Add portal rendering (wip)

src/main/java/com/minelittlepony/unicopia/client/render/RenderUtil.java

@@ -17,18 +17,27 @@ public class RenderUtil {
             new Vertex(new Vector3f(1, 1, 0), 0, 0),
             new Vertex(new Vector3f(1, 0, 0), 0, 1)
     };
+    public static final Vertex[] FRAME_BUFFER_VERTICES = new Vertex[] {
+            new Vertex(new Vector3f(0, 1, 0), 0, 0),
+            new Vertex(new Vector3f(1, 1, 0), 1, 0),
+            new Vertex(new Vector3f(1, 0, 0), 1, 1),
+            new Vertex(new Vector3f(0, 0, 0), 0, 1)
+    };
 
     public static void renderFace(MatrixStack matrices, Tessellator te, BufferBuilder buffer, float r, float g, float b, float a, int light) {
+        renderFace(matrices, te, buffer, r, g, b, a, light, 1, 1);
+    }
+
+    public static void renderFace(MatrixStack matrices, Tessellator te, BufferBuilder buffer, float r, float g, float b, float a, int light, float uScale, float vScale) {
         buffer.begin(VertexFormat.DrawMode.QUADS, VertexFormats.POSITION_TEXTURE_COLOR_LIGHT);
         for (Vertex vertex : UNIT_FACE) {
             Vector4f position = vertex.position(matrices);
-            buffer.vertex(position.x, position.y, position.z).texture(vertex.u(), vertex.v()).color(r, g, b, a).light(light).next();
+            buffer.vertex(position.x, position.y, position.z).texture(vertex.u() * uScale, vertex.v() * vScale).color(r, g, b, a).light(light).next();
         }
         te.draw();
     }
 
     public record Vertex(Vector3f position, float u, float v) {
-
         public Vector4f position(MatrixStack matrices) {
             matrices.peek().getPositionMatrix().transform(TEMP_VECTOR.set(position, 1));
             return TEMP_VECTOR;

src/main/java/com/minelittlepony/unicopia/client/render/model/SphereModel.java

@@ -20,7 +20,7 @@ public class SphereModel extends BakedModel {
         compileVertices(azimuthRange, zenithIncrement, azimuthIncrement, this::addVertex);
     }
 
-    private static void compileVertices(double azimuthRange, double zenithIncrement, double azimuthIncrement, Consumer<Vector4f> collector) {
+    static void compileVertices(double azimuthRange, double zenithIncrement, double azimuthIncrement, Consumer<Vector4f> collector) {
         Vector4f vector = new Vector4f();
         for (double zenith = 0; zenith < DrawableUtil.PI; zenith += zenithIncrement) {
             for (double azimuth = 0; azimuth < azimuthRange; azimuth += azimuthIncrement) {

src/main/java/com/minelittlepony/unicopia/client/render/model/TexturedSphereModel.java

@@ -0,0 +1,41 @@
+package com.minelittlepony.unicopia.client.render.model;
+
+import org.joml.Vector4f;
+
+import com.minelittlepony.unicopia.client.gui.DrawableUtil;
+import com.minelittlepony.unicopia.client.render.RenderUtil;
+
+import net.minecraft.client.render.VertexConsumer;
+import net.minecraft.client.util.math.MatrixStack;
+
+public class TexturedSphereModel extends BakedModel {
+    public static final TexturedSphereModel DISK = new TexturedSphereModel(40, 2, DrawableUtil.PI);
+
+    public TexturedSphereModel(double rings, double sectors, double azimuthRange) {
+        double zenithIncrement = DrawableUtil.PI / rings;
+        double azimuthIncrement = DrawableUtil.TAU / sectors;
+        SphereModel.compileVertices(azimuthRange, zenithIncrement, azimuthIncrement, this::addVertex);
+    }
+
+    @Override
+    protected void addVertex(Vector4f vertex) {
+        addVertex(vertex.x, vertex.y, vertex.z, vertex.x, vertex.z);
+    }
+
+    public final void render(MatrixStack matrices, VertexConsumer buffer, float scale, float r, float g, float b, float a, float uScale, float vScale) {
+        scale = Math.abs(scale);
+        if (scale < 0.001F) {
+            return;
+        }
+
+        matrices.push();
+        matrices.scale(scale, scale, scale);
+        uScale *= 0.5F;
+        vScale *= 0.5F;
+        for (RenderUtil.Vertex vertex : vertices) {
+            Vector4f pos = vertex.position(matrices);
+            buffer.vertex(pos.x, pos.y, pos.z).texture((vertex.u() + 1) * uScale, (vertex.v() + 1) * vScale).color(r, g, b, a).next();
+        }
+        matrices.pop();
+    }
+}

src/main/java/com/minelittlepony/unicopia/client/render/spell/PlacedSpellRenderer.java

@@ -27,6 +27,8 @@ public class PlacedSpellRenderer extends SpellRenderer<PlaceableSpell> {
 
     @Override
     public void render(MatrixStack matrices, VertexConsumerProvider vertices, PlaceableSpell spell, Caster<?> caster, int light, float limbAngle, float limbDistance, float tickDelta, float animationProgress, float headYaw, float headPitch) {
+
+
         if (!(caster.asEntity() instanceof CastSpellEntity castSpell)) {
             return;
         }

src/main/java/com/minelittlepony/unicopia/client/render/spell/PortalSpellRenderer.java

@@ -1,17 +1,57 @@
 package com.minelittlepony.unicopia.client.render.spell;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import org.jetbrains.annotations.Nullable;
+import org.joml.Matrix3f;
+import org.joml.Matrix4f;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
 import com.minelittlepony.common.util.Color;
 import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.PortalSpell;
 import com.minelittlepony.unicopia.client.render.RenderLayers;
 import com.minelittlepony.unicopia.client.render.model.SphereModel;
+import com.minelittlepony.unicopia.client.render.model.TexturedSphereModel;
+import com.minelittlepony.unicopia.entity.EntityReference;
+import com.minelittlepony.unicopia.entity.mob.UEntities;
+import com.minelittlepony.unicopia.mixin.client.MixinMinecraftClient;
+import com.mojang.blaze3d.platform.GlConst;
+import com.mojang.blaze3d.systems.RenderSystem;
+import com.mojang.blaze3d.systems.VertexSorter;
 
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.gl.SimpleFramebuffer;
+import net.minecraft.client.option.Perspective;
+import net.minecraft.client.render.BackgroundRenderer;
+import net.minecraft.client.render.BufferBuilder;
+import net.minecraft.client.render.Camera;
+import net.minecraft.client.render.GameRenderer;
+import net.minecraft.client.render.Tessellator;
 import net.minecraft.client.render.VertexConsumer;
 import net.minecraft.client.render.VertexConsumerProvider;
+import net.minecraft.client.render.VertexFormat;
+import net.minecraft.client.render.VertexFormats;
+import net.minecraft.client.util.Window;
 import net.minecraft.client.util.math.MatrixStack;
+import net.minecraft.entity.Entity;
+import net.minecraft.screen.PlayerScreenHandler;
+import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.RotationAxis;
+import net.minecraft.util.math.Vec3d;
 
 public class PortalSpellRenderer extends SpellRenderer<PortalSpell> {
+    private static final LoadingCache<UUID, PortalFrameBuffer> FRAME_BUFFERS = CacheBuilder.newBuilder()
+            .expireAfterAccess(10, TimeUnit.SECONDS)
+            .<UUID, PortalFrameBuffer>removalListener(n -> n.getValue().close())
+            .build(CacheLoader.from(uuid -> new PortalFrameBuffer()));
 
     @Override
     public boolean shouldRenderEffectPass(int pass) {
@@ -32,20 +72,228 @@ public class PortalSpellRenderer extends SpellRenderer<PortalSpell> {
         float green = Color.g(color);
         float blue = Color.b(color);
 
-        VertexConsumer buffer = vertices.getBuffer(RenderLayers.getEndGateway());
+        VertexConsumer buff = vertices.getBuffer(RenderLayers.getEndGateway());
-
-        double thickness = 0.1;
 
         matrices.push();
-        matrices.translate(0, thickness, 0);
+        matrices.translate(0, 0.02, 0);
-        SphereModel.DISK.render(matrices, buffer, light, 0, 2.5F, red, green, blue, 1);
+        SphereModel.DISK.render(matrices, buff, light, 0, 2F, red, green, blue, 1);
         matrices.pop();
 
+        if (caster.asEntity().distanceTo(client.cameraEntity) > 50) {
+            return; // don't bother rendering if too far away
+        }
+
+        spell.getTarget().ifPresent(target -> {
+            try {
+                float grown = Math.min(caster.asEntity().age, 20) / 20F;
                 matrices.push();
-        matrices.multiply(RotationAxis.POSITIVE_X.rotationDegrees(180));
+                matrices.translate(0, 0.01, 0);
-        matrices.translate(0, thickness, 0);
+                matrices.multiply(RotationAxis.POSITIVE_Y.rotationDegrees(-spell.getYaw()));
-        SphereModel.DISK.render(matrices, buffer, light, 0, 2.5F, red, green, blue, 1);
+                matrices.scale(grown, 1, grown);
-
+                PortalFrameBuffer buffer = FRAME_BUFFERS.get(target.uuid());
+                buffer.build(spell, caster, target);
+                buffer.draw(matrices);
                 matrices.pop();
+            } catch (ExecutionException e) { }
+        });
+    }
+
+    static class PortalFrameBuffer implements AutoCloseable {
+        @Nullable
+        private SimpleFramebuffer framebuffer;
+        private boolean closed;
+
+        private final MinecraftClient client = MinecraftClient.getInstance();
+
+        private boolean pendingDraw;
+
+        private static int recursionCount;
+
+        public void draw(MatrixStack matrices) {
+            if (closed || framebuffer == null) {
+                return;
+            }
+            float uScale = (float)framebuffer.viewportWidth / (float)framebuffer.textureWidth;
+            float vScale = (float)framebuffer.viewportHeight / (float)framebuffer.textureHeight;
+
+            Tessellator tessellator = RenderSystem.renderThreadTesselator();
+            BufferBuilder buffer = tessellator.getBuffer();
+
+            RenderSystem.enableDepthTest();
+            RenderSystem.disableCull();
+            RenderSystem.setShaderTexture(0, framebuffer.getColorAttachment());
+            RenderSystem.setShader(GameRenderer::getPositionTexColorProgram);
+
+            Matrix4f textureMatrix = matrices.peek().getPositionMatrix();
+
+            RenderSystem.setTextureMatrix(textureMatrix);
+
+            buffer.begin(VertexFormat.DrawMode.QUADS, VertexFormats.POSITION_TEXTURE_COLOR);
+            TexturedSphereModel.DISK.render(matrices, buffer, 2F, 1, 1, 1, 1, uScale, vScale);
+            tessellator.draw();
+            client.getTextureManager().bindTexture(PlayerScreenHandler.BLOCK_ATLAS_TEXTURE);
+            RenderSystem.enableCull();
+            RenderSystem.resetTextureMatrix();
+        }
+
+        public void build(PortalSpell spell, Caster<?> caster, EntityReference.EntityValues<Entity> target) {
+
+            if (System.currentTimeMillis() % 100 < 50) {
+                return;
+            }
+
+            if (pendingDraw && recursionCount > 0) {
+                innerBuild(spell, caster, target);
+                return;
+            }
+
+            if (pendingDraw) {
+                return;
+            }
+            pendingDraw = true;
+            if (recursionCount > 0) {
+                innerBuild(spell, caster, target);
+            } else {
+                ((MixinMinecraftClient)client).getRenderTaskQueue().add(() -> innerBuild(spell, caster, target));
+            }
+        }
+
+        private void innerBuild(PortalSpell spell, Caster<?> caster, EntityReference.EntityValues<Entity> target) {
+            synchronized (client) {
+                pendingDraw = false;
+
+                if (recursionCount > 2) {
+                    return;
+                }
+                recursionCount++;
+
+                try {
+                    if (closed || client.interactionManager == null) {
+                        close();
+                        return;
+                    }
+
+                    var fov = client.options.getFov();
+                    int originalFov = fov.getValue();
+                    fov.setValue(110);
+
+                    Vec3d offset = new Vec3d(0, -1.2, -0.2);
+                    float yaw = spell.getYawDifference();// spell.getYawDifference();
+
+                    offset = offset.rotateY(yaw * MathHelper.RADIANS_PER_DEGREE);
+
+                    Entity cameraEntity = UEntities.CAST_SPELL.create(caster.asWorld());
+                    cameraEntity.setPosition(target.pos().add(offset));
+                    cameraEntity.setPitch(spell.getTargetPitch());
+                    cameraEntity.setYaw(yaw);
+
+                    drawWorld(cameraEntity, 400, 400);
+
+                    fov.setValue(originalFov);
+                } finally {
+                    recursionCount--;
+                }
+            }
+        }
+
+        @SuppressWarnings({ "rawtypes", "unchecked" })
+        private void drawWorld(Entity cameraEntity, int width, int height) {
+            Entity oldCameraEntity = client.cameraEntity;
+            client.cameraEntity = cameraEntity;
+
+            Window window = client.getWindow();
+
+            Perspective perspective = client.options.getPerspective();
+            client.options.setPerspective(Perspective.FIRST_PERSON);
+
+            int i = window.getFramebufferWidth();
+            int j = window.getFramebufferHeight();
+
+            width = i;
+            height = j;
+
+            client.getFramebuffer().endWrite();
+
+            if (framebuffer == null) {
+                framebuffer = new SimpleFramebuffer(width, height, true, MinecraftClient.IS_SYSTEM_MAC);
+            }
+
+            window.setFramebufferWidth(width);
+            window.setFramebufferHeight(height);
+
+            MatrixStack view = RenderSystem.getModelViewStack();
+            view.push();
+            view.loadIdentity();
+            RenderSystem.applyModelViewMatrix();
+            Matrix4f proj = RenderSystem.getProjectionMatrix();
+            Matrix3f invView = RenderSystem.getInverseViewRotationMatrix();
+
+            int fbo = client.getFramebuffer().fbo;
+            client.getFramebuffer().fbo = framebuffer.fbo;
+
+            framebuffer.setClearColor(0, 0, 0, 0);
+            framebuffer.clear(MinecraftClient.IS_SYSTEM_MAC);
+
+            RenderSystem.clear(GlConst.GL_DEPTH_BUFFER_BIT | GlConst.GL_COLOR_BUFFER_BIT, MinecraftClient.IS_SYSTEM_MAC);
+            framebuffer.beginWrite(true);
+            BackgroundRenderer.clearFog();
+
+            Camera camera = client.gameRenderer.getCamera();
+
+            ObjectArrayList<?> chunkInfos = ((WorldRendererDuck)client.worldRenderer).unicopia_getChunkInfos();
+            List<Object> backup = new ArrayList<>(chunkInfos);
+
+            client.gameRenderer.setRenderHand(false);
+            MatrixStack matrices = new MatrixStack();
+
+            matrices.scale((float)width / height, 1, 1);
+
+            client.gameRenderer.renderWorld(1, 0, matrices);
+            if (recursionCount <= 1) {
+                client.gameRenderer.setRenderHand(true);
+            }
+            framebuffer.endWrite();
+
+            chunkInfos.clear();
+            chunkInfos.addAll((List)backup);
+
+            view.pop();
+            RenderSystem.applyModelViewMatrix();
+
+            client.getFramebuffer().fbo = fbo;
+            window.setFramebufferWidth(i);
+            window.setFramebufferHeight(j);
+
+            client.options.setPerspective(perspective);
+            client.cameraEntity = oldCameraEntity;
+
+            RenderSystem.setProjectionMatrix(proj, VertexSorter.BY_Z);
+            RenderSystem.setInverseViewRotationMatrix(invView);
+
+            if (recursionCount <= 1) {
+                camera.update(client.world,
+                        client.getCameraEntity() == null ? client.player : client.getCameraEntity(),
+                        perspective.isFirstPerson(),
+                        perspective.isFrontView(),
+                        1
+                );
+            }
+
+            client.getFramebuffer().beginWrite(true);
+        }
+
+        @Override
+        public void close() {
+            closed = true;
+            if (framebuffer != null) {
+                SimpleFramebuffer fb = framebuffer;
+                framebuffer = null;
+                fb.delete();
+            }
+        }
+    }
+
+    public interface WorldRendererDuck {
+        ObjectArrayList<?> unicopia_getChunkInfos();
     }
 }

src/main/java/com/minelittlepony/unicopia/mixin/client/MixinMinecraftClient.java

@@ -0,0 +1,14 @@
+package com.minelittlepony.unicopia.mixin.client;
+
+import java.util.Queue;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+import net.minecraft.client.MinecraftClient;
+
+@Mixin(MinecraftClient.class)
+public interface MixinMinecraftClient {
+    @Accessor("renderTaskQueue")
+    Queue<Runnable> getRenderTaskQueue();
+}

src/main/java/com/minelittlepony/unicopia/mixin/client/MixinWorldRenderer.java

@@ -15,7 +15,10 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 import com.minelittlepony.unicopia.client.ClientBlockDestructionManager;
 import com.minelittlepony.unicopia.client.UnicopiaClient;
+import com.minelittlepony.unicopia.client.render.spell.PortalSpellRenderer;
+
 import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 import net.minecraft.client.render.BlockBreakingInfo;
 import net.minecraft.client.render.Camera;
 import net.minecraft.client.render.WorldRenderer;
@@ -25,7 +28,7 @@ import net.minecraft.resource.SynchronousResourceReloader;
 import net.minecraft.util.math.RotationAxis;
 
 @Mixin(value = WorldRenderer.class, priority = 1001)
-abstract class MixinWorldRenderer implements SynchronousResourceReloader, AutoCloseable, ClientBlockDestructionManager.Source {
+abstract class MixinWorldRenderer implements SynchronousResourceReloader, AutoCloseable, ClientBlockDestructionManager.Source, PortalSpellRenderer.WorldRendererDuck {
 
     private final ClientBlockDestructionManager destructions = new ClientBlockDestructionManager();
 
@@ -41,6 +44,10 @@ abstract class MixinWorldRenderer implements SynchronousResourceReloader, AutoCl
         return destructions;
     }
 
+    @Override
+    @Accessor("chunkInfos")
+    public abstract ObjectArrayList<?> unicopia_getChunkInfos();
+
     @Override
     @Accessor("ticks")
     public abstract int getTicks();

src/main/resources/unicopia.mixin.json

@@ -73,6 +73,7 @@
     "client.MixinItemStack",
     "client.MixinKeyboardInput",
     "client.MixinLivingEntityRenderer",
+    "client.MixinMinecraftClient",
     "client.MixinModelPart",
     "client.MixinMouse",
     "client.MixinPlayerEntityRenderer",