mirror of https://github.com/axmolengine/axmol.git
482 lines
11 KiB
C++
482 lines
11 KiB
C++
/*
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* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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#ifndef RAY_CAST_H
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#define RAY_CAST_H
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// This test demonstrates how to use the world ray-cast feature.
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// NOTE: we are intentionally filtering one of the polygons, therefore
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// the ray will always miss one type of polygon.
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// This callback finds the closest hit. Polygon 0 is filtered.
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class RayCastClosestCallback : public b2RayCastCallback
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{
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public:
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RayCastClosestCallback()
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{
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m_hit = false;
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}
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float32 ReportFixture(b2Fixture* fixture, const b2Vec2& point, const b2Vec2& normal, float32 fraction)
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{
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b2Body* body = fixture->GetBody();
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void* userData = body->GetUserData();
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if (userData)
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{
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int32 index = *(int32*)userData;
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if (index == 0)
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{
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// By returning -1, we instruct the calling code to ignore this fixture and
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// continue the ray-cast to the next fixture.
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return -1.0f;
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}
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}
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m_hit = true;
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m_point = point;
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m_normal = normal;
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// By returning the current fraction, we instruct the calling code to clip the ray and
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// continue the ray-cast to the next fixture. WARNING: do not assume that fixtures
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// are reported in order. However, by clipping, we can always get the closest fixture.
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return fraction;
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}
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bool m_hit;
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b2Vec2 m_point;
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b2Vec2 m_normal;
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};
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// This callback finds any hit. Polygon 0 is filtered. For this type of query we are usually
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// just checking for obstruction, so the actual fixture and hit point are irrelevant.
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class RayCastAnyCallback : public b2RayCastCallback
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{
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public:
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RayCastAnyCallback()
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{
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m_hit = false;
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}
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float32 ReportFixture(b2Fixture* fixture, const b2Vec2& point, const b2Vec2& normal, float32 fraction)
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{
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b2Body* body = fixture->GetBody();
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void* userData = body->GetUserData();
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if (userData)
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{
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int32 index = *(int32*)userData;
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if (index == 0)
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{
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// By returning -1, we instruct the calling code to ignore this fixture
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// and continue the ray-cast to the next fixture.
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return -1.0f;
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}
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}
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m_hit = true;
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m_point = point;
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m_normal = normal;
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// At this point we have a hit, so we know the ray is obstructed.
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// By returning 0, we instruct the calling code to terminate the ray-cast.
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return 0.0f;
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}
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bool m_hit;
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b2Vec2 m_point;
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b2Vec2 m_normal;
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};
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// This ray cast collects multiple hits along the ray. Polygon 0 is filtered.
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// The fixtures are not necessary reported in order, so we might not capture
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// the closest fixture.
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class RayCastMultipleCallback : public b2RayCastCallback
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{
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public:
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enum
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{
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e_maxCount = 3
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};
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RayCastMultipleCallback()
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{
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m_count = 0;
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}
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float32 ReportFixture(b2Fixture* fixture, const b2Vec2& point, const b2Vec2& normal, float32 fraction)
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{
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b2Body* body = fixture->GetBody();
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void* userData = body->GetUserData();
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if (userData)
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{
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int32 index = *(int32*)userData;
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if (index == 0)
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{
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// By returning -1, we instruct the calling code to ignore this fixture
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// and continue the ray-cast to the next fixture.
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return -1.0f;
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}
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}
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b2Assert(m_count < e_maxCount);
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m_points[m_count] = point;
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m_normals[m_count] = normal;
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++m_count;
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if (m_count == e_maxCount)
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{
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// At this point the buffer is full.
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// By returning 0, we instruct the calling code to terminate the ray-cast.
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return 0.0f;
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}
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// By returning 1, we instruct the caller to continue without clipping the ray.
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return 1.0f;
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}
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b2Vec2 m_points[e_maxCount];
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b2Vec2 m_normals[e_maxCount];
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int32 m_count;
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};
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class RayCast : public Test
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{
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public:
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enum
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{
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e_maxBodies = 256
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};
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enum Mode
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{
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e_closest,
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e_any,
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e_multiple
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};
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RayCast()
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{
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// Ground body
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{
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b2BodyDef bd;
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b2Body* ground = m_world->CreateBody(&bd);
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b2EdgeShape shape;
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shape.Set(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));
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ground->CreateFixture(&shape, 0.0f);
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}
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{
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b2Vec2 vertices[3];
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vertices[0].Set(-0.5f, 0.0f);
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vertices[1].Set(0.5f, 0.0f);
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vertices[2].Set(0.0f, 1.5f);
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m_polygons[0].Set(vertices, 3);
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}
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{
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b2Vec2 vertices[3];
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vertices[0].Set(-0.1f, 0.0f);
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vertices[1].Set(0.1f, 0.0f);
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vertices[2].Set(0.0f, 1.5f);
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m_polygons[1].Set(vertices, 3);
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}
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{
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float32 w = 1.0f;
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float32 b = w / (2.0f + b2Sqrt(2.0f));
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float32 s = b2Sqrt(2.0f) * b;
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b2Vec2 vertices[8];
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vertices[0].Set(0.5f * s, 0.0f);
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vertices[1].Set(0.5f * w, b);
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vertices[2].Set(0.5f * w, b + s);
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vertices[3].Set(0.5f * s, w);
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vertices[4].Set(-0.5f * s, w);
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vertices[5].Set(-0.5f * w, b + s);
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vertices[6].Set(-0.5f * w, b);
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vertices[7].Set(-0.5f * s, 0.0f);
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m_polygons[2].Set(vertices, 8);
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}
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{
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m_polygons[3].SetAsBox(0.5f, 0.5f);
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}
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{
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m_circle.m_radius = 0.5f;
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}
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{
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m_edge.Set(b2Vec2(-1.0f, 0.0f), b2Vec2(1.0f, 0.0f));
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}
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m_bodyIndex = 0;
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memset(m_bodies, 0, sizeof(m_bodies));
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m_angle = 0.0f;
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m_mode = e_closest;
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}
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void Create(int32 index)
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{
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if (m_bodies[m_bodyIndex] != NULL)
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{
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m_world->DestroyBody(m_bodies[m_bodyIndex]);
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m_bodies[m_bodyIndex] = NULL;
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}
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b2BodyDef bd;
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float32 x = RandomFloat(-10.0f, 10.0f);
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float32 y = RandomFloat(0.0f, 20.0f);
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bd.position.Set(x, y);
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bd.angle = RandomFloat(-b2_pi, b2_pi);
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m_userData[m_bodyIndex] = index;
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bd.userData = m_userData + m_bodyIndex;
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if (index == 4)
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{
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bd.angularDamping = 0.02f;
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}
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m_bodies[m_bodyIndex] = m_world->CreateBody(&bd);
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if (index < 4)
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{
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b2FixtureDef fd;
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fd.shape = m_polygons + index;
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fd.friction = 0.3f;
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m_bodies[m_bodyIndex]->CreateFixture(&fd);
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}
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else if (index < 5)
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{
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b2FixtureDef fd;
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fd.shape = &m_circle;
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fd.friction = 0.3f;
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m_bodies[m_bodyIndex]->CreateFixture(&fd);
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}
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else
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{
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b2FixtureDef fd;
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fd.shape = &m_edge;
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fd.friction = 0.3f;
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m_bodies[m_bodyIndex]->CreateFixture(&fd);
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}
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m_bodyIndex = (m_bodyIndex + 1) % e_maxBodies;
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}
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void DestroyBody()
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{
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for (int32 i = 0; i < e_maxBodies; ++i)
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{
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if (m_bodies[i] != NULL)
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{
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m_world->DestroyBody(m_bodies[i]);
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m_bodies[i] = NULL;
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return;
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}
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}
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}
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void Keyboard(unsigned char key)
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{
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switch (key)
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{
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case '1':
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case '2':
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case '3':
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case '4':
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case '5':
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case '6':
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Create(key - '1');
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break;
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case 'd':
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DestroyBody();
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break;
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case 'm':
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if (m_mode == e_closest)
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{
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m_mode = e_any;
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}
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else if (m_mode == e_any)
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{
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m_mode = e_multiple;
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}
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else if (m_mode == e_multiple)
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{
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m_mode = e_closest;
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}
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}
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}
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void Step(Settings* settings)
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{
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bool advanceRay = settings->pause == 0 || settings->singleStep;
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Test::Step(settings);
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m_debugDraw.DrawString(5, m_textLine, "Press 1-6 to drop stuff, m to change the mode");
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m_textLine += DRAW_STRING_NEW_LINE;
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switch (m_mode)
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{
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case e_closest:
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m_debugDraw.DrawString(5, m_textLine, "Ray-cast mode: closest - find closest fixture along the ray");
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break;
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case e_any:
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m_debugDraw.DrawString(5, m_textLine, "Ray-cast mode: any - check for obstruction");
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break;
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case e_multiple:
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m_debugDraw.DrawString(5, m_textLine, "Ray-cast mode: multiple - gather multiple fixtures");
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break;
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}
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m_textLine += DRAW_STRING_NEW_LINE;
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float32 L = 11.0f;
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b2Vec2 point1(0.0f, 10.0f);
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b2Vec2 d(L * cosf(m_angle), L * sinf(m_angle));
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b2Vec2 point2 = point1 + d;
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if (m_mode == e_closest)
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{
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RayCastClosestCallback callback;
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m_world->RayCast(&callback, point1, point2);
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if (callback.m_hit)
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{
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m_debugDraw.DrawPoint(callback.m_point, 5.0f, b2Color(0.4f, 0.9f, 0.4f));
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m_debugDraw.DrawSegment(point1, callback.m_point, b2Color(0.8f, 0.8f, 0.8f));
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b2Vec2 head = callback.m_point + 0.5f * callback.m_normal;
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m_debugDraw.DrawSegment(callback.m_point, head, b2Color(0.9f, 0.9f, 0.4f));
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}
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else
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{
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m_debugDraw.DrawSegment(point1, point2, b2Color(0.8f, 0.8f, 0.8f));
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}
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}
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else if (m_mode == e_any)
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{
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RayCastAnyCallback callback;
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m_world->RayCast(&callback, point1, point2);
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if (callback.m_hit)
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{
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m_debugDraw.DrawPoint(callback.m_point, 5.0f, b2Color(0.4f, 0.9f, 0.4f));
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m_debugDraw.DrawSegment(point1, callback.m_point, b2Color(0.8f, 0.8f, 0.8f));
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b2Vec2 head = callback.m_point + 0.5f * callback.m_normal;
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m_debugDraw.DrawSegment(callback.m_point, head, b2Color(0.9f, 0.9f, 0.4f));
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}
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else
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{
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m_debugDraw.DrawSegment(point1, point2, b2Color(0.8f, 0.8f, 0.8f));
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}
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}
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else if (m_mode == e_multiple)
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{
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RayCastMultipleCallback callback;
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m_world->RayCast(&callback, point1, point2);
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m_debugDraw.DrawSegment(point1, point2, b2Color(0.8f, 0.8f, 0.8f));
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for (int32 i = 0; i < callback.m_count; ++i)
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{
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b2Vec2 p = callback.m_points[i];
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b2Vec2 n = callback.m_normals[i];
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m_debugDraw.DrawPoint(p, 5.0f, b2Color(0.4f, 0.9f, 0.4f));
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m_debugDraw.DrawSegment(point1, p, b2Color(0.8f, 0.8f, 0.8f));
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b2Vec2 head = p + 0.5f * n;
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m_debugDraw.DrawSegment(p, head, b2Color(0.9f, 0.9f, 0.4f));
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}
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}
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if (advanceRay)
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{
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m_angle += 0.25f * b2_pi / 180.0f;
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}
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#if 0
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// This case was failing.
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{
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b2Vec2 vertices[4];
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//vertices[0].Set(-22.875f, -3.0f);
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//vertices[1].Set(22.875f, -3.0f);
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//vertices[2].Set(22.875f, 3.0f);
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//vertices[3].Set(-22.875f, 3.0f);
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b2PolygonShape shape;
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//shape.Set(vertices, 4);
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shape.SetAsBox(22.875f, 3.0f);
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b2RayCastInput input;
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input.p1.Set(10.2725f,1.71372f);
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input.p2.Set(10.2353f,2.21807f);
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//input.maxFraction = 0.567623f;
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input.maxFraction = 0.56762173f;
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b2Transform xf;
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xf.SetIdentity();
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xf.position.Set(23.0f, 5.0f);
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b2RayCastOutput output;
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bool hit;
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hit = shape.RayCast(&output, input, xf);
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hit = false;
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b2Color color(1.0f, 1.0f, 1.0f);
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b2Vec2 vs[4];
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for (int32 i = 0; i < 4; ++i)
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{
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vs[i] = b2Mul(xf, shape.m_vertices[i]);
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}
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m_debugDraw.DrawPolygon(vs, 4, color);
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m_debugDraw.DrawSegment(input.p1, input.p2, color);
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}
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#endif
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}
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static Test* Create()
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{
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return new RayCast;
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}
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int32 m_bodyIndex;
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b2Body* m_bodies[e_maxBodies];
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int32 m_userData[e_maxBodies];
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b2PolygonShape m_polygons[4];
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b2CircleShape m_circle;
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b2EdgeShape m_edge;
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float32 m_angle;
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Mode m_mode;
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};
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#endif
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