finally fixed the particle system.

data/shader/particle.frag

@@ -1,16 +1,27 @@
 #version 120
 varying vec2 vertex;
 varying vec2 velocity;
-uniform float maxAge;
+varying float decay;
-uniform float time;
+
+vec3 hsv2rgb(vec3 c)
+{
+    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
 void main()
 {
-  //gl_FragColor = vec4(0.5+0.5*vertex.x, 0.5+0.5*vertex.y, 0.0, 1.0);
+    gl_FragColor = vec4(0.5+0.5*vertex.x, 0.5+0.5*vertex.y, 0.0, 1.0);
-  if (length(vertex) > 1.0) {
+    float r = length(vertex);
-    discard;
+    if (r > 1.0) {
+        discard;
     }
-  float decay = time / maxAge;
+    float d = decay;
-  decay = 5.0*decay*decay;
+    float h = (1.0-d)/6.0;
-  // (length(10.0*velocity));
+    float v = max(0.0, (1.0-d/2.0) - 0.1*(d*d*d));
-  gl_FragColor = vec4(1.0/max(1.0, decay), 1.0/max(1.0, 6.0*decay), 0.0, 1.0);
+    float s = 1.0;
+    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

@@ -2,17 +2,25 @@
 attribute vec2 in_vertex;
 attribute vec2 in_position;
 attribute vec2 in_velocity;
+
+uniform float maxAge;
+varying float decay;
 varying vec2 velocity;
 varying vec2 vertex;
 uniform float time;
 uniform float size;
 void main()
 {
-  vec2 p = size*in_vertex;
+  //decay = min(1.0, time+5.0*length(velocity)) / maxAge;
+  //decay = max(decay*decay, sqrt(decay));
+  decay = time / maxAge;
+
+  vec2 base = in_vertex;
+  vec2 p = size*base;
   p += log(1.0+time) * in_velocity;
   p += in_position;
   gl_Position = vec4(p, 0.0, 1.0);
 
-  vertex = in_vertex;
+  vertex   = base;
   velocity = in_velocity;
 }

game/renderer_polygon_3d/particle_batch.cpp

@@ -6,12 +6,14 @@
 
 int getDivisorForIndex(int index)
 {
-    return (index == 0) ? 1 : 4;
+    // 0 or 1?
+    return (index == 0) ? 0 : 3;
 }
 
 namespace endofthejedi {
-    ParticleBatch::ParticleBatch(size_t numParticles, float particleSize, float maxAge)
+    ParticleBatch::ParticleBatch(size_t id, size_t numParticles, float particleSize, float maxAge)
-        : m_numParticles(numParticles)
+        : m_id(id)
+        , m_numParticles(numParticles)
         , m_particleRadius(particleSize)
         , m_maxAge(maxAge)
         , m_age(0.0)
@@ -36,11 +38,27 @@ namespace endofthejedi {
         m_shader.init();
         m_shader.loadFile(vss_particles, GL_VERTEX_SHADER);
         m_shader.loadFile(fss_particles, GL_FRAGMENT_SHADER);
+
+        const char *names[] = {
+            "in_vertex",
+            "in_position",
+            "in_velocity",
+            "XXXunusedXXX",
+            "XXXunusedXXX"
+        };
+
+        for (int i=0; i<5; i++) {
+            const char *name = names[i];
+            GLint loc = glGetAttribLocation(m_shader.program(), name);
+            m_attr_locations[i] = loc;
+            //std::cout<<"attr location " << i << " " << loc << " " << name << std::endl;
+        }
     }
 
     ParticleBatch::~ParticleBatch()
     {
         // TODO: find out if stuff must be deallocated
+        glDeleteBuffers(5, m_data_vbos);
     }
 
     void ParticleBatch::setParticle(size_t index, const glm::vec2 &p, const glm::vec2 &v)
@@ -63,16 +81,14 @@ namespace endofthejedi {
 
         for (size_t i=0; i<5; i++) {
             //std::cout<<"vbo #" << i << ": " << m_data_vbos[i] << std::endl;
-            glEnableVertexAttribArray(i);
+            glEnableVertexAttribArray(m_attr_locations[i]);
             glBindBuffer(GL_ARRAY_BUFFER, m_data_vbos[i]);
 
-            if (i != 0) {
+            glVertexAttribDivisor(m_attr_locations[i], getDivisorForIndex(i));
-                glVertexAttribDivisor(i, getDivisorForIndex(i-1));
-            }
 
             // TODO: i or index? at first argument?
             glVertexAttribPointer(
-                    i,
+                    m_attr_locations[i],
                     dataSizeForIndex(i),
                     GL_FLOAT,  // Data is floating point type
                     GL_FALSE,  // No fixed point scaling
@@ -85,9 +101,9 @@ namespace endofthejedi {
     {
         //std::cout<<"[ParticleBatch] upload to vbo's " << std::endl;
 
-        glGenBuffers(4, m_data_vbos);            // Generate buffer
+        glGenBuffers(5, m_data_vbos);            // Generate buffer
 
-        for (size_t i=0; i<4; i++) {
+        for (size_t i=0; i<5; i++) {
             size_t bufferDataSize = dataSizeForIndex(i) * m_numParticles * sizeof(float);
 
             glEnableVertexAttribArray(i);
@@ -105,14 +121,8 @@ namespace endofthejedi {
     void ParticleBatch::render()
     {
         //std::cout<<"[ParticleBatch] render " << std::endl;
-
         m_shader.bind();
 
-        // TODO: does that work?
-        glBindAttribLocation(m_shader.program(), 0, "in_vertex");
-        glBindAttribLocation(m_shader.program(), 1, "in_position");
-        glBindAttribLocation(m_shader.program(), 2, "in_velocity");
-
         glUniform1f(m_shader.location("time"),   m_age);
         glUniform1f(m_shader.location("maxAge"), m_maxAge);
         glUniform1f(m_shader.location("size"),   m_particleRadius);
@@ -122,7 +132,10 @@ namespace endofthejedi {
         //glDrawArrays(GL_TRIANGLE_FAN, 0, 4*m_numParticles);
 
         //glDrawArraysInstanced( GLenum mode, GLint first, GLsizei count, GLsizei primcount);
-        glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, 4*m_numParticles);
+        // XXX the 3 is a magical number.
+        // I dont know why this works
+        // without it, it will render 1/3 of the particles
+        glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, 3*m_numParticles);
 
 #if 0
         glBegin(GL_QUADS);

game/renderer_polygon_3d/particle_batch.hpp

@@ -9,7 +9,7 @@
 namespace endofthejedi {
     class ParticleBatch {
         public:
-            ParticleBatch(size_t numParticles, float particleRadius, float maxAge);
+            ParticleBatch(size_t id, size_t numParticles, float particleRadius, float maxAge);
 
             // deallocate opengl stuff on destroy
             ~ParticleBatch();
@@ -27,11 +27,14 @@ namespace endofthejedi {
 
             Shader *shader() { return &m_shader; }
 
+            size_t id() const { return m_id; }
+
         private:
             size_t dataSizeForIndex(int i);
             void  *dataSourceForIndex(int i);
 
         private:
+            size_t                 m_id;
             size_t                 m_numParticles;
             float                  m_particleRadius;
             const float            m_maxAge;
@@ -45,6 +48,8 @@ namespace endofthejedi {
             std::vector<float>     m_data_kind;
             std::vector<float>     m_data_max_age;
 
+            GLuint                 m_attr_locations[5];
+
             Shader                 m_shader;
     };
 }

game/renderer_polygon_3d/polygon_model.cpp

@@ -72,6 +72,7 @@ namespace endofthejedi {
             glEnableVertexAttribArray(m_attr_locations[0]);
             glBindBuffer(GL_ARRAY_BUFFER, m_vbo_id[i]);
             glVertexAttribPointer(m_attr_locations[i], 3, GL_FLOAT, GL_FALSE, 0, NULL);
+            glVertexAttribDivisor(m_attr_locations[i], 0); // restore default
         }
 
         m_binding_active = true;
@@ -149,10 +150,6 @@ namespace endofthejedi {
             return false;
         }
 
-        /************************************************************/
-        /* Position data */
-        /************************************************************/
-
         glGenBuffers(2, m_vbo_id);            // Generate buffer
 
         glEnableVertexAttribArray(m_attr_locations[0]);

game/renderer_polygon_3d/renderer_polygon_3d.cpp

@@ -28,7 +28,7 @@ namespace endofthejedi {
 #endif
 
         addModel("../data/mesh/small_atomic_bomb.stl", &m_missileModel);
-        addModel("../data/mesh/planet_64.stl",         &m_planetModel);
+        addModel("../data/mesh/planet_12.stl",         &m_planetModel);
         addModel("../data/mesh/ship_ufo.stl",          &m_shipModel);
     }
 
@@ -65,9 +65,7 @@ namespace endofthejedi {
         renderShips();
         renderMissiles();
 
-        //glDisable(GL_DEPTH_TEST);
+        renderParticles();
-        //renderParticles();
-        //glEnable(GL_DEPTH_TEST);
 
         renderTraces();
 
@@ -90,18 +88,21 @@ namespace endofthejedi {
         }
     }
 
-    void RendererPolygon3d::addExplosionEffect(const glm::vec2 &pos, size_t n, float duration)
+    void RendererPolygon3d::addExplosionEffect(size_t id, const glm::vec2 &pos, size_t n, float duration)
     {
-        ParticleBatch *batch = new ParticleBatch(n, 0.005, duration);
+        //float particleRadius = 0.005;
+        float particleRadius = 0.005;
+
+        ParticleBatch *batch = new ParticleBatch(id, n, particleRadius, duration);
 
         for (size_t i=0; i<n; i++) {
             // distribute in a circle
-            float t = 4.0 * M_PI * i / (float) n;
+            float t = 2.0 * M_PI * i / (float) n;
-            t += 0.2*util::randf_m1_1();
+            //t += 0.2*util::randf_m1_1();
 
             // with random velocities
-            glm::vec2 v = 0.2f*glm::vec2(sin(t), cos(t));
+            glm::vec2 v = 0.5f*glm::vec2(sin(t), cos(t));
-            v *= 0.2+0.8*util::randf_0_1();
+            v *= util::randf_0_1() + util::randf_0_1();
 
             batch->setParticle(i, pos, v);
         }
@@ -114,11 +115,23 @@ namespace endofthejedi {
     void RendererPolygon3d::advanceGraphicObjects(float dt)
     {
         for (const game::Explosion *expl : m_state->explosions) {
-            if (expl->age == 0.0) {
+            bool gotIt = false;
-                addExplosionEffect(expl->position, 200, 3.0);
+            for (ParticleBatch *batch : m_particles) {
+                if (batch->id() == expl->id) {
+                    gotIt = true;
+                    break;
+                }
+            }
+
+            if (!gotIt) {
+                addExplosionEffect(expl->id, expl->position, 1000, 2.0);
             }
         }
 
+        //if (m_particles.size() == 0) {
+        //    addExplosionEffect(0, glm::vec2(0.0, 0.0), 1000, 2.0);
+        //}
+
         std::vector<ParticleBatch*> rm;
 
         for (ParticleBatch *batch : m_particles) {
@@ -246,7 +259,8 @@ namespace endofthejedi {
         // revert to default
         glUseProgram(0);
 
-        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+        // TODO dont use line mode. make that with own quads
+        glPolygonMode(GL_FRONT, GL_LINE);
         for (const game::Trace *trace : m_state->traces) {
             float fade_out = 1.0;
             if (trace->missile == nullptr) {
@@ -260,5 +274,6 @@ namespace endofthejedi {
             }
             glEnd();
         }
+        glPolygonMode(GL_FRONT, GL_FILL);
     }
 }

game/renderer_polygon_3d/renderer_polygon_3d.hpp

@@ -34,7 +34,7 @@ namespace endofthejedi {
 
             void addModel(const std::string &filename, PolygonModel **dest);
 
-            void addExplosionEffect(const glm::vec2 &pos, size_t n, float duration);
+            void addExplosionEffect(size_t id, const glm::vec2 &pos, size_t n, float duration);
 
             void advanceGraphicObjects(float dt);
 

game/state/explosion.hpp

@@ -19,6 +19,8 @@ namespace game {
             , maxAge(maxAge * (1.0 + 0.1*util::randf_0_1()))
             , maxRadius(0.05)
         {
+            static size_t id_counter = 0;
+            id = id_counter++;
         }
 
         const Hit       hit;      // kind of the explosion depends on the hit type
@@ -29,5 +31,7 @@ namespace game {
         // anymore and will disappear afterwards
         const float     maxAge;
         const float     maxRadius; // current radius depends on time.
+
+        size_t          id;
     };
 }