Tessellate faces into bigger chunks when texture repeating is an option.

This is kept conservative at just 2x2 cell sizes, because bigger polygons with more repeats will cause more texture warping and geometry glitching. This is already the biggest gain.

tesselate.cpp

@@ -4,6 +4,8 @@
 #include "gpc.h"
 #include "matrix.h"
 
+bool texture_isRepeatable(const miptex_t* miptex);
+
 std::vector<Tesselator::Polygon> Tesselator::tesselateFace(const face_t* face)
 {
 	std::vector<Polygon> polygons;
@@ -56,9 +58,11 @@ std::vector<Tesselator::Polygon> Tesselator::tesselateFace(const face_t* face)
 	}
 
 	// Create a virtual grid at the texture bounds and iterate over each cell to break up the face into repeating tiles
-	for (double y = floor(minT); y <= ceil(maxT); y += 1.0)
+	double cellSize = texture_isRepeatable(miptex) ? 2.0 : 1.0;
+
+	for (double y = floor(minT); y <= ceil(maxT); y += cellSize)
 	{
-		for (double x = floor(minS); x <= ceil(maxS); x += 1.0)
+		for (double x = floor(minS); x <= ceil(maxS); x += cellSize)
 		{
 			// Create a square polygon that covers the entire cell
 			gpc_polygon cell = { 0 };
@@ -66,9 +70,9 @@ std::vector<Tesselator::Polygon> Tesselator::tesselateFace(const face_t* face)
 			cell_bounds.num_vertices = 4;
 			cell_bounds.vertex = (gpc_vertex*)malloc(4 * sizeof(gpc_vertex));
 			cell_bounds.vertex[0] = gpc_vertex{ x, y };
-			cell_bounds.vertex[1] = gpc_vertex{ x, y + 1.0 };
-			cell_bounds.vertex[2] = gpc_vertex{ x + 1.0, y + 1.0 };
-			cell_bounds.vertex[3] = gpc_vertex{ x + 1.0, y };
+			cell_bounds.vertex[1] = gpc_vertex{ x, y + cellSize };
+			cell_bounds.vertex[2] = gpc_vertex{ x + cellSize, y + cellSize };
+			cell_bounds.vertex[3] = gpc_vertex{ x + cellSize, y };
 			gpc_add_contour(&cell, &cell_bounds, 0);
 
 			// Take the intersection to get the chunk of the face that's inside this cell

texture.cpp

@@ -350,7 +350,10 @@ bool process_textures(const world_t* world, TextureList& outTextures)
 				tex.ps1tex.tpage = getTPage(outTim.format, 0, x, y);
 				tex.uoffs = (u_char)((x % 64) << (2 - outTim.format));
 				tex.voffs = (u_char)(y & 0xFF);
+				if (texture_isRepeatable(miptex))
 					tex.ps1tex.twin = getTexWindow(tex.uoffs, tex.voffs, tex.w, tex.h);	// TODO: figure out the right offsets that are multiples of w and h; NOTE: if uoffs has to >> 1, then w probably has to as well
+				else
+					tex.ps1tex.twin = getTexWindow(0, 0, 0, 0);
 			}
 		}
 
@@ -412,7 +415,7 @@ bool process_textures(const world_t* world, TextureList& outTextures)
 	return true;
 }
 
-bool texture_isRepeatable(miptex_t* miptex)
+bool texture_isRepeatable(const miptex_t* miptex)
 {
 	// Check if the texture is square
 	if (miptex->width != miptex->height)

texture.h

@@ -25,4 +25,4 @@ struct TextureDescriptor
 typedef std::vector<TextureDescriptor> TextureList;
 
 bool process_textures(const world_t* world, TextureList& outTextures);
-bool texture_isRepeatable(miptex_t* miptex);
+bool texture_isRepeatable(const miptex_t* miptex);