CrosshairTriangle.java

package slimeknights.tconstruct.library.client.crosshair;

import net.minecraft.client.Minecraft;
import net.minecraft.client.renderer.GlStateManager;
import net.minecraft.client.renderer.OpenGlHelper;
import net.minecraft.client.renderer.Tessellator;
import net.minecraft.client.renderer.VertexBuffer;
import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
import net.minecraft.util.ResourceLocation;

import org.lwjgl.opengl.GL11;

import slimeknights.tconstruct.library.Util;

public class CrosshairTriangle extends Crosshair {

  public CrosshairTriangle(ResourceLocation texture) {
    this(texture, 16);
  }

  public CrosshairTriangle(ResourceLocation texture, int size) {
    super(texture, size);
  }

  @Override
  protected void drawCrosshair(float spread, float width, float height, float partialTicks) {
    drawTipCrosshairPart(width/2f, height/2f - spread, 0);
    drawTipCrosshairPart(width/2f - spread, height/2f, 1);
    drawTipCrosshairPart(width/2f + spread, height/2f, 2);
    drawTipCrosshairPart(width/2f, height/2f + spread, 3);
  }

  private void drawTipCrosshairPart(double x, double y, int part)
  {
    final double s = 8d;
    final double z = -90;

    Tessellator tessellator = Tessellator.getInstance();
    VertexBuffer vb = tessellator.getBuffer();
    vb.begin(GL11.GL_TRIANGLES, DefaultVertexFormats.POSITION_TEX); // 4
    // top part
    if(part == 0) {
      vb.pos(x - s, y - s, z).tex(0, 0).endVertex();
      vb.pos(x, y, z).tex(0.5, 0.5).endVertex();
      vb.pos(x + s, y - s, z).tex(1, 0).endVertex();
    }
    // left part
    else if(part == 1) {
      vb.pos(x - s, y - s, z).tex(0, 0).endVertex();
      vb.pos(x - s, y + s, z).tex(0, 1).endVertex();
      vb.pos(x, y, z).tex(0.5, 0.5).endVertex();
    }
    // right part
    else if(part == 2) {
      vb.pos(x, y, z).tex(0.5, 0.5).endVertex();
      vb.pos(x + s, y + s, z).tex(1, 1).endVertex();
      vb.pos(x + s, y - s, z).tex(1, 0).endVertex();
    }
    // bottom part
    else if(part == 3) {
      vb.pos(x, y, z).tex( 0.5, 0.5).endVertex();
      vb.pos(x - s, y + s, z).tex(0, 1).endVertex();
      vb.pos(x + s, y + s, z).tex(1, 1).endVertex();
    }
    tessellator.draw();
  }
}