Early draft for single-pass compositing

This is a very early revision of the idea. Some (most) things don't
work currently.

common/src/main/java/net/caffeinemc/mods/sodium/client/gl/shader/ShaderConstants.java

@@ -9,6 +9,10 @@ private ShaderConstants(List<String> defines) {
         this.defines = defines;
     }
 
+    public static ShaderConstants empty() {
+        return new ShaderConstants(List.of());
+    }
+
     public List<String> getDefineStrings() {
         return this.defines;
     }

common/src/main/java/net/caffeinemc/mods/sodium/client/gl/shader/uniform/GlUniformFloat4v.java

@@ -1,5 +1,6 @@
 package net.caffeinemc.mods.sodium.client.gl.shader.uniform;
 
+import org.joml.Vector4fc;
 import org.lwjgl.opengl.GL30C;
 
 public class GlUniformFloat4v extends GlUniform<float[]> {
@@ -15,4 +16,12 @@ public void set(float[] value) {
 
         GL30C.glUniform4fv(this.index, value);
     }
+
+    public void set(float x, float y, float z, float w) {
+        GL30C.glUniform4f(this.index, x, y, z, w);
+    }
+
+    public void set(Vector4fc vec) {
+        this.set(vec.x(), vec.y(), vec.z(), vec.w());
+    }
 }

common/src/main/java/net/caffeinemc/mods/sodium/client/gui/SodiumGameOptionPages.java

@@ -293,6 +293,14 @@ public static OptionPage performance() {
                         .setBinding((opts, value) -> opts.performance.useEntityCulling = value, opts -> opts.performance.useEntityCulling)
                         .build()
                 )
+                .add(OptionImpl.createBuilder(boolean.class, sodiumOpts)
+                        .setName(Component.translatable("sodium.options.use_single_pass_compositing.name"))
+                        .setTooltip(Component.translatable("sodium.options.use_single_pass_compositing.tooltip"))
+                        .setControl(TickBoxControl::new)
+                        .setImpact(OptionImpact.HIGH)
+                        .setBinding((opts, value) -> opts.performance.useSinglePassCompositing = value, opts -> opts.performance.useSinglePassCompositing)
+                        .build()
+                )
                 .add(OptionImpl.createBuilder(boolean.class, sodiumOpts)
                         .setName(Component.translatable("sodium.options.animate_only_visible_textures.name"))
                         .setTooltip(Component.translatable("sodium.options.animate_only_visible_textures.tooltip"))

common/src/main/java/net/caffeinemc/mods/sodium/client/gui/SodiumGameOptions.java

@@ -45,6 +45,7 @@ public static class PerformanceSettings {
         public boolean useFogOcclusion = true;
         public boolean useBlockFaceCulling = true;
         public boolean useNoErrorGLContext = true;
+        public boolean useSinglePassCompositing = true;
 
         @SerializedName("sorting_enabled_v2") // reset the older option in configs before we started hiding it
         public boolean sortingEnabled = true;

common/src/main/java/net/caffeinemc/mods/sodium/client/render/CompositePass.java

@@ -0,0 +1,172 @@
+package net.caffeinemc.mods.sodium.client.render;
+
+import com.mojang.blaze3d.pipeline.RenderTarget;
+import com.mojang.blaze3d.platform.GlStateManager;
+import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.vertex.VertexBuffer;
+import net.caffeinemc.mods.sodium.client.gl.shader.GlProgram;
+import net.caffeinemc.mods.sodium.client.gl.shader.ShaderConstants;
+import net.caffeinemc.mods.sodium.client.gl.shader.ShaderLoader;
+import net.caffeinemc.mods.sodium.client.gl.shader.ShaderType;
+import net.caffeinemc.mods.sodium.client.gl.shader.uniform.GlUniformFloat4v;
+import net.caffeinemc.mods.sodium.client.gl.shader.uniform.GlUniformInt;
+import net.caffeinemc.mods.sodium.client.render.chunk.shader.ShaderBindingContext;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.texture.AbstractTexture;
+import net.minecraft.client.renderer.texture.TextureManager;
+import net.minecraft.resources.ResourceLocation;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.joml.Vector4f;
+import org.lwjgl.opengl.GL33C;
+import org.lwjgl.opengl.GL45C;
+
+import java.util.EnumSet;
+
+public class CompositePass {
+    public static boolean ENABLED;
+
+    public static boolean ENTITY_GLOW_IS_ACTIVE = false;
+
+    private static final Vector4f VIGNETTE_COLOR = new Vector4f();
+
+    private static int DEFAULT_VERTEX_ARRAY;
+    private static GlProgram<CompositeProgramInterface> COMPOSITE_PROGRAM;
+
+    public static void composite(@NotNull RenderTarget mainRT,
+                                 @Nullable RenderTarget entityRT,
+                                 int width,
+                                 int height) {
+        EnumSet<BlendOption> blendOptions = EnumSet.noneOf(BlendOption.class);
+
+        if (entityRT != null && isEntityGlowIsActive()) {
+            blendOptions.add(BlendOption.USE_ENTITY_GLOW);
+        }
+
+        if (isVignetteActive()) {
+            blendOptions.add(BlendOption.USE_VIGNETTE);
+        }
+
+        if (blendOptions.isEmpty()) {
+            // If no compositing is necessary, we can just blit the main render target to
+            // the default framebuffer and avoid using the rasterization pipeline.
+            mainRT.blitToScreen(width, height, true);
+            return;
+        }
+
+        if (COMPOSITE_PROGRAM == null) {
+            COMPOSITE_PROGRAM = GlProgram.builder(ResourceLocation.fromNamespaceAndPath("sodium", "composite"))
+                    .attachShader(ShaderLoader.loadShader(ShaderType.VERTEX, ResourceLocation.fromNamespaceAndPath("sodium", "composite.vsh"), ShaderConstants.empty()))
+                    .attachShader(ShaderLoader.loadShader(ShaderType.FRAGMENT, ResourceLocation.fromNamespaceAndPath("sodium", "composite.fsh"), ShaderConstants.empty()))
+                    .bindFragmentData("fragColor", 0)
+                    .link(CompositeProgramInterface::new);
+
+            DEFAULT_VERTEX_ARRAY = GL33C.glGenVertexArrays();
+        }
+
+        VertexBuffer.unbind();
+
+        GlStateManager._disableDepthTest();
+        GlStateManager._disableBlend();
+
+        GlStateManager._colorMask(true, true, true, false);
+        GlStateManager._depthMask(false);
+
+        GlStateManager._glUseProgram(COMPOSITE_PROGRAM.handle());
+        GlStateManager._glBindVertexArray(DEFAULT_VERTEX_ARRAY);
+
+        var uniforms = COMPOSITE_PROGRAM.getInterface();
+        uniforms.mainColorRT.set(0);
+        uniforms.entityColorRT.set(1);
+        uniforms.vignetteTexture.set(2);
+        uniforms.vignetteColorModulator.set(VIGNETTE_COLOR);
+        uniforms.blendOptions.set(toBitfield(blendOptions));
+
+        bindTextureToUnit(0, mainRT.getColorTextureId());
+
+        if (entityRT != null) {
+            bindTextureToUnit(1, blendOptions.contains(BlendOption.USE_ENTITY_GLOW) ? entityRT.getColorTextureId() : 0 /* default texture */);
+        }
+
+        bindTextureToUnit(2, getVignetteTextureId());
+
+        GL45C.glDrawArrays(GL45C.GL_TRIANGLES, 0, 3);
+
+        unbindTextureFromUnit(0);
+        unbindTextureFromUnit(1);
+        unbindTextureFromUnit(2);
+
+        GlStateManager._depthMask(true);
+        GlStateManager._colorMask(true, true, true, true);
+
+        GlStateManager._enableBlend();
+        GlStateManager._enableDepthTest();
+
+        CompositePass.ENTITY_GLOW_IS_ACTIVE = false;
+    }
+
+    private static boolean isEntityGlowIsActive() {
+        return CompositePass.ENTITY_GLOW_IS_ACTIVE;
+    }
+
+    private static boolean isVignetteActive() {
+        return VIGNETTE_COLOR.w() >= 0.0025f;
+    }
+
+    private static int toBitfield(EnumSet<?> set) {
+        int bits = 0;
+
+        for (var value : set) {
+            bits = (1 << value.ordinal());
+        }
+
+        return bits;
+    }
+
+    private static void unbindTextureFromUnit(int slot) {
+        RenderSystem.activeTexture(GL33C.GL_TEXTURE0 + slot);
+        RenderSystem.bindTexture(0);
+    }
+
+    private static void bindTextureToUnit(int slot, int texture) {
+        RenderSystem.activeTexture(GL33C.GL_TEXTURE0 + slot);
+        RenderSystem.bindTexture(texture);
+    }
+
+    public static void setVignetteColor(float[] color) {
+        VIGNETTE_COLOR.set(color);
+    }
+
+    private static class CompositeProgramInterface {
+        private final GlUniformInt mainColorRT;
+        private final GlUniformInt entityColorRT;
+
+        private final GlUniformInt vignetteTexture;
+        private final GlUniformFloat4v vignetteColorModulator;
+
+        private final GlUniformInt blendOptions;
+
+        public CompositeProgramInterface(ShaderBindingContext ctx) {
+            this.mainColorRT = ctx.bindUniform("mainColorRT", GlUniformInt::new);
+            this.entityColorRT = ctx.bindUniform("entityColorRT", GlUniformInt::new);
+
+            this.vignetteTexture = ctx.bindUniform("vignetteTexture", GlUniformInt::new);
+            this.vignetteColorModulator = ctx.bindUniform("vignetteColorModulator", GlUniformFloat4v::new);
+
+            this.blendOptions = ctx.bindUniform("blendOptions", GlUniformInt::new);
+        }
+    }
+
+    private static int getVignetteTextureId() {
+        Minecraft minecraft = Minecraft.getInstance();
+        TextureManager textureManager = minecraft.getTextureManager();
+        AbstractTexture texture = textureManager.getTexture(ResourceLocation.parse("textures/misc/vignette.png"));
+
+        return texture.getId();
+    }
+
+    private enum BlendOption {
+        USE_ENTITY_GLOW,
+        USE_VIGNETTE
+    }
+}

common/src/main/java/net/caffeinemc/mods/sodium/mixin/features/render/compositing/GameRendererMixin.java

@@ -0,0 +1,37 @@
+package net.caffeinemc.mods.sodium.mixin.features.render.compositing;
+
+import com.mojang.blaze3d.pipeline.RenderTarget;
+import com.mojang.blaze3d.platform.Window;
+import net.caffeinemc.mods.sodium.client.render.CompositePass;
+import net.minecraft.client.DeltaTracker;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.GameRenderer;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(GameRenderer.class)
+public class GameRendererMixin {
+    @Inject(method = "render", at = @At(value = "INVOKE", target = "Lcom/mojang/blaze3d/systems/RenderSystem;clear(IZ)V", ordinal = 0, shift = At.Shift.BEFORE))
+    private void preRenderGui(DeltaTracker deltaTracker, boolean renderLevel, CallbackInfo ci) {
+        if (!CompositePass.ENABLED) {
+            return;
+        }
+
+        Minecraft minecraft = Minecraft.getInstance();
+        Window window = minecraft.getWindow();
+
+        int width = window.getWidth();
+        int height = window.getHeight();
+
+        RenderTarget mainRT = minecraft.getMainRenderTarget();
+        mainRT.unbindWrite();
+
+        if (minecraft.level != null) {
+            CompositePass.composite(mainRT, minecraft.levelRenderer.entityTarget(), width, height);
+        } else {
+            mainRT.blitToScreen(width, height, true);
+        }
+    }
+}

common/src/main/java/net/caffeinemc/mods/sodium/mixin/features/render/compositing/GuiMixin.java

@@ -0,0 +1,26 @@
+package net.caffeinemc.mods.sodium.mixin.features.render.compositing;
+
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import com.mojang.blaze3d.systems.RenderSystem;
+import net.caffeinemc.mods.sodium.client.render.CompositePass;
+import net.minecraft.client.gui.Gui;
+import net.minecraft.client.gui.GuiGraphics;
+import net.minecraft.resources.ResourceLocation;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+@Mixin(Gui.class)
+public class GuiMixin {
+    // We can't separately query the vignette color, so we instead hook the render function
+    // and look at the render state to figure out what color is used.
+    @WrapOperation(method = "renderVignette", at = @At(value = "INVOKE", target = "Lnet/minecraft/client/gui/GuiGraphics;blit(Lnet/minecraft/resources/ResourceLocation;IIIFFIIII)V"))
+    public void beforeBlit(GuiGraphics gui, ResourceLocation texture, int x, int y, int z, float u1, float v1, int u2, int v2, int textureWidth, int textureHeight, Operation<Void> original) {
+        if (CompositePass.ENABLED) {
+            // The blit will happen later in the final compositing pass
+            CompositePass.setVignetteColor(RenderSystem.getShaderColor());
+        } else {
+            original.call(gui, texture, x, y, z, u1, v1, u2, v2, textureWidth, textureHeight);
+        }
+    }
+}

common/src/main/java/net/caffeinemc/mods/sodium/mixin/features/render/compositing/LevelRendererMixin.java

@@ -0,0 +1,34 @@
+package net.caffeinemc.mods.sodium.mixin.features.render.compositing;
+
+import com.mojang.blaze3d.vertex.PoseStack;
+import net.caffeinemc.mods.sodium.client.render.CompositePass;
+import net.minecraft.client.renderer.LevelRenderer;
+import net.minecraft.client.renderer.MultiBufferSource;
+import net.minecraft.client.renderer.OutlineBufferSource;
+import net.minecraft.world.entity.Entity;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(LevelRenderer.class)
+public class LevelRendererMixin {
+    @Inject(method = "doEntityOutline", at = @At("HEAD"), cancellable = true)
+    public void cancelEntityOutlineComposite(CallbackInfo ci) {
+        // Normally, the entity outline buffer would be blurred and then composited into the
+        // main render target, but we want to defer this until our final compositing pass.
+        if (CompositePass.ENABLED) {
+            ci.cancel();
+        }
+    }
+
+    @Inject(method = "renderEntity", at = @At("HEAD"))
+    private void onEntityRendered(Entity entity, double d, double e, double f, float g, PoseStack poseStack, MultiBufferSource multiBufferSource, CallbackInfo ci) {
+        // If any entities are rendered with an outline effect, mark the entity glow render target
+        // as needing to be composited into the final image. Otherwise, we can skip compositing when
+        // there are no glowing entities.
+        if (multiBufferSource instanceof OutlineBufferSource) {
+            CompositePass.ENTITY_GLOW_IS_ACTIVE = true;
+        }
+    }
+}