Add b3GridClothMesh. Set particle friction to global cloth friction. Update the tests. Also simplified some code.

include/bounce/bounce.h

@@ -64,6 +64,7 @@
 #include <bounce/rope/rope.h>
 
 #include <bounce/cloth/cloth_mesh.h>
+#include <bounce/cloth/grid_cloth_mesh.h>
 #include <bounce/cloth/cloth.h>
 #include <bounce/cloth/particle.h>
 #include <bounce/cloth/cloth_triangle.h>

include/bounce/cloth/grid_cloth_mesh.h

@@ -0,0 +1,96 @@
+/*
+* Copyright (c) 2016-2019 Irlan Robson https://irlanrobson.github.io
+*
+* This software is provided 'as-is', without any express or implied
+* warranty.  In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 1. The origin of this software must not be misrepresented; you must not
+* claim that you wrote the original software. If you use this software
+* in a product, an acknowledgment in the product documentation would be
+* appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+* misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+*/
+
+#ifndef B3_GRID_CLOTH_MESH_H
+#define B3_GRID_CLOTH_MESH_H
+
+#include <bounce/cloth/cloth_mesh.h>
+
+// A (H + 1) x (W + 1) grid mesh stored in row-major order.
+// v(i, j) = i + (W + 1) + j
+template<u32 W = 1, u32 H = 1>
+struct b3GridClothMesh : public b3ClothMesh
+{
+	b3Vec3 gridVertices[(H + 1) * (W + 1)];
+	b3ClothMeshTriangle gridTriangles[2 * H * W];
+	b3ClothMeshMesh gridMesh;
+
+	// Set this grid to a W (width) per H (height) dimensioned grid centered at the origin and aligned
+	// with the world x-z axes.
+	b3GridClothMesh()
+	{
+		vertexCount = 0;
+		for (u32 i = 0; i <= H; ++i)
+		{
+			for (u32 j = 0; j <= W; ++j)
+			{
+				gridVertices[vertexCount++].Set(float32(j), 0.0f, float32(i));
+			}
+		}
+
+		B3_ASSERT(vertexCount == (W + 1) * (H + 1));
+		
+		b3Vec3 translation;
+		translation.x = -0.5f * float32(W);
+		translation.y = 0.0f;
+		translation.z = -0.5f * float32(H);
+
+		for (u32 i = 0; i < vertexCount; ++i)
+		{
+			gridVertices[i] += translation;
+		}
+
+		triangleCount = 0;
+		for (u32 i = 0; i < H; ++i)
+		{
+			for (u32 j = 0; j < W; ++j)
+			{
+				u32 v1 = i * (W + 1) + j;
+				u32 v2 = (i + 1) * (W + 1) + j;
+				u32 v3 = (i + 1) * (W + 1) + (j + 1);
+				u32 v4 = i * (W + 1) + (j + 1);
+
+				b3ClothMeshTriangle* t1 = gridTriangles + triangleCount++;
+				t1->v1 = v3;
+				t1->v2 = v2;
+				t1->v3 = v1;
+
+				b3ClothMeshTriangle* t2 = gridTriangles + triangleCount++;
+				t2->v1 = v1;
+				t2->v2 = v4;
+				t2->v3 = v3;
+			}
+		}
+		
+		B3_ASSERT(triangleCount == 2 * H * W);
+
+		gridMesh.startTriangle = 0;
+		gridMesh.triangleCount = triangleCount;
+		gridMesh.startVertex = 0;
+		gridMesh.vertexCount = vertexCount;
+
+		vertices = gridVertices;
+		triangles = gridTriangles;
+		meshCount = 1;
+		meshes = &gridMesh;
+		sewingLineCount = 0;
+		sewingLines = nullptr;
+	}
+};
+
+#endif

include/bounce/collision/shapes/grid_mesh.h

@@ -22,6 +22,7 @@
 #include <bounce/collision/shapes/mesh.h>
 
 // A (H + 1) x (W + 1) grid mesh stored in row-major order.
+// v(i, j) = i * (W + 1) + j
 template<u32 H = 1, u32 W = 1>
 struct b3GridMesh : public b3Mesh
 {
@@ -32,61 +33,53 @@ struct b3GridMesh : public b3Mesh
 	// with the world x-z axes.
 	b3GridMesh()
 	{
-		u32 h = H + 1;
-		u32 w = W + 1;
-
-		b3Vec3 t;
-		t.x = -0.5f * float32(w) + 0.5f;
-		t.y = 0.0f;
-		t.z = -0.5f * float32(h) + 0.5f;
-
-		for (u32 i = 0; i < h; ++i)
+		vertexCount = 0;
+		for (u32 i = 0; i <= H; ++i)
 		{
-			for (u32 j = 0; j < w; ++j)
+			for (u32 j = 0; j <= W; ++j)
 			{
-				u32 v1 = i * w + j;
-
-				b3Vec3 v;
-				v.x = float32(j);
-				v.y = 0.0f;
-				v.z = float32(i);
-
-				v += t;
-
-				gridVertices[v1] = v;
+				gridVertices[vertexCount++].Set(float32(j), 0.0f, float32(i));
 			}
 		}
 
-		u32 triangleIndex = 0;
-		for (u32 i = 0; i < h - 1; ++i)
+		B3_ASSERT(vertexCount == (H + 1) * (W + 1));
+
+		b3Vec3 translation;
+		translation.x = -0.5f * float32(W);
+		translation.y = 0.0f;
+		translation.z = -0.5f * float32(H);
+
+		for (u32 i = 0; i < vertexCount; ++i)
 		{
-			for (u32 j = 0; j < w - 1; ++j)
+			gridVertices[i] += translation;
+		}
+
+		triangleCount = 0;
+		for (u32 i = 0; i < H; ++i)
+		{
+			for (u32 j = 0; j < W; ++j)
 			{
-				u32 v1 = i * w + j;
-				u32 v2 = (i + 1) * w + j;
-				u32 v3 = (i + 1) * w + (j + 1);
-				u32 v4 = i * w + (j + 1);
-
-				b3Triangle* t1 = gridTriangles + triangleIndex;
-				++triangleIndex;
+				u32 v1 = i * (W + 1) + j;
+				u32 v2 = (i + 1) * (W + 1) + j;
+				u32 v3 = (i + 1) * (W + 1) + (j + 1);
+				u32 v4 = i * (W + 1) + (j + 1);
 
+				b3Triangle* t1 = gridTriangles + triangleCount++;
 				t1->v1 = v3;
 				t1->v2 = v2;
 				t1->v3 = v1;
 
-				b3Triangle* t2 = gridTriangles + triangleIndex;
-				++triangleIndex;
-
+				b3Triangle* t2 = gridTriangles + triangleCount++;
 				t2->v1 = v1;
 				t2->v2 = v4;
 				t2->v3 = v3;
 			}
 		}
 
+		B3_ASSERT(triangleCount == 2 * H * W);
+
 		vertices = gridVertices;
-		vertexCount = (H + 1) * (W + 1);
 		triangles = gridTriangles;
-		triangleCount = 2 * H * W;
 	}
 };
 

include/bounce/softbody/block_softbody_mesh.h

@@ -36,7 +36,7 @@ struct b3BlockSoftBodyMesh : public b3SoftBodyMesh
 			{
 				for (u32 z = 0; z <= D; ++z)
 				{
-					blockVertices[vertexCount++].Set(x, y, z);
+					blockVertices[vertexCount++].Set(float32(x), float32(y), float32(z));
 				}
 			}
 		}

include/bounce/softbody/softbody.h

@@ -141,7 +141,7 @@ public:
 	// Debug draw the body using the associated mesh.
 	void Draw() const;
 private:
-	friend class b3SoftBodyNode;
+	friend struct b3SoftBodyNode;
 	friend class b3SoftBodySolver;
 	friend class b3SoftBodyForceSolver;