From 31c33b9ed44b351127b7b4da317dc5ab69670b6f Mon Sep 17 00:00:00 2001 From: Gael Guennebaud Date: Sun, 7 Sep 2008 23:15:11 +0000 Subject: started a small OpenGL demo making use of Eigen's geometry features --- demos/opengl/gpuhelper.cpp | 211 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 211 insertions(+) create mode 100644 demos/opengl/gpuhelper.cpp (limited to 'demos/opengl/gpuhelper.cpp') diff --git a/demos/opengl/gpuhelper.cpp b/demos/opengl/gpuhelper.cpp new file mode 100644 index 000000000..71348737c --- /dev/null +++ b/demos/opengl/gpuhelper.cpp @@ -0,0 +1,211 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. Eigen itself is part of the KDE project. +// +// Copyright (C) 2008 Gael Guennebaud +// +// Eigen is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 3 of the License, or (at your option) any later version. +// +// Alternatively, you can redistribute it and/or +// modify it under the terms of the GNU General Public License as +// published by the Free Software Foundation; either version 2 of +// the License, or (at your option) any later version. +// +// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public +// License and a copy of the GNU General Public License along with +// Eigen. If not, see . + +#include "gpuhelper.h" +#include +// PLEASE don't look at this old code... ;) + +#include +#include + +GpuHelper gpu; + +//-------------------------------------------------------------------------------- +// icosahedron +//-------------------------------------------------------------------------------- +#define X .525731112119133606 +#define Z .850650808352039932 + +static GLfloat vdata[12][3] = { + {-X, 0.0, Z}, {X, 0.0, Z}, {-X, 0.0, -Z}, {X, 0.0, -Z}, + {0.0, Z, X}, {0.0, Z, -X}, {0.0, -Z, X}, {0.0, -Z, -X}, + {Z, X, 0.0}, {-Z, X, 0.0}, {Z, -X, 0.0}, {-Z, -X, 0.0} +}; + +static GLint tindices[20][3] = { + {0,4,1}, {0,9,4}, {9,5,4}, {4,5,8}, {4,8,1}, + {8,10,1}, {8,3,10}, {5,3,8}, {5,2,3}, {2,7,3}, + {7,10,3}, {7,6,10}, {7,11,6}, {11,0,6}, {0,1,6}, + {6,1,10}, {9,0,11}, {9,11,2}, {9,2,5}, {7,2,11} }; +//-------------------------------------------------------------------------------- + + +GpuHelper::GpuHelper() +{ + mVpWidth = mVpHeight = 0; + mCurrentMatrixTarget = 0; + mInitialized = false; +} + +GpuHelper::~GpuHelper() +{ +} + +void GpuHelper::pushProjectionMode2D(ProjectionMode2D pm) +{ + // switch to 2D projection + pushMatrix(Matrix4f::Identity(),GL_PROJECTION); + + if(pm==PM_Normalized) + { + //glOrtho(-1., 1., -1., 1., 0., 1.); + } + else if(pm==PM_Viewport) + { + GLint vp[4]; + glGetIntegerv(GL_VIEWPORT, vp); + glOrtho(0., vp[2], 0., vp[3], -1., 1.); + } + + pushMatrix(Matrix4f::Identity(),GL_MODELVIEW); +} + +void GpuHelper::popProjectionMode2D(void) +{ + popMatrix(GL_PROJECTION); + popMatrix(GL_MODELVIEW); +} + +void GpuHelper::drawVector(const Vector3f& position, const Vector3f& vec, const Color& color, float aspect /* = 50.*/) +{ + static GLUquadricObj *cylindre = gluNewQuadric(); + glColor4fv(color.data()); + float length = vec.norm(); + pushMatrix(GL_MODELVIEW); + glTranslatef(position.x(), position.y(), position.z()); + Vector3f ax = Matrix3f::Identity().col(2).cross(vec); + ax.normalize(); + Vector3f tmp = vec; + tmp.normalize(); + float angle = 180.f/M_PI * acos(tmp.z()); + if (angle>1e-3) + glRotatef(angle, ax.x(), ax.y(), ax.z()); + gluCylinder(cylindre, length/aspect, length/aspect, 0.8*length, 10, 10); + glTranslatef(0.0,0.0,0.8*length); + gluCylinder(cylindre, 2.0*length/aspect, 0.0, 0.2*length, 10, 10); + + popMatrix(GL_MODELVIEW); +} + +void GpuHelper::drawVectorBox(const Vector3f& position, const Vector3f& vec, const Color& color, float aspect) +{ + static GLUquadricObj *cylindre = gluNewQuadric(); + glColor4fv(color.data()); + float length = vec.norm(); + pushMatrix(GL_MODELVIEW); + glTranslatef(position.x(), position.y(), position.z()); + Vector3f ax = Matrix3f::Identity().col(2).cross(vec); + ax.normalize(); + Vector3f tmp = vec; + tmp.normalize(); + float angle = 180.f/M_PI * acos(tmp.z()); + if (angle>1e-3) + glRotatef(angle, ax.x(), ax.y(), ax.z()); + gluCylinder(cylindre, length/aspect, length/aspect, 0.8*length, 10, 10); + glTranslatef(0.0,0.0,0.8*length); + glScalef(4.0*length/aspect,4.0*length/aspect,4.0*length/aspect); + drawUnitCube(); + popMatrix(GL_MODELVIEW); +} + +void GpuHelper::drawUnitCube(void) +{ + static float vertices[][3] = { + {-0.5,-0.5,-0.5}, + { 0.5,-0.5,-0.5}, + {-0.5, 0.5,-0.5}, + { 0.5, 0.5,-0.5}, + {-0.5,-0.5, 0.5}, + { 0.5,-0.5, 0.5}, + {-0.5, 0.5, 0.5}, + { 0.5, 0.5, 0.5}}; + + glBegin(GL_QUADS); + glNormal3f(0,0,-1); glVertex3fv(vertices[0]); glVertex3fv(vertices[2]); glVertex3fv(vertices[3]); glVertex3fv(vertices[1]); + glNormal3f(0,0, 1); glVertex3fv(vertices[4]); glVertex3fv(vertices[5]); glVertex3fv(vertices[7]); glVertex3fv(vertices[6]); + glNormal3f(0,-1,0); glVertex3fv(vertices[0]); glVertex3fv(vertices[1]); glVertex3fv(vertices[5]); glVertex3fv(vertices[4]); + glNormal3f(0, 1,0); glVertex3fv(vertices[2]); glVertex3fv(vertices[6]); glVertex3fv(vertices[7]); glVertex3fv(vertices[3]); + glNormal3f(-1,0,0); glVertex3fv(vertices[0]); glVertex3fv(vertices[4]); glVertex3fv(vertices[6]); glVertex3fv(vertices[2]); + glNormal3f( 1,0,0); glVertex3fv(vertices[1]); glVertex3fv(vertices[3]); glVertex3fv(vertices[7]); glVertex3fv(vertices[5]); + glEnd(); +} + +void _normalize(float* v) +{ + float s = 1.f/ei_sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]); + for (uint k=0; k<3; ++k) + v[k] *= s; +} + +void _subdivide(float *v1, float *v2, float *v3, long depth) +{ + GLfloat v12[3], v23[3], v31[3]; + GLint i; + + if (depth == 0) { + //drawtriangle(v1, v2, v3); + glNormal3fv(v1); + glVertex3fv(v1); + + glNormal3fv(v3); + glVertex3fv(v3); + + glNormal3fv(v2); + glVertex3fv(v2); + + return; + } + for (i = 0; i < 3; i++) { + v12[i] = v1[i]+v2[i]; + v23[i] = v2[i]+v3[i]; + v31[i] = v3[i]+v1[i]; + } + _normalize(v12); + _normalize(v23); + _normalize(v31); + _subdivide(v1, v12, v31, depth-1); + _subdivide(v2, v23, v12, depth-1); + _subdivide(v3, v31, v23, depth-1); + _subdivide(v12, v23, v31, depth-1); +} + +void GpuHelper::drawUnitLightSphere(int level) +{ + static int dlId = 0; + if (!dlId) + { + dlId = glGenLists(1); + glNewList(dlId, GL_COMPILE); + glBegin(GL_TRIANGLES); + for (int i = 0; i < 20; i++) + { + _subdivide(&vdata[tindices[i][0]][0], &vdata[tindices[i][1]][0], &vdata[tindices[i][2]][0], 1); + } + glEnd(); + glEndList(); + } + glCallList(dlId); +} + + -- cgit v1.2.3