2 files changed, 66 insertions, 0 deletions

diff --git a/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java b/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java
index da41927..4146900 100644
--- a/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java
+++ b/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java
@@ -1,5 +1,7 @@
 package com.anthonyhilyard.iceberg.util;
 
+import net.minecraft.util.text.Color;
+
 /**
  * Helper functions for smooth easing/interpolation.  If you need linear, use net.minecraft.util.math.MathHelper.lerp instead.
  */
@@ -8,6 +10,7 @@ public final class Easing
 	public static enum EasingType
 	{
 		None, // Produces step-wise interpolation.
+		Linear,
 		Quad,
 		Cubic
 	}
@@ -29,6 +32,19 @@ public final class Easing
 		return Ease(a, b, t, type, EasingDirection.InOut);
 	}
 
+	public static Color Ease(Color a, Color b, float t, EasingType type)
+	{
+		// Helper function to ease between colors.
+		// Ease each component individually.
+		int aV = a.getValue(), bV = b.getValue();
+		int aA = (aV >> 24) & 0xFF, aR = (aV >> 16) & 0xFF, aG = (aV >> 8) & 0xFF, aB = (aV >> 0) & 0xFF,
+			bA = (bV >> 24) & 0xFF, bR = (bV >> 16) & 0xFF, bG = (bV >> 8) & 0xFF, bB = (bV >> 0) & 0xFF;
+		return Color.fromRgb((int)Ease(aA, bA, t, type) << 24 |
+							 (int)Ease(aR, bR, t, type) << 16 |
+							 (int)Ease(aG, bG, t, type) << 8  |
+							 (int)Ease(aB, bB, t, type) << 0);
+	}
+
 	public static float Ease(float a, float b, float t, EasingType type, EasingDirection direction)
 	{
 		switch (type)
@@ -36,6 +52,8 @@ public final class Easing
 			case None:
 			default:
 				return None(a, b, t);
+			case Linear:
+				return Linear(a, b, t);
 			case Quad:
 				return Quad(a, b, t, direction);
 			case Cubic:
@@ -55,6 +73,11 @@ public final class Easing
 		}
 	}
 
+	private static float Linear(float a, float b, float t)
+	{
+		return a + (b - a) * t;
+	}
+
 	private static float Quad(float a, float b, float t, EasingDirection direction)
 	{
 		switch (direction)
diff --git a/src/main/java/com/anthonyhilyard/iceberg/util/GuiHelper.java b/src/main/java/com/anthonyhilyard/iceberg/util/GuiHelper.java
new file mode 100644
index 0000000..4325ebe
--- /dev/null
+++ b/src/main/java/com/anthonyhilyard/iceberg/util/GuiHelper.java
@@ -0,0 +1,43 @@
+package com.anthonyhilyard.iceberg.util;
+
+import org.lwjgl.opengl.GL11;
+import com.mojang.blaze3d.systems.RenderSystem;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.util.math.vector.Matrix4f;
+
+public class GuiHelper
+{
+	@SuppressWarnings("deprecation")
+	public static void drawGradientRectHorizontal(Matrix4f mat, int zLevel, int left, int top, int right, int bottom, int startColor, int endColor)
+	{
+		float startAlpha = (float)(startColor >> 24 & 255) / 255.0F;
+		float startRed   = (float)(startColor >> 16 & 255) / 255.0F;
+		float startGreen = (float)(startColor >>  8 & 255) / 255.0F;
+		float startBlue  = (float)(startColor       & 255) / 255.0F;
+		float endAlpha   = (float)(endColor   >> 24 & 255) / 255.0F;
+		float endRed     = (float)(endColor   >> 16 & 255) / 255.0F;
+		float endGreen   = (float)(endColor   >>  8 & 255) / 255.0F;
+		float endBlue    = (float)(endColor         & 255) / 255.0F;
+
+		RenderSystem.enableDepthTest();
+		RenderSystem.disableTexture();
+		RenderSystem.enableBlend();
+		RenderSystem.defaultBlendFunc();
+		RenderSystem.shadeModel(GL11.GL_SMOOTH);
+
+		Tessellator tessellator = Tessellator.getInstance();
+		BufferBuilder buffer = tessellator.getBuilder();
+		buffer.begin(GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR);
+		buffer.vertex(mat, right,    top, zLevel).color(  endRed,   endGreen,   endBlue,   endAlpha).endVertex();
+		buffer.vertex(mat,  left,    top, zLevel).color(startRed, startGreen, startBlue, startAlpha).endVertex();
+		buffer.vertex(mat,  left, bottom, zLevel).color(startRed, startGreen, startBlue, startAlpha).endVertex();
+		buffer.vertex(mat, right, bottom, zLevel).color(  endRed,   endGreen,   endBlue,   endAlpha).endVertex();
+		tessellator.end();
+
+		RenderSystem.shadeModel(GL11.GL_FLAT);
+		RenderSystem.disableBlend();
+		RenderSystem.enableTexture();
+	}
+}