very nice particles with heat in the center of the explosion and moving in 3d space.

data/shader/particle.frag

@@ -1,8 +1,11 @@
 #version 120
-varying vec2 vertex;
+varying vec2  vertex;
-varying vec2 velocity;
+varying vec3  velocity;
 varying float decay;
 
+varying float explCenterDist;
+uniform vec3  explCenter;
+
 vec3 hsv2rgb(vec3 c)
 {
     vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
@@ -17,10 +20,16 @@ void main()
     if (r > 1.0) {
         discard;
     }
-    float d = decay;
+
+    float d = decay/(1.0+max(0.0, 1.0-explCenterDist));
     float h = (1.0-d)/6.0;
-    float v = max(0.0, (1.0-d/2.0) - 0.1*(d*d*d));
+    float v = max(0.0, (1.0-log(d)));
     float s = 1.0;
+
+    //v /= decay * 10.0*length(vertex-explCenter);
+    //v /= 1.0+2.0*length(vertex-explCenter);
+    v /= 1.0 + max(0.0, min(35.0*(decay-0.2), 1.0)) * 15.0 * explCenterDist;
+
     gl_FragColor = vec4(hsv2rgb(vec3(h, s, v)), 1.0);
 
     //gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);

data/shader/particle.vert

@@ -1,26 +1,37 @@
 #version 120
 attribute vec2 in_vertex;
-attribute vec2 in_position;
+attribute vec3 in_position;
-attribute vec2 in_velocity;
+attribute vec3 in_velocity;
 
-uniform float maxAge;
+uniform float age;
-varying float decay;
-varying vec2 velocity;
-varying vec2 vertex;
-uniform float time;
 uniform float size;
+uniform float maxVelocity;
+uniform float maxAge;
+uniform vec3  explCenter;
+
+varying float decay;
+varying vec3  velocity;
+varying vec2  vertex;
+varying float explCenterDist;
+
+// TODO: rotate to face the user!
 void main()
 {
-  //decay = min(1.0, time+5.0*length(velocity)) / maxAge;
+  //decay = min(1.0, age+5.0*length(velocity)) / maxAge;
   //decay = max(decay*decay, sqrt(decay));
-  decay = time / maxAge;
+  decay = age / maxAge;
 
+  // faster particles are smaller
+  float s = size * (1.0-length(in_velocity)/maxVelocity);
   vec2 base = in_vertex;
-  vec2 p = size*base;
+  vec3 p = s*vec3(base, 0.0);
-  p += log(1.0+time) * in_velocity;
+  vec3 offset = log(1.0+age) * in_velocity + in_position;
-  p += in_position;
+  p += offset;
-  gl_Position = vec4(p, 0.0, 1.0);
 
-  vertex   = base;
+  gl_Position = vec4(p, 1.0);
+
+  vertex   = base.xy;
   velocity = in_velocity;
+
+  explCenterDist = length(explCenter-offset);
 }

game/renderer_polygon_3d/particle_batch.cpp

@@ -17,6 +17,8 @@ namespace endofthejedi {
         , m_particleRadius(particleSize)
         , m_maxAge(maxAge)
         , m_age(0.0)
+        , m_maxVelocity(1.0)
+        , m_center(glm::vec3(0.0f, 0.0f, 0.0f))
 
         // 2d quad drawn as a triangle fan
         , m_data_quad({
@@ -61,7 +63,17 @@ namespace endofthejedi {
         glDeleteBuffers(5, m_data_vbos);
     }
 
-    void ParticleBatch::setParticle(size_t index, const glm::vec2 &p, const glm::vec2 &v)
+    void ParticleBatch::setCenter(const glm::vec3 &center)
+    {
+        m_center = center;
+    }
+
+    void ParticleBatch::setMaxVelocity(float maxVelocity)
+    {
+        m_maxVelocity = maxVelocity;
+    }
+
+    void ParticleBatch::setParticle(size_t index, const glm::vec3 &p, const glm::vec3 &v)
     {
         if (index >= m_numParticles) {
             return;
@@ -123,9 +135,11 @@ namespace endofthejedi {
         //std::cout<<"[ParticleBatch] render " << std::endl;
         m_shader.bind();
 
-        glUniform1f(m_shader.location("time"),   m_age);
+        glUniform1f(m_shader.location("age"),         m_age);
-        glUniform1f(m_shader.location("maxAge"), m_maxAge);
+        glUniform1f(m_shader.location("maxVelocity"), m_maxVelocity);
-        glUniform1f(m_shader.location("size"),   m_particleRadius);
+        glUniform1f(m_shader.location("maxAge"),      m_maxAge);
+        glUniform1f(m_shader.location("size"),        m_particleRadius);
+        glUniform3f(m_shader.location("center"),      m_center.x, m_center.y, m_center.z);
 
         bind();
 
@@ -155,9 +169,11 @@ namespace endofthejedi {
     {
         switch(i) {
             case 0:
+                return 2;
+
             case 1:
             case 2:
-                return 2;
+                return 3;
 
             case 3:
             case 4:

game/renderer_polygon_3d/particle_batch.hpp

@@ -3,6 +3,7 @@
 #include <vector>
 
 #include <glm/vec2.hpp>
+#include <glm/vec3.hpp>
 
 #include "glclasses.hpp"
 
@@ -16,7 +17,10 @@ namespace endofthejedi {
 
             size_t numParticles() const { return m_numParticles; }
 
-            void setParticle(size_t index, const glm::vec2 &p, const glm::vec2 &v);
+            void setParticle(size_t index, const glm::vec3 &p, const glm::vec3 &v);
+
+            void setCenter(const glm::vec3 &center);
+            void setMaxVelocity(float maxVelocity);
 
             void bind();
             void upload();
@@ -39,12 +43,14 @@ namespace endofthejedi {
             float                  m_particleRadius;
             const float            m_maxAge;
             float                  m_age;
+            float                  m_maxVelocity;
+            glm::vec3              m_center;
 
             GLuint                 m_data_vbos[5];
 
             std::vector<float>     m_data_quad;
-            std::vector<glm::vec2> m_data_position;
+            std::vector<glm::vec3> m_data_position;
-            std::vector<glm::vec2> m_data_velocity;
+            std::vector<glm::vec3> m_data_velocity;
             std::vector<float>     m_data_kind;
             std::vector<float>     m_data_max_age;
 

game/renderer_polygon_3d/renderer_polygon_3d.cpp

@@ -5,6 +5,7 @@
 #include <glm/gtc/type_ptr.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtx/euler_angles.hpp>
+#include <glm/gtc/random.hpp>
 
 namespace endofthejedi {
     void RendererPolygon3d::setup()
@@ -54,11 +55,13 @@ namespace endofthejedi {
 
         m_shader.bind();
 
-        glm::vec3 c = glm::vec3(1.0, 1.0, 0.5);
+        // TODO: add ONE sun planet
+        // TODO: add lights for explosions
+
+        glm::vec3 c = glm::vec3(1.0, 1.0, 0.8);
         glUniform3f(m_shader.location("lightColor"), c.x, c.y, c.z);
 
-        //glm::vec3 p = glm::vec3(1.0, 0.0, 0.0);
+		glm::vec3 p = glm::vec3(0.3f, 0.4f, 0.0f);
-		glm::vec3 p = glm::vec3(0.5f, 0.5f, -4.0f);
         glUniform3f(m_shader.location("lightPosition"), p.x, p.y, p.z);
 
         renderPlanets();
@@ -91,20 +94,34 @@ namespace endofthejedi {
     void RendererPolygon3d::addExplosionEffect(size_t id, const glm::vec2 &pos, size_t n, float duration)
     {
         //float particleRadius = 0.005;
-        float particleRadius = 0.005;
+        //float particleRadius = 0.003;
+        float particleRadius = 0.01;
+
+        // TODO: use this as shader input too and make the area 2x around this
+        // so that it stays hot/yellow for 2/3 of the time
+        float explSize = 0.01f;
+
+        float maxVelocity = 0.2f;
 
         ParticleBatch *batch = new ParticleBatch(id, n, particleRadius, duration);
+        batch->setCenter(glm::vec3(pos, 0.0));
+        batch->setMaxVelocity(maxVelocity);
 
         for (size_t i=0; i<n; i++) {
             // distribute in a circle
-            float t = 2.0 * M_PI * i / (float) n;
+            //float t = 2.0 * M_PI * i / (float) n;
             //t += 0.2*util::randf_m1_1();
 
             // with random velocities
-            glm::vec2 v = 0.5f*glm::vec2(sin(t), cos(t));
+            // this is 3d because it looks better if some particles leave/enter
+            // the space and they are not all on one plane.
+            // especially in 3d this would look bad without 3d velocity vector.
+            //glm::vec3 v = 0.5f*glm::vec3(sin(t), cos(t), util::randf_m1_1());
+
+            glm::vec3 v = glm::ballRand(maxVelocity);
             v *= util::randf_0_1() + util::randf_0_1();
 
-            batch->setParticle(i, pos, v);
+            batch->setParticle(i, glm::vec3(pos, 0.0) + glm::ballRand(explSize), v);
         }
 
         batch->upload();
@@ -124,13 +141,13 @@ namespace endofthejedi {
             }
 
             if (!gotIt) {
-                addExplosionEffect(expl->id, expl->position, 1000, 2.0);
+                addExplosionEffect(expl->id, expl->position, 500, 5.0);
             }
         }
 
-        //if (m_particles.size() == 0) {
+        if (m_particles.size() == 0) {
-        //    addExplosionEffect(0, glm::vec2(0.0, 0.0), 1000, 2.0);
+            addExplosionEffect(0, glm::vec2(0.0, 0.0), 1000, 5.0);
-        //}
+        }
 
         std::vector<ParticleBatch*> rm;
 

game/renderer_polygon_3d/renderer_polygon_3d.hpp

@@ -17,6 +17,7 @@
 #include "particle_batch.hpp"
 #include "polygon_model.hpp"
 
+#include <glm/vec3.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 
 namespace endofthejedi {