diff options
author | chai <chaifix@163.com> | 2019-03-19 23:06:27 +0800 |
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committer | chai <chaifix@163.com> | 2019-03-19 23:06:27 +0800 |
commit | 1497dccd63a84b7ee2b229b1ad9c5c02718f2a78 (patch) | |
tree | f8d1bff50da13e126d08c7345653e002e293202d /Source/3rdParty/Box2D/Collision/b2CollidePolygon.cpp | |
parent | 5e2a973516e0729b225da9de0b03015dc5854ac4 (diff) |
*rename
Diffstat (limited to 'Source/3rdParty/Box2D/Collision/b2CollidePolygon.cpp')
-rw-r--r-- | Source/3rdParty/Box2D/Collision/b2CollidePolygon.cpp | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/Source/3rdParty/Box2D/Collision/b2CollidePolygon.cpp b/Source/3rdParty/Box2D/Collision/b2CollidePolygon.cpp deleted file mode 100644 index 10211e7..0000000 --- a/Source/3rdParty/Box2D/Collision/b2CollidePolygon.cpp +++ /dev/null @@ -1,239 +0,0 @@ -/* -* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org -* -* 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. -*/ - -#include "Box2D/Collision/b2Collision.h" -#include "Box2D/Collision/Shapes/b2PolygonShape.h" - -// Find the max separation between poly1 and poly2 using edge normals from poly1. -static float32 b2FindMaxSeparation(int32* edgeIndex, - const b2PolygonShape* poly1, const b2Transform& xf1, - const b2PolygonShape* poly2, const b2Transform& xf2) -{ - int32 count1 = poly1->m_count; - int32 count2 = poly2->m_count; - const b2Vec2* n1s = poly1->m_normals; - const b2Vec2* v1s = poly1->m_vertices; - const b2Vec2* v2s = poly2->m_vertices; - b2Transform xf = b2MulT(xf2, xf1); - - int32 bestIndex = 0; - float32 maxSeparation = -b2_maxFloat; - for (int32 i = 0; i < count1; ++i) - { - // Get poly1 normal in frame2. - b2Vec2 n = b2Mul(xf.q, n1s[i]); - b2Vec2 v1 = b2Mul(xf, v1s[i]); - - // Find deepest point for normal i. - float32 si = b2_maxFloat; - for (int32 j = 0; j < count2; ++j) - { - float32 sij = b2Dot(n, v2s[j] - v1); - if (sij < si) - { - si = sij; - } - } - - if (si > maxSeparation) - { - maxSeparation = si; - bestIndex = i; - } - } - - *edgeIndex = bestIndex; - return maxSeparation; -} - -static void b2FindIncidentEdge(b2ClipVertex c[2], - const b2PolygonShape* poly1, const b2Transform& xf1, int32 edge1, - const b2PolygonShape* poly2, const b2Transform& xf2) -{ - const b2Vec2* normals1 = poly1->m_normals; - - int32 count2 = poly2->m_count; - const b2Vec2* vertices2 = poly2->m_vertices; - const b2Vec2* normals2 = poly2->m_normals; - - b2Assert(0 <= edge1 && edge1 < poly1->m_count); - - // Get the normal of the reference edge in poly2's frame. - b2Vec2 normal1 = b2MulT(xf2.q, b2Mul(xf1.q, normals1[edge1])); - - // Find the incident edge on poly2. - int32 index = 0; - float32 minDot = b2_maxFloat; - for (int32 i = 0; i < count2; ++i) - { - float32 dot = b2Dot(normal1, normals2[i]); - if (dot < minDot) - { - minDot = dot; - index = i; - } - } - - // Build the clip vertices for the incident edge. - int32 i1 = index; - int32 i2 = i1 + 1 < count2 ? i1 + 1 : 0; - - c[0].v = b2Mul(xf2, vertices2[i1]); - c[0].id.cf.indexA = (uint8)edge1; - c[0].id.cf.indexB = (uint8)i1; - c[0].id.cf.typeA = b2ContactFeature::e_face; - c[0].id.cf.typeB = b2ContactFeature::e_vertex; - - c[1].v = b2Mul(xf2, vertices2[i2]); - c[1].id.cf.indexA = (uint8)edge1; - c[1].id.cf.indexB = (uint8)i2; - c[1].id.cf.typeA = b2ContactFeature::e_face; - c[1].id.cf.typeB = b2ContactFeature::e_vertex; -} - -// Find edge normal of max separation on A - return if separating axis is found -// Find edge normal of max separation on B - return if separation axis is found -// Choose reference edge as min(minA, minB) -// Find incident edge -// Clip - -// The normal points from 1 to 2 -void b2CollidePolygons(b2Manifold* manifold, - const b2PolygonShape* polyA, const b2Transform& xfA, - const b2PolygonShape* polyB, const b2Transform& xfB) -{ - manifold->pointCount = 0; - float32 totalRadius = polyA->m_radius + polyB->m_radius; - - int32 edgeA = 0; - float32 separationA = b2FindMaxSeparation(&edgeA, polyA, xfA, polyB, xfB); - if (separationA > totalRadius) - return; - - int32 edgeB = 0; - float32 separationB = b2FindMaxSeparation(&edgeB, polyB, xfB, polyA, xfA); - if (separationB > totalRadius) - return; - - const b2PolygonShape* poly1; // reference polygon - const b2PolygonShape* poly2; // incident polygon - b2Transform xf1, xf2; - int32 edge1; // reference edge - uint8 flip; - const float32 k_tol = 0.1f * b2_linearSlop; - - if (separationB > separationA + k_tol) - { - poly1 = polyB; - poly2 = polyA; - xf1 = xfB; - xf2 = xfA; - edge1 = edgeB; - manifold->type = b2Manifold::e_faceB; - flip = 1; - } - else - { - poly1 = polyA; - poly2 = polyB; - xf1 = xfA; - xf2 = xfB; - edge1 = edgeA; - manifold->type = b2Manifold::e_faceA; - flip = 0; - } - - b2ClipVertex incidentEdge[2]; - b2FindIncidentEdge(incidentEdge, poly1, xf1, edge1, poly2, xf2); - - int32 count1 = poly1->m_count; - const b2Vec2* vertices1 = poly1->m_vertices; - - int32 iv1 = edge1; - int32 iv2 = edge1 + 1 < count1 ? edge1 + 1 : 0; - - b2Vec2 v11 = vertices1[iv1]; - b2Vec2 v12 = vertices1[iv2]; - - b2Vec2 localTangent = v12 - v11; - localTangent.Normalize(); - - b2Vec2 localNormal = b2Cross(localTangent, 1.0f); - b2Vec2 planePoint = 0.5f * (v11 + v12); - - b2Vec2 tangent = b2Mul(xf1.q, localTangent); - b2Vec2 normal = b2Cross(tangent, 1.0f); - - v11 = b2Mul(xf1, v11); - v12 = b2Mul(xf1, v12); - - // Face offset. - float32 frontOffset = b2Dot(normal, v11); - - // Side offsets, extended by polytope skin thickness. - float32 sideOffset1 = -b2Dot(tangent, v11) + totalRadius; - float32 sideOffset2 = b2Dot(tangent, v12) + totalRadius; - - // Clip incident edge against extruded edge1 side edges. - b2ClipVertex clipPoints1[2]; - b2ClipVertex clipPoints2[2]; - int np; - - // Clip to box side 1 - np = b2ClipSegmentToLine(clipPoints1, incidentEdge, -tangent, sideOffset1, iv1); - - if (np < 2) - return; - - // Clip to negative box side 1 - np = b2ClipSegmentToLine(clipPoints2, clipPoints1, tangent, sideOffset2, iv2); - - if (np < 2) - { - return; - } - - // Now clipPoints2 contains the clipped points. - manifold->localNormal = localNormal; - manifold->localPoint = planePoint; - - int32 pointCount = 0; - for (int32 i = 0; i < b2_maxManifoldPoints; ++i) - { - float32 separation = b2Dot(normal, clipPoints2[i].v) - frontOffset; - - if (separation <= totalRadius) - { - b2ManifoldPoint* cp = manifold->points + pointCount; - cp->localPoint = b2MulT(xf2, clipPoints2[i].v); - cp->id = clipPoints2[i].id; - if (flip) - { - // Swap features - b2ContactFeature cf = cp->id.cf; - cp->id.cf.indexA = cf.indexB; - cp->id.cf.indexB = cf.indexA; - cp->id.cf.typeA = cf.typeB; - cp->id.cf.typeB = cf.typeA; - } - ++pointCount; - } - } - - manifold->pointCount = pointCount; -} |