Fix texture distortion for flowing liquids (#9561)

Previously textures of the side faces on flowing liquid nodes would become distorted on different axis depending on the liquid level. This is because the nodes always had the same texture coordinates, even when the generated face could have different sizes. This solves that problem by adjusting the texture coordinates for the vertices making up the top of the faces, so the textures will not look compressed for smaller faces.
minetest · Apr 2, 2020 · 3d6b55d · 3d6b55d
1 parent d7825bc
commit 3d6b55d
Showing 1 changed file with 14 additions and 7 deletions.
diff --git a/src/client/content_mapblock.cpp b/src/client/content_mapblock.cpp
@@ -556,17 +556,24 @@ void MapblockMeshGenerator::drawLiquidSides()
 		for (int j = 0; j < 4; j++) {
 			const UV &vertex = base_vertices[j];
 			const v3s16 &base = face.p[vertex.u];
+			float v = vertex.v;
+
 			v3f pos;
-			pos.X = (base.X - 0.5) * BS;
-			pos.Z = (base.Z - 0.5) * BS;
-			if (vertex.v)
-				pos.Y = neighbor.is_same_liquid ? corner_levels[base.Z][base.X] : -0.5 * BS;
-			else
-				pos.Y =     !top_is_same_liquid ? corner_levels[base.Z][base.X] :  0.5 * BS;
+			pos.X = (base.X - 0.5f) * BS;
+			pos.Z = (base.Z - 0.5f) * BS;
+			if (vertex.v) {
+				pos.Y = neighbor.is_same_liquid ? corner_levels[base.Z][base.X] : -0.5f * BS;
+			} else if (top_is_same_liquid) {
+				pos.Y = 0.5f * BS;
+			} else {
+				pos.Y = corner_levels[base.Z][base.X];
+				v += (0.5f * BS - corner_levels[base.Z][base.X]) / BS;
+			}
+
 			if (data->m_smooth_lighting)
 				color = blendLightColor(pos);
 			pos += origin;
-			vertices[j] = video::S3DVertex(pos.X, pos.Y, pos.Z, 0, 0, 0, color, vertex.u, vertex.v);
+			vertices[j] = video::S3DVertex(pos.X, pos.Y, pos.Z, 0, 0, 0, color, vertex.u, v);
 		};
 		collector->append(tile_liquid, vertices, 4, quad_indices, 6);
 	}