GlBuffer tracks its size

- GlVertexArray#enableArrays

src/main/java/com/jozufozu/flywheel/backend/gl/GlVertexArray.java

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.backend.gl;
 
+import com.jozufozu.flywheel.util.AttribUtil;
 import com.mojang.blaze3d.platform.GlStateManager;
 
 public class GlVertexArray extends GlObject {
@@ -18,4 +19,8 @@ public class GlVertexArray extends GlObject {
 	protected void deleteInternal(int handle) {
 		GlStateManager._glDeleteVertexArrays(handle);
 	}
+
+	public void enableArrays(int count) {
+		AttribUtil.enableArrays(count);
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/GlBuffer.java

@@ -9,13 +9,6 @@ import com.jozufozu.flywheel.backend.gl.GlObject;
 
 public abstract class GlBuffer extends GlObject {
 
-	protected final GlBufferType type;
-
-	public GlBuffer(GlBufferType type) {
-		_create();
-		this.type = type;
-	}
-
 	/**
 	 * Request a Persistent mapped buffer.
 	 *
@@ -35,10 +28,63 @@ public abstract class GlBuffer extends GlObject {
 		}
 	}
 
-	public GlBufferType getBufferTarget() {
+	protected final GlBufferType type;
-		return type;
+
+	/**
+	 * The size (in bytes) of the buffer on the GPU.
+	 */
+	protected long capacity;
+
+	/**
+	 * How much extra room to give the buffer when we reallocate.
+	 */
+	protected int growthMargin;
+
+	public GlBuffer(GlBufferType type) {
+		_create();
+		this.type = type;
 	}
 
+	public void setGrowthMargin(int growthMargin) {
+		this.growthMargin = growthMargin;
+	}
+
+	public long getCapacity() {
+		return capacity;
+	}
+
+	public MappedBuffer getBuffer() {
+		return getBuffer(0, capacity);
+	}
+
+	public abstract MappedBuffer getBuffer(long offset, long length);
+
+	/**
+	 * Ensure that the buffer has at least enough room to store size bytes.
+	 *
+	 * @return true if the buffer grew.
+	 */
+	public boolean ensureCapacity(long size) {
+		if (size > capacity) {
+			capacity = size + growthMargin;
+			alloc(capacity);
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Call this after all draw calls using this buffer are complete.
+	 */
+	public void doneForThisFrame() {
+
+	}
+
+	protected abstract void alloc(long size);
+
+	public abstract void upload(ByteBuffer directBuffer);
+
 	public void bind() {
 		type.bind(handle());
 	}
@@ -47,16 +93,6 @@ public abstract class GlBuffer extends GlObject {
 		type.unbind();
 	}
 
-	public void doneForThisFrame() {
-
-	}
-
-	public abstract void alloc(long size);
-
-	public abstract void upload(ByteBuffer directBuffer);
-
-	public abstract MappedBuffer getBuffer(int offset, int length);
-
 	protected void _create() {
 		setHandle(GL20.glGenBuffers());
 	}

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/MappedGlBuffer.java

@@ -21,7 +21,7 @@ public class MappedGlBuffer extends GlBuffer implements Mappable {
 		this.usage = usage;
 	}
 
-	public void alloc(long size) {
+	protected void alloc(long size) {
 		GL15.glBufferData(type.glEnum, size, usage.glEnum);
 	}
 
@@ -29,7 +29,7 @@ public class MappedGlBuffer extends GlBuffer implements Mappable {
 		GL15.glBufferData(type.glEnum, directBuffer, usage.glEnum);
 	}
 
-	public MappedBuffer getBuffer(int offset, int length) {
+	public MappedBuffer getBuffer(long offset, long length) {
 		ByteBuffer byteBuffer = GL30.glMapBufferRange(type.glEnum, offset, length, GL30.GL_MAP_WRITE_BIT);
 
 		if (byteBuffer == null) {

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/PersistentGlBuffer.java

@@ -35,7 +35,7 @@ public class PersistentGlBuffer extends GlBuffer implements Mappable {
 	}
 
 	@Override
-	public void alloc(long size) {
+	protected void alloc(long size) {
 		this.size = size;
 
 		if (buffer != null) {
@@ -71,11 +71,11 @@ public class PersistentGlBuffer extends GlBuffer implements Mappable {
 	}
 
 	@Override
-	public MappedBuffer getBuffer(int offset, int length) {
+	public MappedBuffer getBuffer(long offset, long length) {
 
 		fence.waitSync();
 
-		buffer.position(offset);
+		buffer.position((int) offset);
 
 		return buffer;
 	}

src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/GPUInstancer.java

@@ -1,5 +1,7 @@
 package com.jozufozu.flywheel.backend.instancing.instancing;
 
+import org.lwjgl.system.MemoryUtil;
+
 import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.api.InstanceData;
 import com.jozufozu.flywheel.api.struct.Instanced;
@@ -10,12 +12,10 @@ import com.jozufozu.flywheel.core.layout.BufferLayout;
 import com.jozufozu.flywheel.backend.gl.buffer.GlBuffer;
 import com.jozufozu.flywheel.backend.gl.buffer.GlBufferType;
 import com.jozufozu.flywheel.backend.gl.buffer.MappedBuffer;
-import com.jozufozu.flywheel.backend.gl.error.GlError;
 import com.jozufozu.flywheel.backend.instancing.AbstractInstancer;
 import com.jozufozu.flywheel.backend.model.BufferedModel;
 import com.jozufozu.flywheel.backend.model.ModelAllocator;
 import com.jozufozu.flywheel.core.model.Model;
-import com.jozufozu.flywheel.util.AttribUtil;
 
 public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 
@@ -26,7 +26,6 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 	private BufferedModel model;
 	private GlVertexArray vao;
 	private GlBuffer instanceVBO;
-	private int glBufferSize = -1;
 	private int glInstanceCount = 0;
 	private boolean deleted;
 	private boolean initialized;
@@ -49,14 +48,11 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 		if (invalid()) return;
 
 		vao.bind();
-		GlError.pollAndThrow(() -> modelData.name() + "_bind");
 
 		renderSetup();
-		GlError.pollAndThrow(() -> modelData.name() + "_setup");
 
 		if (glInstanceCount > 0) {
 			model.drawInstances(glInstanceCount);
-			GlError.pollAndThrow(() -> modelData.name() + "_draw");
 		}
 
 		// persistent mapping sync point
@@ -83,7 +79,8 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 		vao.bind();
 
 		instanceVBO = GlBuffer.requestPersistent(GlBufferType.ARRAY_BUFFER);
-		AttribUtil.enableArrays(model.getAttributeCount() + instanceFormat.getAttributeCount());
+		instanceVBO.setGrowthMargin(instanceFormat.getStride() * 16);
+		vao.enableArrays(model.getAttributeCount() + instanceFormat.getAttributeCount());
 	}
 
 	public boolean isInitialized() {
@@ -135,10 +132,10 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 	private void clearBufferTail() {
 		int size = data.size();
 		final int offset = size * instanceFormat.getStride();
-		final int length = glBufferSize - offset;
+		final long length = instanceVBO.getCapacity() - offset;
 		if (length > 0) {
 			try (MappedBuffer buf = instanceVBO.getBuffer(offset, length)) {
-				buf.putByteArray(new byte[length]);
+				MemoryUtil.memSet(MemoryUtil.memAddress(buf.unwrap()), 0, length);
 			} catch (Exception e) {
 				Flywheel.log.error("Error clearing buffer tail:", e);
 			}
@@ -150,7 +147,7 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 
 		if (size <= 0) return;
 
-		try (MappedBuffer mapped = instanceVBO.getBuffer(0, glBufferSize)) {
+		try (MappedBuffer mapped = instanceVBO.getBuffer()) {
 
 			final StructWriter<D> writer = instancedType.getWriter(mapped);
 
@@ -170,11 +167,9 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 		int size = this.data.size();
 		int stride = instanceFormat.getStride();
 		int requiredSize = size * stride;
-		if (requiredSize > glBufferSize) {
+		if (instanceVBO.ensureCapacity(requiredSize)) {
-			glBufferSize = requiredSize + stride * 16;
-			instanceVBO.alloc(glBufferSize);
 
-			try (MappedBuffer buffer = instanceVBO.getBuffer(0, glBufferSize)) {
+			try (MappedBuffer buffer = instanceVBO.getBuffer()) {
 				StructWriter<D> writer = instancedType.getWriter(buffer);
 				for (D datum : data) {
 					writer.write(datum);

src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/InstancedMaterialGroup.java

@@ -59,7 +59,10 @@ public class InstancedMaterialGroup<P extends WorldProgram> implements MaterialG
 					.values();
 
 			// initialize all uninitialized instancers...
-			instancers.forEach(GPUInstancer::init);
+			for (GPUInstancer<?> gpuInstancer : instancers) {
+				gpuInstancer.init();
+			}
+
 			if (material.allocator instanceof ModelPool pool) {
 				// ...and then flush the model arena in case anything was marked for upload
 				pool.flush();
@@ -74,7 +77,9 @@ public class InstancedMaterialGroup<P extends WorldProgram> implements MaterialG
 
 			setup(program);
 
-			instancers.forEach(GPUInstancer::render);
+			for (GPUInstancer<?> instancer : instancers) {
+				instancer.render();
+			}
 		}
 	}
 

src/main/java/com/jozufozu/flywheel/backend/model/ArrayModelRenderer.java

@@ -36,12 +36,11 @@ public class ArrayModelRenderer extends ModelRenderer {
 		vao = new GlVertexArray();
 
 		vao.bind();
+		vao.enableArrays(this.model.getAttributeCount());
 
 		// bind the model's vbo to our vao
 		this.model.setupState();
 
-		AttribUtil.enableArrays(this.model.getAttributeCount());
-
 		GlVertexArray.unbind();
 
 		this.model.clearState();

src/main/java/com/jozufozu/flywheel/backend/model/ModelPool.java

@@ -25,7 +25,6 @@ public class ModelPool implements ModelAllocator {
 	private final List<PooledModel> pendingUpload = new ArrayList<>();
 
 	private final GlBuffer vbo;
-	private int bufferSize;
 
 	private int vertices;
 
@@ -34,12 +33,13 @@ public class ModelPool implements ModelAllocator {
 
 	public ModelPool(VertexType vertexType, int initialSize) {
 		this.vertexType = vertexType;
-		bufferSize = vertexType.getStride() * initialSize;
+		int stride = vertexType.getStride();
 
 		vbo = new MappedGlBuffer(GlBufferType.ARRAY_BUFFER);
 
 		vbo.bind();
-		vbo.alloc(bufferSize);
+		vbo.ensureCapacity((long) stride * initialSize);
+		vbo.setGrowthMargin(stride * 64);
 		vbo.unbind();
 	}
 
@@ -104,19 +104,11 @@ public class ModelPool implements ModelAllocator {
 	 * @return true if the buffer was reallocated
 	 */
 	private boolean realloc() {
-		int neededSize = vertices * vertexType.getStride();
+		return vbo.ensureCapacity((long) vertices * vertexType.getStride());
-		if (neededSize > bufferSize) {
-			bufferSize = neededSize + 128;
-			vbo.alloc(bufferSize);
-
-			return true;
-		}
-
-		return false;
 	}
 
 	private void uploadAll() {
-		try (MappedBuffer buffer = vbo.getBuffer(0, bufferSize)) {
+		try (MappedBuffer buffer = vbo.getBuffer()) {
 			VertexWriter writer = vertexType.createWriter(buffer.unwrap());
 
 			int vertices = 0;
@@ -134,7 +126,7 @@ public class ModelPool implements ModelAllocator {
 	}
 
 	private void uploadPending() {
-		try (MappedBuffer buffer = vbo.getBuffer(0, bufferSize)) {
+		try (MappedBuffer buffer = vbo.getBuffer()) {
 			VertexWriter writer = vertexType.createWriter(buffer.unwrap());
 			for (PooledModel model : pendingUpload) {
 				buffer(writer, model);

src/main/java/com/jozufozu/flywheel/backend/model/VBOModel.java

@@ -29,10 +29,10 @@ public class VBOModel implements BufferedModel {
 
 		vbo.bind();
 		// allocate the buffer on the gpu
-		vbo.alloc(model.size());
+		vbo.ensureCapacity(model.size());
 
-		// mirror it in system memory so we can write to it, and upload our model.
+		// mirror it in system memory, so we can write to it, and upload our model.
-		try (MappedBuffer buffer = vbo.getBuffer(0, model.size())) {
+		try (MappedBuffer buffer = vbo.getBuffer()) {
 			model.writeInto(buffer.unwrap());
 		} catch (Exception e) {
 			Flywheel.log.error(String.format("Error uploading model '%s':", model.name()), e);

src/main/java/com/jozufozu/flywheel/core/FullscreenQuad.java

@@ -32,8 +32,8 @@ public class FullscreenQuad {
 	private FullscreenQuad() {
 		vbo = new MappedGlBuffer(GlBufferType.ARRAY_BUFFER);
 		vbo.bind();
-		vbo.alloc(bufferSize);
+		vbo.ensureCapacity(bufferSize);
-		try (MappedBuffer buffer = vbo.getBuffer(0, bufferSize)) {
+		try (MappedBuffer buffer = vbo.getBuffer()) {
 			buffer.putFloatArray(vertices);
 		} catch (Exception e) {
 			Flywheel.log.error("Could not create fullscreen quad.", e);