From abe5d3185f25a119d3e863f5734aaeefa57cfdd8 Mon Sep 17 00:00:00 2001
From: Ykkrosh <philip@wildfiregames.com>
Date: Fri, 12 Feb 2010 12:01:46 +0000
Subject: [PATCH] Fix crash when constructing buildings off the edge of the map

This was SVN commit r7320.
---
 source/graphics/Terrain.cpp          |  4 +-
 source/graphics/tests/test_Terrain.h | 59 ++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/source/graphics/Terrain.cpp b/source/graphics/Terrain.cpp
index 54999f3247..2c556d2f81 100644
--- a/source/graphics/Terrain.cpp
+++ b/source/graphics/Terrain.cpp
@@ -505,11 +505,11 @@ float CTerrain::FlattenArea(float x0, float x1, float z0, float z1)
 	for (ssize_t z=tz0;z<=tz1;z++) {
 		for (ssize_t x=tx0;x<=tx1;x++) {
 			m_Heightmap[z*m_MapSize + x]=avgY;
-			CPatch* patch=GetPatch(x/PATCH_SIZE,z/PATCH_SIZE);	// can't fail (x,z were clamped)
-			patch->SetDirty(RENDERDATA_UPDATE_VERTICES);
 		}
 	}
 
+	MakeDirty(tx0, tz0, tx1, tz1, RENDERDATA_UPDATE_VERTICES);
+
 	return avgY*HEIGHT_SCALE;
 }
 
diff --git a/source/graphics/tests/test_Terrain.h b/source/graphics/tests/test_Terrain.h
index 7d1a922e44..eaf74e3b2a 100644
--- a/source/graphics/tests/test_Terrain.h
+++ b/source/graphics/tests/test_Terrain.h
@@ -19,6 +19,7 @@
 
 #include "graphics/Terrain.h"
 
+#include "graphics/Patch.h"
 #include "graphics/RenderableObject.h"
 #include "maths/FixedVector3D.h"
 
@@ -30,6 +31,11 @@ class TestTerrain : public CxxTest::TestSuite
 		terrain.MakeDirty(RENDERDATA_UPDATE_VERTICES);
 	}
 
+	u16 GetVertex(CTerrain& terrain, ssize_t i, ssize_t j)
+	{
+		return terrain.GetHeightMap()[j*terrain.GetVerticesPerSide() + i];
+	}
+
 	void Set45Slope(CTerrain& terrain)
 	{
 		SetVertex(terrain, 0, 0, 100);
@@ -95,4 +101,57 @@ public:
 		TS_ASSERT_EQUALS(vec.Y.ToFloat(), 1.f);
 		TS_ASSERT_EQUALS(vec.Z.ToFloat(), 0.f);
 	}
+
+	void test_FlattenArea()
+	{
+		CTerrain terrain;
+		terrain.Initialize(4, NULL);
+		size_t m = terrain.GetVerticesPerSide() - 1;
+		SetVertex(terrain, 0, 0, 25600);
+		SetVertex(terrain, 2, 3, 25600);
+		SetVertex(terrain, m, m, 25600);
+
+		terrain.FlattenArea(-1000, 1000, -1000, 1000);
+
+		// (25600*3) / (65*65) = 18
+		TS_ASSERT_EQUALS(GetVertex(terrain, 0, 0), 18);
+		TS_ASSERT_EQUALS(GetVertex(terrain, 4, 5), 18);
+		TS_ASSERT_EQUALS(GetVertex(terrain, m, m), 18);
+	}
+
+	void test_FlattenArea_dirty()
+	{
+		CTerrain terrain;
+		terrain.Initialize(4, NULL);
+
+		for (ssize_t pj = 0; pj < terrain.GetPatchesPerSide(); ++pj)
+			for (ssize_t pi = 0; pi < terrain.GetPatchesPerSide(); ++pi)
+				terrain.GetPatch(pi, pj)->SetRenderData(new CRenderData());
+
+#define EXPECT_DIRTY(which, pi, pj) TS_ASSERT_EQUALS((bool)(terrain.GetPatch(pi, pj)->GetRenderData()->m_UpdateFlags & RENDERDATA_UPDATE_VERTICES), which)
+
+		EXPECT_DIRTY(false, 0, 0);
+		EXPECT_DIRTY(false, 1, 0);
+		EXPECT_DIRTY(false, 2, 0);
+		EXPECT_DIRTY(false, 0, 1);
+		EXPECT_DIRTY(false, 1, 1);
+		EXPECT_DIRTY(false, 2, 1);
+		EXPECT_DIRTY(false, 0, 2);
+		EXPECT_DIRTY(false, 1, 2);
+		EXPECT_DIRTY(false, 2, 2);
+
+		terrain.FlattenArea(PATCH_SIZE*CELL_SIZE, 2*PATCH_SIZE*CELL_SIZE, PATCH_SIZE*CELL_SIZE+1, 2*PATCH_SIZE*CELL_SIZE-1);
+
+		EXPECT_DIRTY(true, 0, 0);
+		EXPECT_DIRTY(true, 1, 0);
+		EXPECT_DIRTY(true, 2, 0);
+		EXPECT_DIRTY(true, 0, 1);
+		EXPECT_DIRTY(true, 1, 1);
+		EXPECT_DIRTY(true, 2, 1);
+		EXPECT_DIRTY(true, 0, 2);
+		EXPECT_DIRTY(true, 1, 2);
+		EXPECT_DIRTY(true, 2, 2);
+		// This is dirtying more than strictly necessary, but that's okay
+	}
+
 };