A win for window sizes

- Fix transparent objects disappearing when the window is resized
- Clean up OitFramebuffer some more, add a quick description of each
  render pass
- Move oit noise factor to frame uniforms

common/src/backend/java/dev/engine_room/flywheel/backend/NoiseTextures.java

@@ -3,23 +3,23 @@ package dev.engine_room.flywheel.backend;
 import java.io.IOException;
 
 import org.jetbrains.annotations.UnknownNullability;
+import org.lwjgl.opengl.GL32;
 
 import com.mojang.blaze3d.platform.NativeImage;
+import com.mojang.blaze3d.systems.RenderSystem;
 
 import dev.engine_room.flywheel.api.Flywheel;
+import dev.engine_room.flywheel.backend.gl.GlTextureUnit;
 import net.minecraft.client.renderer.texture.DynamicTexture;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.ResourceManager;
 
 public class NoiseTextures {
-
-	public static final ResourceLocation NOISE_TEXTURE = Flywheel.rl("textures/flywheel/noise/blue/0.png");
-	public static final int NOISE_LAYERS = 16;
+	public static final ResourceLocation NOISE_TEXTURE = Flywheel.rl("textures/flywheel/noise/blue.png");
 
 	@UnknownNullability
 	public static DynamicTexture BLUE_NOISE;
 
-
 	public static void reload(ResourceManager manager) {
 		if (BLUE_NOISE != null) {
 			BLUE_NOISE.close();
@@ -36,6 +36,15 @@ public class NoiseTextures {
 			var image = NativeImage.read(NativeImage.Format.LUMINANCE, is);
 
 			BLUE_NOISE = new DynamicTexture(image);
+
+			GlTextureUnit.T0.makeActive();
+			BLUE_NOISE.bind();
+
+			NoiseTextures.BLUE_NOISE.setFilter(true, false);
+			RenderSystem.texParameter(GL32.GL_TEXTURE_2D, GL32.GL_TEXTURE_WRAP_S, GL32.GL_REPEAT);
+			RenderSystem.texParameter(GL32.GL_TEXTURE_2D, GL32.GL_TEXTURE_WRAP_T, GL32.GL_REPEAT);
+
+			RenderSystem.bindTexture(0);
 		} catch (IOException e) {
 
 		}

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectDrawManager.java

@@ -49,7 +49,7 @@ public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
 
 	private final DepthPyramid depthPyramid;
 
-	private final OitFramebuffer wboitFrameBuffer;
+	private final OitFramebuffer oitFramebuffer;
 
 	public IndirectDrawManager(IndirectPrograms programs) {
 		this.programs = programs;
@@ -66,7 +66,7 @@ public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
 
 		depthPyramid = new DepthPyramid(programs);
 
-		wboitFrameBuffer = new OitFramebuffer(programs);
+		oitFramebuffer = new OitFramebuffer(programs);
 	}
 
 	@Override
@@ -146,29 +146,32 @@ public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
 			group.submitSolid();
 		}
 
-		wboitFrameBuffer.depthRange();
+		oitFramebuffer.prepare();
+
+		oitFramebuffer.depthRange();
 
 		for (var group : cullingGroups.values()) {
 			group.submitTransparent(PipelineCompiler.OitMode.DEPTH_RANGE);
 		}
 
-		wboitFrameBuffer.renderTransmittance();
+		oitFramebuffer.renderTransmittance();
 
 		for (var group : cullingGroups.values()) {
 			group.submitTransparent(PipelineCompiler.OitMode.GENERATE_COEFFICIENTS);
 		}
 
-		wboitFrameBuffer.renderDepth();
+		oitFramebuffer.renderDepth();
 
+		// Need to bind this again because we just drew a full screen quad for OIT.
 		vertexArray.bindForDraw();
 
-		wboitFrameBuffer.shade();
+		oitFramebuffer.shade();
 
 		for (var group : cullingGroups.values()) {
 			group.submitTransparent(PipelineCompiler.OitMode.EVALUATE);
 		}
 
-		wboitFrameBuffer.composite();
+		oitFramebuffer.composite();
 
 		MaterialRenderState.reset();
 		TextureBinder.resetLightAndOverlay();

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/OitFramebuffer.java

@@ -13,7 +13,6 @@ import dev.engine_room.flywheel.backend.gl.GlTextureUnit;
 import net.minecraft.client.Minecraft;
 
 public class OitFramebuffer {
-
 	private final IndirectPrograms programs;
 	private final int vao;
 
@@ -27,16 +26,25 @@ public class OitFramebuffer {
 
 	public OitFramebuffer(IndirectPrograms programs) {
 		this.programs = programs;
-		fbo = GL46.glCreateFramebuffers();
 		vao = GL46.glCreateVertexArrays();
 	}
 
-	public void depthRange() {
+	/**
+	 * Set up the framebuffer.
+	 */
+	public void prepare() {
 		var mainRenderTarget = Minecraft.getInstance()
 				.getMainRenderTarget();
 
-		createTextures(mainRenderTarget.width, mainRenderTarget.height);
+		maybeResizeFBO(mainRenderTarget.width, mainRenderTarget.height);
 
+		GL46.glNamedFramebufferTexture(fbo, GL46.GL_DEPTH_ATTACHMENT, mainRenderTarget.getDepthTextureId(), 0);
+	}
+
+	/**
+	 * Render out the min and max depth per fragment.
+	 */
+	public void depthRange() {
 		// No depth writes, but we'll still use the depth test
 		RenderSystem.depthMask(false);
 		RenderSystem.colorMask(true, true, true, true);
@@ -44,8 +52,6 @@ public class OitFramebuffer {
 		RenderSystem.blendFunc(GlStateManager.SourceFactor.ONE, GlStateManager.DestFactor.ONE);
 		RenderSystem.blendEquation(GL46.GL_MAX);
 
-		GL46.glNamedFramebufferTexture(fbo, GL46.GL_DEPTH_ATTACHMENT, mainRenderTarget.getDepthTextureId(), 0);
-
 		GL46.glNamedFramebufferDrawBuffers(fbo, new int[]{GL46.GL_COLOR_ATTACHMENT0});
 
 		var far = Minecraft.getInstance().gameRenderer.getDepthFar();
@@ -55,6 +61,9 @@ public class OitFramebuffer {
 		GlStateManager._glBindFramebuffer(GL46.GL_FRAMEBUFFER, fbo);
 	}
 
+	/**
+	 * Generate the coefficients to the transmittance function.
+	 */
 	public void renderTransmittance() {
 		// No depth writes, but we'll still use the depth test
 		RenderSystem.depthMask(false);
@@ -69,11 +78,6 @@ public class OitFramebuffer {
 		Samplers.NOISE.makeActive();
 		NoiseTextures.BLUE_NOISE.bind();
 
-		NoiseTextures.BLUE_NOISE.setFilter(true, false);
-		GL46.glTextureParameteri(NoiseTextures.BLUE_NOISE.getId(), GL32.GL_TEXTURE_WRAP_S, GL32.GL_REPEAT);
-		GL46.glTextureParameteri(NoiseTextures.BLUE_NOISE.getId(), GL32.GL_TEXTURE_WRAP_T, GL32.GL_REPEAT);
-
-
 		GL46.glNamedFramebufferDrawBuffers(fbo, new int[]{GL46.GL_COLOR_ATTACHMENT1, GL46.GL_COLOR_ATTACHMENT2, GL46.GL_COLOR_ATTACHMENT3, GL46.GL_COLOR_ATTACHMENT4});
 
 		GL46.glClearNamedFramebufferfv(fbo, GL46.GL_COLOR, 0, new float[]{0, 0, 0, 0});
@@ -84,6 +88,34 @@ public class OitFramebuffer {
 		GlStateManager._glBindFramebuffer(GL46.GL_FRAMEBUFFER, fbo);
 	}
 
+	/**
+	 * If any fragment has its transmittance fall off to zero, search the transmittance
+	 * function to determine at what depth that occurs and write out to the depth buffer.
+	 */
+	public void renderDepth() {
+		// No depth writes, but we'll still use the depth test
+		RenderSystem.depthMask(true);
+		RenderSystem.colorMask(false, false, false, false);
+		RenderSystem.disableBlend();
+
+		Samplers.COEFFICIENTS.makeActive();
+		RenderSystem.bindTexture(0);
+		GL46.glBindTextureUnit(0, coefficients);
+
+		Samplers.DEPTH_RANGE.makeActive();
+		RenderSystem.bindTexture(depthBounds);
+
+		GL46.glNamedFramebufferDrawBuffers(fbo, new int[]{});
+
+		programs.getOitDepthProgram()
+				.bind();
+
+		drawFullscreenQuad();
+	}
+
+	/**
+	 * Sample the transmittance function and accumulate.
+	 */
 	public void shade() {
 		// No depth writes, but we'll still use the depth test
 		RenderSystem.depthMask(false);
@@ -109,30 +141,9 @@ public class OitFramebuffer {
 		GlStateManager._glBindFramebuffer(GL46.GL_FRAMEBUFFER, fbo);
 	}
 
-	public void renderDepth() {
-		// No depth writes, but we'll still use the depth test
-		RenderSystem.depthMask(true);
-		RenderSystem.colorMask(false, false, false, false);
-		RenderSystem.disableBlend();
-
-		Samplers.COEFFICIENTS.makeActive();
-		GlStateManager._bindTexture(0);
-		GL46.glBindTextureUnit(0, coefficients);
-
-		Samplers.DEPTH_RANGE.makeActive();
-		GlStateManager._bindTexture(depthBounds);
-
-		GL46.glNamedFramebufferDrawBuffers(fbo, new int[]{});
-
-		programs.getOitDepthProgram()
-				.bind();
-
-		// Empty VAO, the actual full screen triangle is generated in the vertex shader
-		GlStateManager._glBindVertexArray(vao);
-
-		GL46.glDrawArrays(GL46.GL_TRIANGLES, 0, 3);
-	}
-
+	/**
+	 * Composite the accumulated luminance onto the main framebuffer.
+	 */
 	public void composite() {
 		// No depth writes, but we'll still use the depth test
 		RenderSystem.depthMask(false);
@@ -147,27 +158,30 @@ public class OitFramebuffer {
 		mainRenderTarget.bindWrite(false);
 
 		GlTextureUnit.T0.makeActive();
-		GlStateManager._bindTexture(0);
+		RenderSystem.bindTexture(0);
 		GL46.glBindTextureUnit(0, coefficients);
 
 		GlTextureUnit.T1.makeActive();
-		GlStateManager._bindTexture(accumulate);
+		RenderSystem.bindTexture(accumulate);
 
 		programs.getOitCompositeProgram()
 				.bind();
 
-		// Empty VAO, the actual full screen triangle is generated in the vertex shader
-		GlStateManager._glBindVertexArray(vao);
-
-		GL46.glDrawArrays(GL46.GL_TRIANGLES, 0, 3);
+		drawFullscreenQuad();
 	}
 
 	public void delete() {
 		deleteTextures();
-		GL46.glDeleteFramebuffers(fbo);
 		GL46.glDeleteVertexArrays(vao);
 	}
 
+	private void drawFullscreenQuad() {
+		// Empty VAO, the actual full screen triangle is generated in the vertex shader
+		GlStateManager._glBindVertexArray(vao);
+
+		GL46.glDrawArrays(GL46.GL_TRIANGLES, 0, 3);
+	}
+
 	private void deleteTextures() {
 		if (depthBounds != -1) {
 			GL46.glDeleteTextures(depthBounds);
@@ -178,9 +192,19 @@ public class OitFramebuffer {
 		if (accumulate != -1) {
 			GL46.glDeleteTextures(accumulate);
 		}
+		if (fbo != -1) {
+			GL46.glDeleteFramebuffers(fbo);
+		}
+
+		// We sometimes get the same texture ID back when creating new textures,
+		// so bind zero to clear the GlStateManager
+		Samplers.COEFFICIENTS.makeActive();
+		RenderSystem.bindTexture(0);
+		Samplers.DEPTH_RANGE.makeActive();
+		RenderSystem.bindTexture(0);
 	}
 
-	private void createTextures(int width, int height) {
+	private void maybeResizeFBO(int width, int height) {
 		if (lastWidth == width && lastHeight == height) {
 			return;
 		}
@@ -190,13 +214,14 @@ public class OitFramebuffer {
 
 		deleteTextures();
 
+		fbo = GL46.glCreateFramebuffers();
+
 		depthBounds = GL46.glCreateTextures(GL46.GL_TEXTURE_2D);
 		coefficients = GL46.glCreateTextures(GL46.GL_TEXTURE_2D_ARRAY);
 		accumulate = GL46.glCreateTextures(GL46.GL_TEXTURE_2D);
 
 		GL46.glTextureStorage2D(depthBounds, 1, GL32.GL_RG32F, width, height);
 		GL46.glTextureStorage3D(coefficients, 1, GL32.GL_RGBA16F, width, height, 4);
-
 		GL46.glTextureStorage2D(accumulate, 1, GL32.GL_RGBA16F, width, height);
 
 		//		for (int tex : new int[]{zerothMoment, moments, composite}) {

common/src/backend/java/dev/engine_room/flywheel/backend/engine/uniform/FrameUniforms.java

@@ -116,6 +116,9 @@ public final class FrameUniforms extends UniformWriter {
 
 		ptr = writeInt(ptr, debugMode);
 
+		// OIT noise factor
+		ptr = writeFloat(ptr, 0.07f);
+
 		firstWrite = false;
 		BUFFER.markDirty();
 	}

common/src/backend/resources/assets/flywheel/flywheel/internal/common.frag

@@ -27,9 +27,6 @@ layout (binding = 8) uniform sampler2DArray _flw_coefficients;
 
 layout (binding = 9) uniform sampler2D _flw_blueNoise;
 
-
-uniform float _flw_blueNoiseFactor = 0.08;
-
 float tented_blue_noise(float normalizedDepth) {
 
     float tentIn = abs(normalizedDepth * 2. - 1);
@@ -53,7 +50,7 @@ float depth() {
     float delta = depthRange.x + depthRange.y;
     float depth = (linearDepth + depthRange.x) / delta;
 
-    return depth - tented_blue_noise(depth) * _flw_blueNoiseFactor;
+    return depth - tented_blue_noise(depth) * _flw_oitNoise;
 }
 
 #ifdef _FLW_DEPTH_RANGE

common/src/backend/resources/assets/flywheel/flywheel/internal/uniforms/frame.glsl

@@ -62,6 +62,8 @@ layout(std140) uniform _FlwFrameUniforms {
     uint flw_cameraInBlock;
 
     uint _flw_debugMode;
+
+    float _flw_oitNoise;
 };
 
 #define flw_renderOrigin (_flw_renderOrigin.xyz)