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-rw-r--r--3rdparty/bgfx/examples/common/bounds.cpp291
1 files changed, 291 insertions, 0 deletions
diff --git a/3rdparty/bgfx/examples/common/bounds.cpp b/3rdparty/bgfx/examples/common/bounds.cpp
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index 00000000000..4af4555511d
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+++ b/3rdparty/bgfx/examples/common/bounds.cpp
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+/*
+ * Copyright 2011-2015 Branimir Karadzic. All rights reserved.
+ * License: http://www.opensource.org/licenses/BSD-2-Clause
+ */
+
+#include <bx/rng.h>
+#include <bx/fpumath.h>
+#include "bounds.h"
+
+void aabbToObb(Obb& _obb, const Aabb& _aabb)
+{
+ memset(_obb.m_mtx, 0, sizeof(_obb.m_mtx) );
+ _obb.m_mtx[ 0] = (_aabb.m_max[0] - _aabb.m_min[0]) * 0.5f;
+ _obb.m_mtx[ 5] = (_aabb.m_max[1] - _aabb.m_min[1]) * 0.5f;
+ _obb.m_mtx[10] = (_aabb.m_max[2] - _aabb.m_min[2]) * 0.5f;
+ _obb.m_mtx[12] = (_aabb.m_min[0] + _aabb.m_max[0]) * 0.5f;
+ _obb.m_mtx[13] = (_aabb.m_min[1] + _aabb.m_max[1]) * 0.5f;
+ _obb.m_mtx[14] = (_aabb.m_min[2] + _aabb.m_max[2]) * 0.5f;
+ _obb.m_mtx[15] = 1.0f;
+}
+
+void sphereToAabb(Aabb& _aabb, const Sphere& _sphere)
+{
+ float xx = _sphere.m_center[0];
+ float yy = _sphere.m_center[1];
+ float zz = _sphere.m_center[2];
+ float radius = _sphere.m_radius;
+ _aabb.m_min[0] = xx - radius;
+ _aabb.m_min[1] = yy - radius;
+ _aabb.m_min[2] = zz - radius;
+ _aabb.m_max[0] = xx + radius;
+ _aabb.m_max[1] = yy + radius;
+ _aabb.m_max[2] = zz + radius;
+}
+
+void aabbTransformToObb(Obb& _obb, const Aabb& _aabb, const float* _mtx)
+{
+ aabbToObb(_obb, _aabb);
+ float result[16];
+ bx::mtxMul(result, _obb.m_mtx, _mtx);
+ memcpy(_obb.m_mtx, result, sizeof(result) );
+}
+
+float calcAreaAabb(Aabb& _aabb)
+{
+ float ww = _aabb.m_max[0] - _aabb.m_min[0];
+ float hh = _aabb.m_max[1] - _aabb.m_min[1];
+ float dd = _aabb.m_max[2] - _aabb.m_min[2];
+ return 2.0f * (ww*hh + ww*dd + hh*dd);
+}
+
+void calcAabb(Aabb& _aabb, const void* _vertices, uint32_t _numVertices, uint32_t _stride)
+{
+ float min[3], max[3];
+ uint8_t* vertex = (uint8_t*)_vertices;
+ float* position = (float*)vertex;
+ min[0] = max[0] = position[0];
+ min[1] = max[1] = position[1];
+ min[2] = max[2] = position[2];
+ vertex += _stride;
+
+ for (uint32_t ii = 1; ii < _numVertices; ++ii)
+ {
+ position = (float*)vertex;
+ vertex += _stride;
+
+ float xx = position[0];
+ float yy = position[1];
+ float zz = position[2];
+ min[0] = bx::fmin(xx, min[0]);
+ min[1] = bx::fmin(yy, min[1]);
+ min[2] = bx::fmin(zz, min[2]);
+ max[0] = bx::fmax(xx, max[0]);
+ max[1] = bx::fmax(yy, max[1]);
+ max[2] = bx::fmax(zz, max[2]);
+ }
+
+ _aabb.m_min[0] = min[0];
+ _aabb.m_min[1] = min[1];
+ _aabb.m_min[2] = min[2];
+ _aabb.m_max[0] = max[0];
+ _aabb.m_max[1] = max[1];
+ _aabb.m_max[2] = max[2];
+}
+
+void calcAabb(Aabb& _aabb, const float* _mtx, const void* _vertices, uint32_t _numVertices, uint32_t _stride)
+{
+ float min[3], max[3];
+ uint8_t* vertex = (uint8_t*)_vertices;
+
+ float position[3];
+ bx::vec3MulMtx(position, (float*)vertex, _mtx);
+ min[0] = max[0] = position[0];
+ min[1] = max[1] = position[1];
+ min[2] = max[2] = position[2];
+ vertex += _stride;
+
+ for (uint32_t ii = 1; ii < _numVertices; ++ii)
+ {
+ bx::vec3MulMtx(position, (float*)vertex, _mtx);
+ vertex += _stride;
+
+ float xx = position[0];
+ float yy = position[1];
+ float zz = position[2];
+ min[0] = bx::fmin(xx, min[0]);
+ min[1] = bx::fmin(yy, min[1]);
+ min[2] = bx::fmin(zz, min[2]);
+ max[0] = bx::fmax(xx, max[0]);
+ max[1] = bx::fmax(yy, max[1]);
+ max[2] = bx::fmax(zz, max[2]);
+ }
+
+ _aabb.m_min[0] = min[0];
+ _aabb.m_min[1] = min[1];
+ _aabb.m_min[2] = min[2];
+ _aabb.m_max[0] = max[0];
+ _aabb.m_max[1] = max[1];
+ _aabb.m_max[2] = max[2];
+}
+
+void aabbExpand(Aabb& _aabb, float _factor)
+{
+ _aabb.m_min[0] -= _factor;
+ _aabb.m_min[1] -= _factor;
+ _aabb.m_min[2] -= _factor;
+ _aabb.m_max[0] += _factor;
+ _aabb.m_max[1] += _factor;
+ _aabb.m_max[2] += _factor;
+}
+
+uint32_t aabbOverlapTest(Aabb& _aabb0, Aabb& _aabb1)
+{
+ const uint32_t ltMinX = _aabb0.m_max[0] < _aabb1.m_min[0];
+ const uint32_t gtMaxX = _aabb0.m_min[0] > _aabb1.m_max[0];
+ const uint32_t ltMinY = _aabb0.m_max[1] < _aabb1.m_min[1];
+ const uint32_t gtMaxY = _aabb0.m_min[1] > _aabb1.m_max[1];
+ const uint32_t ltMinZ = _aabb0.m_max[2] < _aabb1.m_min[2];
+ const uint32_t gtMaxZ = _aabb0.m_min[2] > _aabb1.m_max[2];
+
+ return 0
+ | (ltMinX<<0)
+ | (gtMaxX<<1)
+ | (ltMinY<<2)
+ | (gtMaxY<<3)
+ | (ltMinZ<<4)
+ | (gtMaxZ<<5)
+ ;
+}
+
+void calcObb(Obb& _obb, const void* _vertices, uint32_t _numVertices, uint32_t _stride, uint32_t _steps)
+{
+ Aabb aabb;
+ calcAabb(aabb, _vertices, _numVertices, _stride);
+ float minArea = calcAreaAabb(aabb);
+
+ Obb best;
+ aabbToObb(best, aabb);
+
+ float angleStep = float(bx::piHalf/_steps);
+ float ax = 0.0f;
+ float mtx[16];
+
+ for (uint32_t ii = 0; ii < _steps; ++ii)
+ {
+ float ay = 0.0f;
+
+ for (uint32_t jj = 0; jj < _steps; ++jj)
+ {
+ float az = 0.0f;
+
+ for (uint32_t kk = 0; kk < _steps; ++kk)
+ {
+ bx::mtxRotateXYZ(mtx, ax, ay, az);
+
+ float mtxT[16];
+ bx::mtxTranspose(mtxT, mtx);
+ calcAabb(aabb, mtxT, _vertices, _numVertices, _stride);
+
+ float area = calcAreaAabb(aabb);
+ if (area < minArea)
+ {
+ minArea = area;
+ aabbTransformToObb(best, aabb, mtx);
+ }
+
+ az += angleStep;
+ }
+
+ ay += angleStep;
+ }
+
+ ax += angleStep;
+ }
+
+ memcpy(&_obb, &best, sizeof(Obb) );
+}
+
+void calcMaxBoundingSphere(Sphere& _sphere, const void* _vertices, uint32_t _numVertices, uint32_t _stride)
+{
+ Aabb aabb;
+ calcAabb(aabb, _vertices, _numVertices, _stride);
+
+ float center[3];
+ center[0] = (aabb.m_min[0] + aabb.m_max[0]) * 0.5f;
+ center[1] = (aabb.m_min[1] + aabb.m_max[1]) * 0.5f;
+ center[2] = (aabb.m_min[2] + aabb.m_max[2]) * 0.5f;
+
+ float maxDistSq = 0.0f;
+ uint8_t* vertex = (uint8_t*)_vertices;
+
+ for (uint32_t ii = 0; ii < _numVertices; ++ii)
+ {
+ float* position = (float*)vertex;
+ vertex += _stride;
+
+ float xx = position[0] - center[0];
+ float yy = position[1] - center[1];
+ float zz = position[2] - center[2];
+
+ float distSq = xx*xx + yy*yy + zz*zz;
+ maxDistSq = bx::fmax(distSq, maxDistSq);
+ }
+
+ _sphere.m_center[0] = center[0];
+ _sphere.m_center[1] = center[1];
+ _sphere.m_center[2] = center[2];
+ _sphere.m_radius = sqrtf(maxDistSq);
+}
+
+void calcMinBoundingSphere(Sphere& _sphere, const void* _vertices, uint32_t _numVertices, uint32_t _stride, float _step)
+{
+ bx::RngMwc rng;
+
+ uint8_t* vertex = (uint8_t*)_vertices;
+
+ float center[3];
+ float* position = (float*)&vertex[0];
+ center[0] = position[0];
+ center[1] = position[1];
+ center[2] = position[2];
+
+ position = (float*)&vertex[1*_stride];
+ center[0] += position[0];
+ center[1] += position[1];
+ center[2] += position[2];
+
+ center[0] *= 0.5f;
+ center[1] *= 0.5f;
+ center[2] *= 0.5f;
+
+ float xx = position[0] - center[0];
+ float yy = position[1] - center[1];
+ float zz = position[2] - center[2];
+ float maxDistSq = xx*xx + yy*yy + zz*zz;
+
+ float radiusStep = _step * 0.37f;
+
+ bool done;
+ do
+ {
+ done = true;
+ for (uint32_t ii = 0, index = rng.gen()%_numVertices; ii < _numVertices; ++ii, index = (index + 1)%_numVertices)
+ {
+ position = (float*)&vertex[index*_stride];
+
+ float xx = position[0] - center[0];
+ float yy = position[1] - center[1];
+ float zz = position[2] - center[2];
+ float distSq = xx*xx + yy*yy + zz*zz;
+
+ if (distSq > maxDistSq)
+ {
+ done = false;
+
+ center[0] += xx * radiusStep;
+ center[1] += yy * radiusStep;
+ center[2] += zz * radiusStep;
+ maxDistSq = bx::flerp(maxDistSq, distSq, _step);
+
+ break;
+ }
+ }
+
+ } while (!done);
+
+ _sphere.m_center[0] = center[0];
+ _sphere.m_center[1] = center[1];
+ _sphere.m_center[2] = center[2];
+ _sphere.m_radius = sqrtf(maxDistSq);
+}