NaturesAura/src/main/java/de/ellpeck/naturesaura/particles/ParticleMagic.java

package de.ellpeck.naturesaura.particles;

import com.mojang.blaze3d.vertex.VertexConsumer;
import com.mojang.math.Quaternion;
import com.mojang.math.Vector3f;
import de.ellpeck.naturesaura.NaturesAura;
import net.minecraft.client.Camera;
import net.minecraft.client.multiplayer.ClientLevel;
import net.minecraft.client.particle.Particle;
import net.minecraft.client.particle.ParticleRenderType;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.Mth;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.phys.Vec3;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

import java.util.Collections;

@OnlyIn(Dist.CLIENT)
public class ParticleMagic extends Particle {

    public static final ResourceLocation TEXTURE = new ResourceLocation(NaturesAura.MOD_ID, "textures/particles/magic_round.png");

    private final float desiredScale;
    private final boolean fade;
    private final boolean depth;
    private float particleScale;

    public ParticleMagic(ClientLevel level, double posX, double posY, double posZ, double motionX, double motionY, double motionZ, int color, float scale, int maxAge, float gravity, boolean collision, boolean fade, boolean depth) {
        super(level, posX, posY, posZ);
        this.desiredScale = scale;
        this.lifetime = maxAge;
        this.hasPhysics = collision;
        this.gravity = gravity;
        this.fade = fade;
        this.depth = depth;

        this.xd = motionX;
        this.yd = motionY;
        this.zd = motionZ;

        var r = (color >> 16 & 255) / 255F * (1F - this.random.nextFloat() * 0.25F);
        var g = (color >> 8 & 255) / 255F * (1F - this.random.nextFloat() * 0.25F);
        var b = (color & 255) / 255F * (1F - this.random.nextFloat() * 0.25F);
        this.setColor(r, g, b);

        this.alpha = 1F;
        this.particleScale = 0F;
    }

    @Override
    public void tick() {
        this.xo = this.x;
        this.yo = this.y;
        this.zo = this.z;

        this.age++;
        if (this.age > this.lifetime) {
            this.remove();
        } else {
            this.yd -= 0.04D * (double) this.gravity;
            this.move(this.xd, this.yd, this.zd);

            var lifeRatio = (float) this.age / (float) this.lifetime;
            if (this.fade && lifeRatio > 0.75F)
                this.alpha = 1F - (lifeRatio - 0.75F) / 0.25F;
            if (lifeRatio <= 0.25F)
                this.particleScale = this.desiredScale * (lifeRatio / 0.25F);
            else if (this.fade)
                this.particleScale = this.desiredScale * (1F - (lifeRatio - 0.25F) / 0.75F);
        }
    }

    @Override
    public void move(double x, double y, double z) {
        var lastY = y;
        if (this.hasPhysics && (x != 0 || y != 0 || z != 0)) {
            var motion = Entity.collideBoundingBox(null, new Vec3(x, y, z), this.getBoundingBox(), this.level, Collections.emptyList());
            x = motion.x;
            y = motion.y;
            z = motion.z;
        }
        if (x != 0 || y != 0 || z != 0) {
            this.setBoundingBox(this.getBoundingBox().move(x, y, z));
            this.setLocationFromBoundingbox();
        }
        this.onGround = lastY != y && lastY < 0;
        if (this.onGround) {
            this.xd = 0;
            this.zd = 0;
        }
    }

    @Override
    public void render(VertexConsumer buffer, Camera renderInfo, float partialTicks) {
        var vec3d = renderInfo.getPosition();
        var f = (float) (Mth.lerp(partialTicks, this.xo, this.x) - vec3d.x);
        var f1 = (float) (Mth.lerp(partialTicks, this.yo, this.y) - vec3d.y);
        var f2 = (float) (Mth.lerp(partialTicks, this.zo, this.z) - vec3d.z);
        var quaternion = renderInfo.rotation();
        var avector3f = new Vector3f[]{new Vector3f(-1.0F, -1.0F, 0.0F), new Vector3f(-1.0F, 1.0F, 0.0F), new Vector3f(1.0F, 1.0F, 0.0F), new Vector3f(1.0F, -1.0F, 0.0F)};
        var f4 = 0.1F * this.particleScale;

        for (var i = 0; i < 4; ++i) {
            var vector3f = avector3f[i];
            vector3f.transform(quaternion);
            vector3f.mul(f4);
            vector3f.add(f, f1, f2);
        }

        var j = this.getLightColor(partialTicks);
        buffer.vertex(avector3f[0].x(), avector3f[0].y(), avector3f[0].z()).uv(0, 1).color(this.rCol, this.gCol, this.bCol, this.alpha).uv2(j).endVertex();
        buffer.vertex(avector3f[1].x(), avector3f[1].y(), avector3f[1].z()).uv(1, 1).color(this.rCol, this.gCol, this.bCol, this.alpha).uv2(j).endVertex();
        buffer.vertex(avector3f[2].x(), avector3f[2].y(), avector3f[2].z()).uv(1, 0).color(this.rCol, this.gCol, this.bCol, this.alpha).uv2(j).endVertex();
        buffer.vertex(avector3f[3].x(), avector3f[3].y(), avector3f[3].z()).uv(0, 0).color(this.rCol, this.gCol, this.bCol, this.alpha).uv2(j).endVertex();
    }

    @Override
    public ParticleRenderType getRenderType() {
        return this.depth ? ParticleHandler.MAGIC : ParticleHandler.MAGIC_NO_DEPTH;
    }

    @Override
    protected int getLightColor(float p_107249_) {
        return 15 << 20 | 15 << 4;
    }
}