Add texture flipping support for negative Y faces

Introduced a utility method to determine if textures need flipping based on texture groups and block bounds. Updated rendering functions to use this logic, ensuring correct texture orientation for specific cases.
Corrected UV coordinates for the negative y face rendering. These changes ensure proper texture alignment for bottom sides when using ambient occlusion (AO) and regular rendering.

Author: ICaxapI

src/main/java/gregapi/data/CS.java

@@ -2326,4 +2326,11 @@ public static class SFX {
 
 	, RES_PATH_IC2              = MD.IC2.mID.toLowerCase() + ":"
 	;
+
+	public static final HashSet<String> SHOULD_FLIP_NEG_Y_TEXTURES = new HashSet<>();
+
+	static {
+		SHOULD_FLIP_NEG_Y_TEXTURES.add("machines");
+		SHOULD_FLIP_NEG_Y_TEXTURES.add("overlays");
+	}
 }

src/main/java/gregapi/render/ITexture.java

@@ -20,6 +20,7 @@
 package gregapi.render;
 
 import static gregapi.data.CS.*;
+import static gregapi.util.UT.shouldFlipNegYTextures;
 
 import org.lwjgl.opengl.GL11;
 
@@ -248,11 +249,11 @@ public static boolean doRenderYNeg(IIcon aIcon, RenderBlocks aRenderer, Block aB
 			if (aBlock.getRenderBlockPass() > 0) {
 				double tOldValue = aRenderer.renderMinY;
 				aRenderer.renderMinY -= (aRenderer.renderFromInside?-1:+1)*OFFSET_Y_NEG;
-				renderFixedNegativeYFacing(aIcon, aRenderer, aBlock, aX, aY, aZ);
+				renderFixedNegativeYFacing(aIcon, aRenderer, aBlock, aX, aY, aZ, aChangedBlockBounds);
 				aRenderer.renderMinY = tOldValue;
 				OFFSET_Y_NEG += OFFSET_ADD;
 			} else {
-				renderFixedNegativeYFacing(aIcon, aRenderer, aBlock, aX, aY, aZ);
+				renderFixedNegativeYFacing(aIcon, aRenderer, aBlock, aX, aY, aZ, aChangedBlockBounds);
 			}
 			return T;
 		}
@@ -285,13 +286,15 @@ public static boolean doRenderZNeg(IIcon aIcon, RenderBlocks aRenderer, Block aB
 			return T;
 		}
 
-		public static void renderFixedNegativeYFacing(IIcon aIcon, RenderBlocks aRenderer, Block aBlock, int aX, int aY, int aZ) {
+		public static void renderFixedNegativeYFacing(IIcon aIcon, RenderBlocks aRenderer, Block aBlock, int aX, int aY, int aZ, boolean aChangedBlockBounds) {
 			if (aRenderer.hasOverrideBlockTexture()) aIcon = aRenderer.overrideBlockTexture;
 		//  double tMaxX1 = aIcon.getInterpolatedU(aRenderer.renderMaxX * 16.0);
 		//  double tMinX1 = aIcon.getInterpolatedU(aRenderer.renderMinX * 16.0);
 		//  double tMaxZ1 = aIcon.getInterpolatedV(aRenderer.renderMinZ * 16.0);
 		//  double tMinZ1 = aIcon.getInterpolatedV(aRenderer.renderMaxZ * 16.0);
-			
+
+			boolean shouldFlipTexture = shouldFlipNegYTextures(aIcon.getIconName(), aChangedBlockBounds);
+
 			double tMaxX1 = aIcon.getInterpolatedU(aRenderer.renderMaxX * 16.0);
 			double tMinX1 = aIcon.getInterpolatedU(aRenderer.renderMinX * 16.0);
 			double tMaxZ1 = aIcon.getInterpolatedV(aRenderer.renderMaxZ * 16.0);
@@ -358,21 +361,21 @@ public static void renderFixedNegativeYFacing(IIcon aIcon, RenderBlocks aRendere
 			if (aRenderer.enableAO) {
 				Tessellator.instance.setColorOpaque_F(aRenderer.colorRedTopLeft, aRenderer.colorGreenTopLeft, aRenderer.colorBlueTopLeft);
 				Tessellator.instance.setBrightness(aRenderer.brightnessTopLeft);
-				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMaxZ3, tMinX2, tMinZ2);
+				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMaxZ3, tMinX2, shouldFlipTexture ? tMinZ2 : tMaxZ2);
 				Tessellator.instance.setColorOpaque_F(aRenderer.colorRedBottomLeft, aRenderer.colorGreenBottomLeft, aRenderer.colorBlueBottomLeft);
 				Tessellator.instance.setBrightness(aRenderer.brightnessBottomLeft);
-				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMinZ3, tMinX1, tMaxZ1);
+				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMinZ3, tMinX1, shouldFlipTexture ? tMaxZ1 : tMinZ1);
 				Tessellator.instance.setColorOpaque_F(aRenderer.colorRedBottomRight, aRenderer.colorGreenBottomRight, aRenderer.colorBlueBottomRight);
 				Tessellator.instance.setBrightness(aRenderer.brightnessBottomRight);
-				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMinZ3, tMaxX2, tMaxZ2);
+				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMinZ3, tMaxX2, shouldFlipTexture ? tMaxZ2 : tMinZ2);
 				Tessellator.instance.setColorOpaque_F(aRenderer.colorRedTopRight, aRenderer.colorGreenTopRight, aRenderer.colorBlueTopRight);
 				Tessellator.instance.setBrightness(aRenderer.brightnessTopRight);
-				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMaxZ3, tMaxX1, tMinZ1);
+				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMaxZ3, tMaxX1, shouldFlipTexture ? tMinZ1 : tMaxZ1);
 			} else {
-				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMaxZ3, tMinX2, tMinZ2);
-				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMinZ3, tMinX1, tMaxZ1);
-				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMinZ3, tMaxX2, tMaxZ2);
-				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMaxZ3, tMaxX1, tMinZ1);
+				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMaxZ3, tMinX2, shouldFlipTexture ? tMinZ2 : tMaxZ2);
+				Tessellator.instance.addVertexWithUV(tMinX3, tMinY3, tMinZ3, tMinX1, shouldFlipTexture ? tMaxZ1 : tMinZ1);
+				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMinZ3, tMaxX2, shouldFlipTexture ? tMaxZ2 : tMinZ2);
+				Tessellator.instance.addVertexWithUV(tMaxX3, tMinY3, tMaxZ3, tMaxX1, shouldFlipTexture ? tMinZ1 : tMaxZ1);
 			}
 		}
 

src/main/java/gregapi/util/UT.java

@@ -3568,4 +3568,14 @@ public static boolean finish() {
 			return F;
 		}
 	}
+
+	public static boolean shouldFlipNegYTextures(String textureName, boolean aChangedBlockBounds){
+		int start = textureName.indexOf(":");
+		int stop = textureName.indexOf("/");
+		if (start != -1 && stop != -1) {
+			String textureGroup = textureName.substring(start + 1, stop);
+			return aChangedBlockBounds && (SHOULD_FLIP_NEG_Y_TEXTURES.contains(textureGroup)); // dirty hack, but works fine
+		}
+		return false;
+	}
 }