From 49b65a5593c981a4ebc587538923e267a22c2437 Mon Sep 17 00:00:00 2001
From: number Zero <silverunicorn2011@yandex.ru>
Date: Mon, 29 Jan 2018 20:24:15 +0300
Subject: [PATCH] Fix liquid bottoms not being rendered

---
 src/content_mapblock.cpp | 27 +++++++++++++++++++++++++++
 src/content_mapblock.h   |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/src/content_mapblock.cpp b/src/content_mapblock.cpp
index 8edccf3de..69982c335 100644
--- a/src/content_mapblock.cpp
+++ b/src/content_mapblock.cpp
@@ -385,9 +385,16 @@ void MapblockMeshGenerator::prepareLiquidNodeDrawing()
 	getSpecialTile(1, &tile_liquid);
 
 	MapNode ntop = data->m_vmanip.getNodeNoEx(blockpos_nodes + v3s16(p.X, p.Y + 1, p.Z));
+	MapNode nbottom = data->m_vmanip.getNodeNoEx(blockpos_nodes + v3s16(p.X, p.Y - 1, p.Z));
 	c_flowing = nodedef->getId(f->liquid_alternative_flowing);
 	c_source = nodedef->getId(f->liquid_alternative_source);
 	top_is_same_liquid = (ntop.getContent() == c_flowing) || (ntop.getContent() == c_source);
+	draw_liquid_bottom = (nbottom.getContent() != c_flowing) && (nbottom.getContent() != c_source);
+	if (draw_liquid_bottom) {
+		const ContentFeatures &f2 = nodedef->get(nbottom.getContent());
+		if (f2.solidness > 1)
+			draw_liquid_bottom = false;
+	}
 
 	if (data->m_smooth_lighting)
 		return; // don't need to pre-compute anything in this case
@@ -595,6 +602,24 @@ void MapblockMeshGenerator::drawLiquidTop()
 	collector->append(tile_liquid_top, vertices, 4, quad_indices, 6);
 }
 
+void MapblockMeshGenerator::drawLiquidBottom()
+{
+	video::S3DVertex vertices[4] = {
+		video::S3DVertex(-BS / 2, -BS / 2, -BS / 2, 0, 0, 0, color_liquid_top, 0, 0),
+		video::S3DVertex( BS / 2, -BS / 2, -BS / 2, 0, 0, 0, color_liquid_top, 1, 0),
+		video::S3DVertex( BS / 2, -BS / 2,  BS / 2, 0, 0, 0, color_liquid_top, 1, 1),
+		video::S3DVertex(-BS / 2, -BS / 2,  BS / 2, 0, 0, 0, color_liquid_top, 0, 1),
+	};
+
+	for (int i = 0; i < 4; i++) {
+		if (data->m_smooth_lighting)
+			vertices[i].Color = blendLightColor(vertices[i].Pos);
+		vertices[i].Pos += origin;
+	}
+
+	collector->append(tile_liquid_top, vertices, 4, quad_indices, 6);
+}
+
 void MapblockMeshGenerator::drawLiquidNode()
 {
 	prepareLiquidNodeDrawing();
@@ -603,6 +628,8 @@ void MapblockMeshGenerator::drawLiquidNode()
 	drawLiquidSides();
 	if (!top_is_same_liquid)
 		drawLiquidTop();
+	if (draw_liquid_bottom)
+		drawLiquidBottom();
 }
 
 void MapblockMeshGenerator::drawGlasslikeNode()
diff --git a/src/content_mapblock.h b/src/content_mapblock.h
index 3d196aa99..ac3bda799 100644
--- a/src/content_mapblock.h
+++ b/src/content_mapblock.h
@@ -92,6 +92,7 @@ public:
 
 // liquid-specific
 	bool top_is_same_liquid;
+	bool draw_liquid_bottom;
 	TileSpec tile_liquid;
 	TileSpec tile_liquid_top;
 	content_t c_flowing;
@@ -112,6 +113,7 @@ public:
 	f32 getCornerLevel(int i, int k);
 	void drawLiquidSides();
 	void drawLiquidTop();
+	void drawLiquidBottom();
 
 // raillike-specific
 	// name of the group that enables connecting to raillike nodes of different kind
-- 
2.25.1