Improve tiled NinePatchBackgroundPainter performance (#185)

* Improve tiled NinePatchBackgroundPainter performance

* Use Fabric API's CoreShaderRegistrationCallback

* Switch to LibNinePatch release build

* Rename libgui:tiled -> libgui:tiled_rectangle

* Fix grammar

3 files changed, 81 insertions, 0 deletions

diff --git a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiClient.java b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiClient.java
index 6bc69fe..526fe96 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiClient.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiClient.java
@@ -30,6 +30,8 @@ public class LibGuiClient implements ClientModInitializer {
 		ClientPlayNetworking.registerGlobalReceiver(ScreenNetworkingImpl.SCREEN_MESSAGE_S2C, (client, networkHandler, buf, responseSender) -> {
 			ScreenNetworkingImpl.handle(client, client.player, buf);
 		});
+
+		LibGuiShaders.register();
 	}
 
 	public static LibGuiConfig loadConfig() {
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiShaders.java b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiShaders.java
new file mode 100644
index 0000000..fbbad66
--- /dev/null
+++ b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/LibGuiShaders.java
@@ -0,0 +1,33 @@
+package io.github.cottonmc.cotton.gui.impl.client;
+
+import net.fabricmc.fabric.api.client.rendering.v1.CoreShaderRegistrationCallback;
+import net.minecraft.client.gl.ShaderProgram;
+import net.minecraft.client.render.VertexFormats;
+import net.minecraft.util.Identifier;
+
+import io.github.cottonmc.cotton.gui.impl.LibGuiCommon;
+import org.jetbrains.annotations.Nullable;
+
+public final class LibGuiShaders {
+	private static @Nullable ShaderProgram tiledRectangle;
+
+	static void register() {
+		CoreShaderRegistrationCallback.EVENT.register(context -> {
+			// Register our core shaders.
+			// The tiled rectangle shader is used for performant tiled texture rendering.
+			context.register(new Identifier(LibGuiCommon.MOD_ID, "tiled_rectangle"), VertexFormats.POSITION, program -> tiledRectangle = program);
+		});
+	}
+
+	private static ShaderProgram assertPresent(ShaderProgram program, String name) {
+		if (program == null) {
+			throw new NullPointerException("Shader libgui:" + name + " not initialised!");
+		}
+
+		return program;
+	}
+
+	public static ShaderProgram getTiledRectangle() {
+		return assertPresent(tiledRectangle, "tiled_rectangle");
+	}
+}
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NinePatchTextureRendererImpl.java b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NinePatchTextureRendererImpl.java
index 7161373..9227f94 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NinePatchTextureRendererImpl.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/impl/client/NinePatchTextureRendererImpl.java
@@ -1,10 +1,20 @@
 package io.github.cottonmc.cotton.gui.impl.client;
 
+import com.mojang.blaze3d.systems.RenderCall;
+import com.mojang.blaze3d.systems.RenderSystem;
+import net.minecraft.client.gl.ShaderProgram;
+import net.minecraft.client.render.BufferBuilder;
+import net.minecraft.client.render.BufferRenderer;
+import net.minecraft.client.render.Tessellator;
+import net.minecraft.client.render.VertexFormat;
+import net.minecraft.client.render.VertexFormats;
 import net.minecraft.client.util.math.MatrixStack;
 import net.minecraft.util.Identifier;
 
 import io.github.cottonmc.cotton.gui.client.ScreenDrawing;
 import juuxel.libninepatch.ContextualTextureRenderer;
+import org.jetbrains.annotations.Nullable;
+import org.joml.Matrix4f;
 
 /**
  * An implementation of LibNinePatch's {@link ContextualTextureRenderer} for identifiers.
@@ -16,4 +26,40 @@ public enum NinePatchTextureRendererImpl implements ContextualTextureRenderer<Id
 	public void draw(Identifier texture, MatrixStack matrices, int x, int y, int width, int height, float u1, float v1, float u2, float v2) {
 		ScreenDrawing.texturedRect(matrices, x, y, width, height, texture, u1, v1, u2, v2, 0xFF_FFFFFF);
 	}
+
+	@Override
+	public void drawTiled(Identifier texture, MatrixStack matrices, int x, int y, int regionWidth, int regionHeight, int tileWidth, int tileHeight, float u1, float v1, float u2, float v2) {
+		RenderSystem.setShader(LibGuiShaders::getTiledRectangle);
+		RenderSystem.setShaderTexture(0, texture);
+		RenderSystem.setShaderColor(1, 1, 1, 1);
+		Matrix4f positionMatrix = matrices.peek().getPositionMatrix();
+		onRenderThread(() -> {
+			@Nullable ShaderProgram program = RenderSystem.getShader();
+			if (program != null) {
+				program.getUniformOrDefault("LibGuiRectanglePos").set((float) x, (float) y);
+				program.getUniformOrDefault("LibGuiTileDimensions").set((float) tileWidth, (float) tileHeight);
+				program.getUniformOrDefault("LibGuiTileUvs").set(u1, v1, u2, v2);
+				program.getUniformOrDefault("LibGuiPositionMatrix").set(positionMatrix);
+			}
+		});
+
+		Tessellator tessellator = Tessellator.getInstance();
+		BufferBuilder buffer = tessellator.getBuffer();
+		RenderSystem.enableBlend();
+		buffer.begin(VertexFormat.DrawMode.QUADS, VertexFormats.POSITION);
+		buffer.vertex(positionMatrix, x, y, 0).next();
+		buffer.vertex(positionMatrix, x, y + regionHeight, 0).next();
+		buffer.vertex(positionMatrix, x + regionWidth, y + regionHeight, 0).next();
+		buffer.vertex(positionMatrix, x + regionWidth, y, 0).next();
+		BufferRenderer.drawWithGlobalProgram(buffer.end());
+		RenderSystem.disableBlend();
+	}
+
+	private static void onRenderThread(RenderCall renderCall) {
+		if (RenderSystem.isOnRenderThread()) {
+			renderCall.execute();
+		} else {
+			RenderSystem.recordRenderCall(renderCall);
+		}
+	}
 }