Checked in osgParticle, writtten by Marco Jez.

src/osgParticle/Particle.cpp

@@ -0,0 +1,146 @@
+#include <osgParticle/Particle>
+#include <osgParticle/LinearInterpolator>
+
+#include <osg/Vec3>
+#include <osg/Vec4>
+#include <osg/Matrix>
+#include <osg/GL>
+#include <osg/Notify>
+
+namespace
+{
+
+    const float cosPI3 = cosf(osg::PI / 3.0f);
+    const float sinPI3 = sinf(osg::PI / 3.0f);
+    const float hex_texcoord_x1 = 0.5f + 0.5f * cosPI3;
+    const float hex_texcoord_x2 = 0.5f - 0.5f * cosPI3;
+    const float hex_texcoord_y1 = 0.5f + 0.5f * sinPI3;
+    const float hex_texcoord_y2 = 0.5f - 0.5f * sinPI3;
+
+}
+
+osgParticle::Particle::Particle()
+:    shape_(QUAD),
+    sr_(0.2f, 0.2f),
+    ar_(1, 0),
+    cr_(osg::Vec4(1, 1, 1, 1), osg::Vec4(1, 1, 1, 1)),
+    si_(osgNew LinearInterpolator), 
+    ai_(osgNew LinearInterpolator), 
+    ci_(osgNew LinearInterpolator),
+    alive_(true),
+    mustdie_(false),
+    lifetime_(2),
+    radius_(0.2f),
+    mass_(0.1f),
+    massinv_(10.0f),
+    prev_pos_(0, 0, 0),
+    position_(0, 0, 0),
+    velocity_(0, 0, 0),
+    t0_(0)    
+{
+}
+
+bool osgParticle::Particle::update(double dt)
+{
+    // this method should return false when the particle dies;
+    // so, if we were instructed to die, do it now and return.
+    if (mustdie_) {
+        alive_ = false;
+        return false;
+    }
+
+    double x = 0;    
+
+    // if we don't live forever, compute our normalized age.
+    if (lifetime_ > 0) {
+        x = t0_ / lifetime_;
+    }
+
+    t0_ += dt;
+
+    // if our age is over the lifetime limit, then die and return.
+    if (x > 1) {
+        alive_ = false;
+        return false;
+    }
+
+    // compute the current values for size, alpha and color.
+    current_size_ = si_.get()->interpolate(x, sr_);
+    current_alpha_ = ai_.get()->interpolate(x, ar_);
+    current_color_ = ci_.get()->interpolate(x, cr_);
+
+    // update position
+    prev_pos_ = position_;
+    position_ += velocity_ * dt;
+
+    return true;
+}
+
+void osgParticle::Particle::render(const osg::Matrix &modelview, float scale) const
+{
+    osg::Vec3 xpos = modelview.preMult(position_);
+
+    glColor4f(    current_color_.x(), 
+                current_color_.y(), 
+                current_color_.z(), 
+                current_color_.w() * current_alpha_);
+
+    float cs = current_size_ * scale;
+
+    switch (shape_)
+    {
+    case POINT:        
+        glVertex3f(xpos.x(), xpos.y(), xpos.z());        
+        break;
+
+    case QUAD:
+        glTexCoord2f(0, 0);
+        glVertex3f(xpos.x() - cs, xpos.y() - cs, xpos.z());
+        glTexCoord2f(1, 0);
+        glVertex3f(xpos.x() + cs, xpos.y() - cs, xpos.z());
+        glTexCoord2f(1, 1);
+        glVertex3f(xpos.x() + cs, xpos.y() + cs, xpos.z());
+        glTexCoord2f(0, 1);
+        glVertex3f(xpos.x() - cs, xpos.y() + cs, xpos.z());
+        break;
+
+    case QUAD_TRIANGLESTRIP:
+        // we must glBegin() and glEnd() here, because each particle is a single strip
+        glBegin(GL_TRIANGLE_STRIP);
+        glTexCoord2f(1, 1);
+        glVertex3f(xpos.x() + cs, xpos.y() + cs, xpos.z());
+        glTexCoord2f(0, 1);
+        glVertex3f(xpos.x() - cs, xpos.y() + cs, xpos.z());
+        glTexCoord2f(1, 0);
+        glVertex3f(xpos.x() + cs, xpos.y() - cs, xpos.z());
+        glTexCoord2f(0, 0);
+        glVertex3f(xpos.x() - cs, xpos.y() - cs, xpos.z());
+        glEnd();
+        break;
+
+    case HEXAGON:
+        // we must glBegin() and glEnd() here, because each particle is a single fan
+        glBegin(GL_TRIANGLE_FAN);
+        glTexCoord2f(0.5f, 0.5f);
+        glVertex3f(xpos.x(), xpos.y(), xpos.z());
+        glTexCoord2f(hex_texcoord_x1, hex_texcoord_y1);
+        glVertex3f(xpos.x() + cs * cosPI3, xpos.y() + cs * sinPI3, xpos.z());
+        glTexCoord2f(hex_texcoord_x2, hex_texcoord_y1);
+        glVertex3f(xpos.x() - cs * cosPI3, xpos.y() + cs * sinPI3, xpos.z());
+        glTexCoord2f(0, 0.5f);
+        glVertex3f(xpos.x() - cs, xpos.y(), xpos.z());
+        glTexCoord2f(hex_texcoord_x2, hex_texcoord_y2);
+        glVertex3f(xpos.x() - cs * cosPI3, xpos.y() - cs * sinPI3, xpos.z());
+        glTexCoord2f(hex_texcoord_x1, hex_texcoord_y2);
+        glVertex3f(xpos.x() + cs * cosPI3, xpos.y() - cs * sinPI3, xpos.z());
+        glTexCoord2f(1, 0.5f);
+        glVertex3f(xpos.x() + cs, xpos.y(), xpos.z());
+        glTexCoord2f(hex_texcoord_x1, hex_texcoord_y1);
+        glVertex3f(xpos.x() + cs * cosPI3, xpos.y() + cs * sinPI3, xpos.z());
+        glEnd();
+        break;
+
+    default:
+        osg::notify(osg::WARN) << "Invalid shape for particles\n";
+    }
+}