Enuf enums

- Remove GlVersioned abstraction in favor of explicit fallback
- Remove versioned.BufferStorage

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

@@ -73,7 +73,7 @@ public class GlVertexArray extends GlObject {
 			offsets[index] = startOffset;
 			strides[index] = stride;
 
-			GlCompat.vertexArray.setupAttrib(handle(), stride, vbo, startOffset, attribute, index);
+			GlCompat.vertexArray.setupAttrib(handle(), index, vbo, stride, startOffset, attribute);
 
 			startOffset += attribute.getByteWidth();
 		}

src/main/java/com/jozufozu/flywheel/gl/versioned/BufferStorage.java

@@ -1,46 +0,0 @@
-package com.jozufozu.flywheel.gl.versioned;
-
-import org.lwjgl.opengl.ARBBufferStorage;
-import org.lwjgl.opengl.GL44;
-import org.lwjgl.opengl.GLCapabilities;
-
-import com.jozufozu.flywheel.gl.buffer.GlBufferType;
-
-public enum BufferStorage implements GlVersioned {
-
-	GL44CORE {
-		@Override
-		public boolean supported(GLCapabilities caps) {
-			return caps.OpenGL44;
-		}
-
-		@Override
-		public void bufferStorage(GlBufferType target, long size, int flags) {
-			GL44.glBufferStorage(target.glEnum, size, flags);
-		}
-	},
-	ARB {
-		@Override
-		public boolean supported(GLCapabilities caps) {
-			return caps.GL_ARB_buffer_storage;
-		}
-
-		@Override
-		public void bufferStorage(GlBufferType target, long size, int flags) {
-			ARBBufferStorage.glBufferStorage(target.glEnum, size, flags);
-		}
-	},
-	UNSUPPORTED {
-		@Override
-		public boolean supported(GLCapabilities caps) {
-			return true;
-		}
-
-		@Override
-		public void bufferStorage(GlBufferType target, long size, int flags) {
-			throw new UnsupportedOperationException();
-		}
-	};
-
-	public abstract void bufferStorage(GlBufferType target, long size, int flags);
-}

src/main/java/com/jozufozu/flywheel/gl/versioned/GlCompat.java

@@ -1,7 +1,6 @@
 package com.jozufozu.flywheel.gl.versioned;
 
 import java.nio.ByteBuffer;
-import java.util.Optional;
 
 import org.lwjgl.PointerBuffer;
 import org.lwjgl.opengl.GL;
@@ -20,14 +19,12 @@ import net.minecraft.Util;
 public class GlCompat {
 	private static final GLCapabilities caps;
 	public static final VertexArray vertexArray;
-	public static final BufferStorage bufferStorage;
 	public static final boolean amd;
 	public static final boolean supportsIndirect;
 
 	static {
 		caps = GL.createCapabilities();
-		bufferStorage = getLatest(BufferStorage.class);
+		vertexArray = VertexArray.DSA.INSTANCE.fallback(caps);
-		vertexArray = getLatest(VertexArray.class);
 		supportsIndirect = _decideIfWeSupportIndirect();
 		amd = _decideIfWeAreAMDWindows();
 	}
@@ -40,7 +37,7 @@ public class GlCompat {
 	}
 
 	public static boolean supportsInstancing() {
-		return vertexArray != VertexArray.UNSUPPORTED;
+		return caps.OpenGL33 || caps.GL_ARB_instanced_arrays;
 	}
 
 	public static boolean supportsIndirect() {
@@ -56,23 +53,6 @@ public class GlCompat {
 				caps.GL_ARB_direct_state_access);
 	}
 
-	/**
-	 * Get the most compatible version of a specific OpenGL feature by iterating over enum constants in order.
-	 *
-	 * @param <V>   The type of the versioning enum.
-	 * @param clazz The class of the versioning enum.
-	 * @return The first defined enum variant to return true.
-	 */
-	private static <V extends Enum<V> & GlVersioned> V getLatest(Class<V> clazz) {
-		for (V it : clazz.getEnumConstants()) {
-			if (it.supported(GlCompat.caps)) {
-				return Optional.of(it)
-						.get();
-			}
-		}
-		throw new IllegalStateException("Invalid versioned enum, must provide at least one supported constant");
-	}
-
 	/**
 	 * Modified from:
 	 * <br> <a href="https://github.com/grondag/canvas/commit/820bf754092ccaf8d0c169620c2ff575722d7d96">canvas</a>

src/main/java/com/jozufozu/flywheel/gl/versioned/GlVersioned.java

@@ -1,17 +0,0 @@
-package com.jozufozu.flywheel.gl.versioned;
-
-import org.lwjgl.opengl.GLCapabilities;
-
-/**
- * This interface should be implemented by enums such that the
- * last defined variant <em>always</em> returns {@code true}
- */
-public interface GlVersioned {
-	/**
-	 * Queries whether this variant is supported by the current system.
-	 *
-	 * @param caps The {@link GLCapabilities} reported by the current system.
-	 * @return <code>true</code> if this variant is supported, or if this is the last defined variant.
-	 */
-	boolean supported(GLCapabilities caps);
-}

src/main/java/com/jozufozu/flywheel/gl/versioned/VertexArray.java

@@ -1,24 +1,98 @@
 package com.jozufozu.flywheel.gl.versioned;
 
 import org.lwjgl.opengl.ARBInstancedArrays;
-import org.lwjgl.opengl.GL30;
+import org.lwjgl.opengl.GL20C;
-import org.lwjgl.opengl.GL33;
+import org.lwjgl.opengl.GL30C;
+import org.lwjgl.opengl.GL33C;
 import org.lwjgl.opengl.GL45C;
 import org.lwjgl.opengl.GLCapabilities;
+import org.lwjgl.system.Checks;
 
 import com.jozufozu.flywheel.gl.GlStateTracker;
 import com.jozufozu.flywheel.gl.array.VertexAttribute;
 import com.jozufozu.flywheel.gl.buffer.GlBufferType;
 import com.mojang.blaze3d.platform.GlStateManager;
 
-public enum VertexArray implements GlVersioned {
+public interface VertexArray {
-	DSA {
+	int create();
+
+	void setElementBuffer(int vao, int elementBuffer);
+
+	void setupAttrib(int vao, int index, int vbo, int stride, long offset, VertexAttribute attribute);
+
+	void setAttribDivisor(int vao, int attrib, int divisor);
+
+	abstract class GL3 implements VertexArray {
 		@Override
-		public boolean supported(GLCapabilities caps) {
+		public int create() {
-			// The static methods from GL45 and ARBDirectStateAccess all point to GL45C.
+			return GL30C.glGenVertexArrays();
-			return caps.OpenGL45 || caps.GL_ARB_direct_state_access;
 		}
 
+		@Override
+		public void setElementBuffer(int vao, int elementBuffer) {
+			if (vao != GlStateTracker.getVertexArray()) {
+				GlStateManager._glBindVertexArray(vao);
+			}
+			GlBufferType.ELEMENT_ARRAY_BUFFER.bind(elementBuffer);
+		}
+
+		@Override
+		public void setupAttrib(int vao, int index, int vbo, int stride, long offset, VertexAttribute attribute) {
+			if (vao != GlStateTracker.getVertexArray()) {
+				GlStateManager._glBindVertexArray(vao);
+			}
+			GlBufferType.ARRAY_BUFFER.bind(vbo);
+
+			GL20C.glEnableVertexAttribArray(index);
+			attribute.setup(offset, index, stride);
+		}
+
+	}
+
+	class InstancedArraysARB extends GL3 {
+		public static InstancedArraysARB INSTANCE = new InstancedArraysARB();
+
+		@Override
+		public void setAttribDivisor(int vao, int attrib, int divisor) {
+			if (vao != GlStateTracker.getVertexArray()) {
+				GlStateManager._glBindVertexArray(vao);
+			}
+			ARBInstancedArrays.glVertexAttribDivisorARB(attrib, divisor);
+		}
+
+		public VertexArray fallback(GLCapabilities caps) {
+			return isSupported(caps) ? this : null;
+		}
+
+		private boolean isSupported(GLCapabilities caps) {
+			return Checks.checkFunctions(caps.glVertexAttribDivisorARB);
+		}
+	}
+
+	class InstancedArraysCore extends GL3 {
+		public static InstancedArraysCore INSTANCE = new InstancedArraysCore();
+
+		@Override
+		public void setAttribDivisor(int vao, int attrib, int divisor) {
+			if (vao != GlStateTracker.getVertexArray()) {
+				GlStateManager._glBindVertexArray(vao);
+			}
+			GL33C.glVertexAttribDivisor(attrib, divisor);
+		}
+
+		public VertexArray fallback(GLCapabilities caps) {
+			return isSupported(caps) ? this : InstancedArraysARB.INSTANCE.fallback(caps);
+		}
+
+		private static boolean isSupported(GLCapabilities caps) {
+			// We know vertex arrays are supported because minecraft required GL32.
+			return Checks.checkFunctions(caps.glVertexAttribDivisor);
+		}
+	}
+
+	class DSA implements VertexArray {
+		public static final DSA INSTANCE = new DSA();
+
 		@Override
 		public int create() {
 			return GL45C.glCreateVertexArrays();
@@ -30,7 +104,7 @@ public enum VertexArray implements GlVersioned {
 		}
 
 		@Override
-		public void setupAttrib(int vao, int stride, int vbo, long offset, VertexAttribute attribute, int index) {
+		public void setupAttrib(int vao, int index, int vbo, int stride, long offset, VertexAttribute attribute) {
 			GL45C.glEnableVertexArrayAttrib(vao, index);
 			GL45C.glVertexArrayVertexBuffer(vao, index, vbo, offset, stride);
 			attribute.setupDSA(vao, index);
@@ -40,115 +114,13 @@ public enum VertexArray implements GlVersioned {
 		public void setAttribDivisor(int vao, int attrib, int divisor) {
 			GL45C.glVertexArrayBindingDivisor(vao, attrib, divisor);
 		}
-	},
+
-	GL_33 {
+		public VertexArray fallback(GLCapabilities caps) {
-		@Override
+			return isSupported(caps) ? this : InstancedArraysCore.INSTANCE.fallback(caps);
-		public boolean supported(GLCapabilities caps) {
-			return caps.OpenGL33;
 		}
 
-		@Override
+		private static boolean isSupported(GLCapabilities caps) {
-		public int create() {
+			return Checks.checkFunctions(caps.glCreateVertexArrays, caps.glVertexArrayElementBuffer, caps.glEnableVertexArrayAttrib, caps.glVertexArrayVertexBuffer, caps.glVertexArrayBindingDivisor, caps.glVertexArrayAttribFormat, caps.glVertexArrayAttribIFormat);
-			return GL33.glGenVertexArrays();
 		}
-
+	}
-		@Override
-		public void setElementBuffer(int vao, int elementBuffer) {
-			if (vao != GlStateTracker.getVertexArray()) {
-				GlStateManager._glBindVertexArray(vao);
-			}
-			GlBufferType.ELEMENT_ARRAY_BUFFER.bind(elementBuffer);
-		}
-
-		@Override
-		public void setupAttrib(int vao, int stride, int vbo, long offset, VertexAttribute attribute, int index) {
-			if (vao != GlStateTracker.getVertexArray()) {
-				GlStateManager._glBindVertexArray(vao);
-			}
-			GlBufferType.ARRAY_BUFFER.bind(vbo);
-
-			GL33.glEnableVertexAttribArray(index);
-			attribute.setup(offset, index, stride);
-		}
-
-		@Override
-		public void setAttribDivisor(int vao, int attrib, int divisor) {
-			if (vao != GlStateTracker.getVertexArray()) {
-				GlStateManager._glBindVertexArray(vao);
-			}
-			GL33.glVertexAttribDivisor(attrib, divisor);
-		}
-	},
-	ARB_INSTANCED_ARRAYS {
-		@Override
-		public boolean supported(GLCapabilities caps) {
-			return caps.GL_ARB_instanced_arrays;
-		}
-
-		@Override
-		public int create() {
-			return GL30.glGenVertexArrays();
-		}
-
-		@Override
-		public void setElementBuffer(int vao, int elementBuffer) {
-			if (vao != GlStateTracker.getVertexArray()) {
-				GlStateManager._glBindVertexArray(vao);
-			}
-			GlBufferType.ELEMENT_ARRAY_BUFFER.bind(elementBuffer);
-		}
-
-		@Override
-		public void setupAttrib(int vao, int stride, int vbo, long offset, VertexAttribute attribute, int index) {
-			if (vao != GlStateTracker.getVertexArray()) {
-				GlStateManager._glBindVertexArray(vao);
-			}
-			GlBufferType.ARRAY_BUFFER.bind(vbo);
-
-			GL30.glEnableVertexAttribArray(index);
-			attribute.setup(offset, index, stride);
-		}
-
-		@Override
-		public void setAttribDivisor(int vao, int attrib, int divisor) {
-			if (vao != GlStateTracker.getVertexArray()) {
-				GlStateManager._glBindVertexArray(vao);
-			}
-			ARBInstancedArrays.glVertexAttribDivisorARB(attrib, divisor);
-		}
-	},
-	UNSUPPORTED {
-		@Override
-		public boolean supported(GLCapabilities caps) {
-			return true;
-		}
-
-		@Override
-		public int create() {
-			throw new UnsupportedOperationException("Cannot use vertex arrays");
-		}
-
-		@Override
-		public void setElementBuffer(int vao, int elementBuffer) {
-			throw new UnsupportedOperationException("Cannot use vertex arrays");
-		}
-
-		@Override
-		public void setupAttrib(int vao, int stride, int vbo, long offset, VertexAttribute attribute, int index) {
-			throw new UnsupportedOperationException("Cannot use vertex arrays");
-		}
-
-		@Override
-		public void setAttribDivisor(int vao, int attrib, int divisor) {
-			throw new UnsupportedOperationException("Cannot use vertex arrays");
-		}
-	};
-
-	public abstract int create();
-
-	public abstract void setElementBuffer(int vao, int elementBuffer);
-
-	public abstract void setupAttrib(int vao, int stride, int vbo, long offset, VertexAttribute attribute, int index);
-
-	public abstract void setAttribDivisor(int vao, int attrib, int divisor);
 }