From f1a648c038a2a6e1eb97e9f45a115fbe0da3df1f Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Fri, 18 Jul 2008 17:30:49 +0100
Subject: [PATCH] Nicer exhaust effect

---
 src/Emitter.cpp | 13 ++++++++-----
 src/Emitter.hpp |  4 +++-
 src/Ship.cpp    |  8 +++-----
 3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/Emitter.cpp b/src/Emitter.cpp
index e67e261..dd27bc0 100644
--- a/src/Emitter.cpp
+++ b/src/Emitter.cpp
@@ -40,7 +40,7 @@ Emitter::Emitter(int x, int y, float r, float g, float b, bool createnew,
                  float max_speed, float size, float slowdown)
   : partsize(size), r(r), g(g), b(b), deviation(deviation), xg(xg), yg(yg),
     life(life), maxspeed(max_speed), xpos((float)x), ypos((float)y),
-    slowdown(slowdown), createrate(64.0f)
+    slowdown(slowdown), createrate(128.0f), xi_bias(0.0f), yi_bias(0.0f)
 {
    LOAD_ONCE {
       texture = new Texture("images/particle.png");
@@ -188,6 +188,9 @@ void Emitter::NewParticle(int index)
       particle[index].xi = (float)((rand()%50)-26.0f)*maxspeed;
       particle[index].yi = (float)((rand()%50)-25.0f)*maxspeed;
    } while (pow(particle[index].yi, 2) + pow(particle[index].xi, 2) > pow(25.0f*maxspeed, 2));
+
+   particle[index].xi += xi_bias;
+   particle[index].yi += yi_bias;
 }
 
 
@@ -195,12 +198,12 @@ void Emitter::NewParticle(int index)
  * Smoke trail constructor. Sets special Emitter constants.
  */
 SmokeTrail::SmokeTrail()
-  : Emitter(0, 0, 0.9f, 0.9f, 0.0f,
+  : Emitter(0, 0, 0.9f, 0.7f, 0.0f,
             false, 0.2f,
-            0.0f, 0.1f,
-            0.3f, 20.0f, 4.0f, 2.0f)
+            0.0f, 0.0f,
+            0.3f, 0.0f, 5.0f, 0.001f)
 {
-	
+   createrate = 64.0f;
 }
 
 
diff --git a/src/Emitter.hpp b/src/Emitter.hpp
index e666f50..bde55b6 100644
--- a/src/Emitter.hpp
+++ b/src/Emitter.hpp
@@ -43,6 +43,8 @@ public:
    
    float partsize, r, g, b, deviation, xg, yg, life, maxspeed, flSize;
    float xpos, ypos, slowdown, createrate;
+
+   float xi_bias, yi_bias;
    
 protected:
    void NewParticle(int index);
@@ -55,7 +57,7 @@ protected:
       float xi, yi;
       float xg, yg;
    } particle[MAX_PARTICLES];
-
+   
    static Texture *texture;
 };
 
diff --git a/src/Ship.cpp b/src/Ship.cpp
index aae04cc..6895664 100644
--- a/src/Ship.cpp
+++ b/src/Ship.cpp
@@ -106,12 +106,10 @@ void Ship::Move()
        - (shipImage.GetWidth()/2)*(double)sin(angle*(PI/180));
     exhaust.ypos = ypos + shipImage.GetHeight()/2
        + (shipImage.GetHeight()/2)*(double)cos(angle*(PI/180));
-    //exhaust.yg = speedY; //+ (flGravity * 10);
-    //exhaust.xg = speedX;
 
-    const float SCALE = 10.0f;
-    exhaust.yg = SCALE * sin(angle);
-    exhaust.xg = SCALE * cos(angle);
+    const float SCALE = 1.0f;
+    exhaust.yi_bias = SCALE * cos(angle*PI/180) + speedY;
+    exhaust.xi_bias = SCALE * -sin(angle*PI/180) + speedX;
     
     explosion.xpos = xpos + shipImage.GetWidth()/2;
     explosion.ypos = ypos + shipImage.GetHeight()/2;
-- 
2.39.2