From a9609ed770925c3d459e3a2c0b1d45b973721a21 Mon Sep 17 00:00:00 2001
From: Niklas Birk <nikla.birk.nb@gmail.com>
Date: Sat, 28 Dec 2019 13:54:53 +0100
Subject: [PATCH] several things

---
 main.c           | 30 ++++++++++++++++++------------
 particlesystem.c | 20 +++++++++++++-------
 particlesystem.h |  4 +++-
 3 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/main.c b/main.c
index 7a6550b..b717672 100644
--- a/main.c
+++ b/main.c
@@ -31,44 +31,49 @@ int main()
     glfwMakeContextCurrent(window);
 
     vector3f *epos = initVector3f(0, 0, 0);
-    emitter *e = initEmitter(epos, 1000);
+    emitter *e = initEmitter(epos, 10000);
     particle_system *ps = initParticleSystem(1);
     (ps->emitters)[0] = e;
 
     initRandomParticles(e);
 
+    double time, tFrame, tLast = 0;
+    int width, height, b = 0;
+
     while (!glfwWindowShouldClose(window))
     {
-        int width, height;
+        time = glfwGetTime();
+        tFrame = time - tLast;
+        tLast = time;
 
         glfwGetFramebufferSize(window, &width, &height);
 
-        int b = 0;
-        for (int i = 0; i < e->pamount; i++)
+        for (int i = 0; !b && i < e->pamount; i++)
         {
             vector3f *p = (e->particles)[i]->position;
             if (p->x > 1 || p->x < -1 || p->y > 1 || p->y < -1 || p->z > 1 || p->z < -1)
             {
                 b=1;
-                break;
             }
         }
 
         if (!b)
         {
-            updateParticles(4000, ps);
+            updateParticles((float) tFrame, ps);
         }
 
         glViewport(0, 0, width, height);
         glClear(GL_COLOR_BUFFER_BIT);
 
         glBegin(GL_POINTS);
+        particle *p;
+        vector3f *pos;
         for (int i = 0; i < e->pamount; i++)
         {
-
-            glColor3f((float) rand() / RAND_MAX, (float) rand() / RAND_MAX, (float) rand() / RAND_MAX);
-            vector3f *p = (e->particles)[i]->position;
-            glVertex3f(p->x, p->y, p->z);
+            p = (e->particles)[i];
+            glColor3f(p->color->x, p->color->y, p->color->z);
+            pos = p->position;
+            glVertex3f(pos->x, pos->y, pos->z);
         }
         glEnd();
 
@@ -81,7 +86,7 @@ int main()
     glfwTerminate();
 
     free(epos);
-    freeEmitter(e);
+    freeParticleSystem(ps);
 
     return 0;
 }
@@ -105,7 +110,8 @@ void initRandomParticles(emitter *e)
     {
         vector3f *pos = initVector3f(e->position->x, e->position->y, e->position->z);
         vector3f *dir = initVector3f(rv(), rv(), rv());
-        (e->particles)[i] = initParticle(pos, dir);
+        vector3f *color = initVector3f(255, 255, 255);
+        (e->particles)[i] = initParticle(pos, dir, color, 100.f);
     }
 }
 
diff --git a/particlesystem.c b/particlesystem.c
index c28ce2d..408165f 100644
--- a/particlesystem.c
+++ b/particlesystem.c
@@ -6,11 +6,13 @@
 /*
  * Initializes a particle
  */
-particle *initParticle(vector3f *pos, vector3f *dir)
+particle *initParticle(vector3f *pos, vector3f *dir, vector3f *color, float age)
 {
     particle *p = malloc(sizeof(particle));
     p->position = pos;
     p->direction = dir;
+    p->color = color;
+    p->age = age;
     return p;
 }
 
@@ -43,17 +45,21 @@ particle_system *initParticleSystem(int eamount)
 int updateParticles(float dt, particle_system *ps)
 {
     emitter *e;
-    float t = 1 / dt;
+    particle *p;
     for (int i = 0; i < ps->eamount; i++)
     {
         e = (ps->emitters)[i];
         for (int j = 0; j < e->pamount; j++)
         {
-            vector3f *p = (e->particles)[j]->position;
-            vector3f *d = (e->particles)[j]->direction;
-            p->x += d->x * t;
-            p->y += d->y * t;
-            p->z += d->z * t;
+            p = (e->particles)[j];
+
+            p->position->x += p->direction->x * dt;
+            p->position->y += p->direction->y * dt;
+            p->position->z += p->direction->z * dt;
+
+            p->color->x -= 0.25f;
+            p->color->y -= 0.25f;
+            p->color->z -= 0.25f;
         }
     }
 }
diff --git a/particlesystem.h b/particlesystem.h
index dbf6806..910208c 100644
--- a/particlesystem.h
+++ b/particlesystem.h
@@ -15,6 +15,8 @@ typedef struct particle
 {
     vector3f *position;
     vector3f *direction;
+    vector3f *color;
+    float age;
 } particle;
 
 /*
@@ -39,7 +41,7 @@ typedef struct particle_system
 /*
  * Initializes a particle
  */
-particle *initParticle(vector3f *pos, vector3f *dir);
+particle *initParticle(vector3f *pos, vector3f *dir, vector3f *color, float age);
 
 /*
  * Initializes an emitter