerMixin {
     @Unique
     private UnmanagedBufferBuilder particleBuffer;
 
+    @Unique
+    private UnmanagedBufferBuilder particleTextureBuffer;
+
     @Unique
     private GlBufferTexture bufferTexture;
 
@@ -98,6 +101,7 @@ public abstract class ParticleManagerMixin {
     private void postInit(ClientWorld world, TextureManager textureManager, CallbackInfo ci) {
         this.glVertexArray = GlStateManager._glGenVertexArrays();
         this.particleBuffer = new UnmanagedBufferBuilder(1);
+        this.particleTextureBuffer = new UnmanagedBufferBuilder(1);
         this.bufferTexture = new GlBufferTexture();
         this.renderView = new ParticleRenderView(world);
     }
@@ -265,7 +269,7 @@ private void bindDummyVao() {
     @Unique
     private void uploadParticleBuffer() {
         UnmanagedBufferBuilder.Built particleData = this.particleBuffer.end();
-        this.bufferTexture.uploadData(particleData.buffer, particleData.size);
+        this.bufferTexture.putData(particleData.buffer, 0, particleData.size);
     }
 
     @Inject(method = "setWorld", at = @At("RETURN"))