Code/net/minecraft/client/renderer/debug/SupportBlockRenderer.java

package net.minecraft.client.renderer.debug;

import com.google.common.collect.ImmutableList;
import com.mojang.blaze3d.vertex.PoseStack;
import java.util.Collections;
import java.util.List;
import java.util.function.DoubleSupplier;
import net.minecraft.Util;
import net.minecraft.client.Minecraft;
import net.minecraft.client.renderer.MultiBufferSource;
import net.minecraft.client.renderer.RenderType;
import net.minecraft.client.renderer.ShapeRenderer;
import net.minecraft.core.BlockPos;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.phys.shapes.CollisionContext;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public class SupportBlockRenderer implements DebugRenderer.SimpleDebugRenderer {
    private final Minecraft minecraft;
    private double lastUpdateTime = Double.MIN_VALUE;
    private List<Entity> surroundEntities = Collections.emptyList();

    public SupportBlockRenderer(Minecraft p_286424_) {
        this.minecraft = p_286424_;
    }

    @Override
    public void render(PoseStack p_286297_, MultiBufferSource p_286436_, double p_286291_, double p_286388_, double p_286330_) {
        double d0 = Util.getNanos();
        if (d0 - this.lastUpdateTime > 1.0E8) {
            this.lastUpdateTime = d0;
            Entity entity = this.minecraft.gameRenderer.getMainCamera().getEntity();
            this.surroundEntities = ImmutableList.copyOf(entity.level().getEntities(entity, entity.getBoundingBox().inflate(16.0)));
        }

        Player player = this.minecraft.player;
        if (player != null && player.mainSupportingBlockPos.isPresent()) {
            this.drawHighlights(p_286297_, p_286436_, p_286291_, p_286388_, p_286330_, player, () -> 0.0, 1.0F, 0.0F, 0.0F);
        }

        for (Entity entity1 : this.surroundEntities) {
            if (entity1 != player) {
                this.drawHighlights(p_286297_, p_286436_, p_286291_, p_286388_, p_286330_, entity1, () -> this.getBias(entity1), 0.0F, 1.0F, 0.0F);
            }
        }
    }

    private void drawHighlights(
        PoseStack p_286525_,
        MultiBufferSource p_286495_,
        double p_286696_,
        double p_286417_,
        double p_286386_,
        Entity p_286273_,
        DoubleSupplier p_286458_,
        float p_286487_,
        float p_286710_,
        float p_286793_
    ) {
        p_286273_.mainSupportingBlockPos.ifPresent(p_286428_ -> {
            double d0 = p_286458_.getAsDouble();
            BlockPos blockpos = p_286273_.getOnPos();
            this.highlightPosition(blockpos, p_286525_, p_286696_, p_286417_, p_286386_, p_286495_, 0.02 + d0, p_286487_, p_286710_, p_286793_);
            BlockPos blockpos1 = p_286273_.getOnPosLegacy();
            if (!blockpos1.equals(blockpos)) {
                this.highlightPosition(blockpos1, p_286525_, p_286696_, p_286417_, p_286386_, p_286495_, 0.04 + d0, 0.0F, 1.0F, 1.0F);
            }
        });
    }

    private double getBias(Entity p_286713_) {
        return 0.02 * (String.valueOf(p_286713_.getId() + 0.132453657).hashCode() % 1000) / 1000.0;
    }

    private void highlightPosition(
        BlockPos p_286268_,
        PoseStack p_286592_,
        double p_286463_,
        double p_286552_,
        double p_286660_,
        MultiBufferSource p_286314_,
        double p_286880_,
        float p_286918_,
        float p_286304_,
        float p_286672_
    ) {
        double d0 = p_286268_.getX() - p_286463_ - 2.0 * p_286880_;
        double d1 = p_286268_.getY() - p_286552_ - 2.0 * p_286880_;
        double d2 = p_286268_.getZ() - p_286660_ - 2.0 * p_286880_;
        double d3 = d0 + 1.0 + 4.0 * p_286880_;
        double d4 = d1 + 1.0 + 4.0 * p_286880_;
        double d5 = d2 + 1.0 + 4.0 * p_286880_;
        ShapeRenderer.renderLineBox(p_286592_, p_286314_.getBuffer(RenderType.lines()), d0, d1, d2, d3, d4, d5, p_286918_, p_286304_, p_286672_, 0.4F);
        DebugRenderer.renderVoxelShape(
            p_286592_,
            p_286314_.getBuffer(RenderType.lines()),
            this.minecraft.level.getBlockState(p_286268_).getCollisionShape(this.minecraft.level, p_286268_, CollisionContext.empty()).move(p_286268_),
            -p_286463_,
            -p_286552_,
            -p_286660_,
            p_286918_,
            p_286304_,
            p_286672_,
            1.0F,
            false
        );
    }
}