From 4ec7db55c227d3c38f2358fa74ff2649d6583391 Mon Sep 17 00:00:00 2001
From: Philipp Sehmisch <tmw@crushnet.org>
Date: Mon, 23 Jun 2008 14:44:20 +0000
Subject: Implemented "alpha" particle property.

---
 src/imageparticle.cpp   | 2 +-
 src/particle.cpp        | 1 +
 src/particle.h          | 8 ++++++++
 src/particleemitter.cpp | 7 +++++++
 src/particleemitter.h   | 8 +++++---
 src/textparticle.cpp    | 4 ++--
 6 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/imageparticle.cpp b/src/imageparticle.cpp
index 17581a2a..965434b0 100644
--- a/src/imageparticle.cpp
+++ b/src/imageparticle.cpp
@@ -56,7 +56,7 @@ void ImageParticle::draw(Graphics *graphics, int offsetX, int offsetY) const
         return;
     }
 
-    float alphafactor = 1.0f;
+    float alphafactor = mAlpha;
 
     if (mLifetimeLeft > -1 && mLifetimeLeft < mFadeOut)
         alphafactor *= (float) mLifetimeLeft / (float) mFadeOut;
diff --git a/src/particle.cpp b/src/particle.cpp
index ac40fe1a..fd45430c 100644
--- a/src/particle.cpp
+++ b/src/particle.cpp
@@ -57,6 +57,7 @@ Particle::Particle(Map *map):
     mLifetimePast(0),
     mFadeOut(0),
     mFadeIn(0),
+    mAlpha(1.0f),
     mAutoDelete(true),
     mMap(map),
     mGravity(0.0f),
diff --git a/src/particle.h b/src/particle.h
index 045ab9b9..5ba2668b 100644
--- a/src/particle.h
+++ b/src/particle.h
@@ -183,6 +183,13 @@ class Particle : public Sprite
         setFadeIn(int fadeIn)
         { mFadeIn = fadeIn; }
 
+        /**
+         * Sets the alpha value of the particle
+         */
+        void
+        setAlpha(float alpha)
+        { mAlpha = alpha; }
+
         /**
          * Sets the sprite iterator of the particle on the current map to make
          * it easier to remove the particle from the map when it is destroyed.
@@ -265,6 +272,7 @@ class Particle : public Sprite
         int mLifetimePast;          /**< Age of the particle in game ticks*/
         int mFadeOut;               /**< Lifetime in game ticks left where fading out begins*/
         int mFadeIn;                /**< Age in game ticks where fading in is finished*/
+        float mAlpha;               /**< Opacity of the graphical representation of the particle */
 
     private:
         // generic properties
diff --git a/src/particleemitter.cpp b/src/particleemitter.cpp
index 6f66b632..8f46c32b 100644
--- a/src/particleemitter.cpp
+++ b/src/particleemitter.cpp
@@ -61,6 +61,7 @@ ParticleEmitter::ParticleEmitter(xmlNodePtr emitterNode, Particle *target, Map *
     mParticleFadeOut.set(0);
     mParticleFadeIn.set(0);
     mOutput.set(1);
+    mParticleAlpha.set(1.0f);
 
     for_each_xml_child_node(propertyNode, emitterNode)
     {
@@ -153,6 +154,10 @@ ParticleEmitter::ParticleEmitter(xmlNodePtr emitterNode, Particle *target, Map *
             {
                 mParticleFadeIn = readMinMax(propertyNode, 0);
             }
+            else if (name == "alpha")
+            {
+                mParticleAlpha = readMinMax(propertyNode, 1.0f);
+            }
             else
             {
                 logger->log("Particle Engine: Warning, unknown emitter property \"%s\"",
@@ -260,6 +265,7 @@ ParticleEmitter & ParticleEmitter::operator=(const ParticleEmitter &o)
     mParticleLifetime = o.mParticleLifetime;
     mParticleFadeOut = o.mParticleFadeOut;
     mParticleFadeIn = o.mParticleFadeIn;
+    mParticleAlpha = o.mParticleAlpha;
     mMap = o.mMap;
     mOutput = o.mOutput;
     mParticleImage = o.mParticleImage;
@@ -343,6 +349,7 @@ ParticleEmitter::createParticles()
         newParticle->setLifetime(mParticleLifetime.value());
         newParticle->setFadeOut(mParticleFadeOut.value());
         newParticle->setFadeIn(mParticleFadeIn.value());
+        newParticle->setAlpha(mParticleAlpha.value());
 
         for (std::list<ParticleEmitter>::iterator i = mParticleChildEmitters.begin();
              i != mParticleChildEmitters.end();
diff --git a/src/particleemitter.h b/src/particleemitter.h
index c9524488..b7331527 100644
--- a/src/particleemitter.h
+++ b/src/particleemitter.h
@@ -119,10 +119,12 @@ class ParticleEmitter
 
         MinMax<int> mOutput;   /**< Number of particles spawned per update */
 
+        /*
+         * Graphical representation of the particle
+         */
         Image *mParticleImage; /**< Particle image, if used */
-
-        /** Filename of particle animation file */
-        Animation mParticleAnimation;
+        Animation mParticleAnimation; /**< Filename of particle animation file */
+        MinMax<float> mParticleAlpha; /**< Opacity of the graphical representation of the particles */
 
         /** List of emitters the spawned particles are equipped with */
         std::list<ParticleEmitter> mParticleChildEmitters;
diff --git a/src/textparticle.cpp b/src/textparticle.cpp
index 4bc859cd..89466006 100644
--- a/src/textparticle.cpp
+++ b/src/textparticle.cpp
@@ -45,7 +45,7 @@ void TextParticle::draw(Graphics *graphics, int offsetX, int offsetY) const
     int screenX = (int) mPos.x + offsetX;
     int screenY = (int) mPos.y - (int) mPos.z + offsetY;
 
-    int alpha = 255;
+    float alpha = mAlpha * 255.0f;
 
     if (mLifetimeLeft > -1 && mLifetimeLeft < mFadeOut)
     {
@@ -60,6 +60,6 @@ void TextParticle::draw(Graphics *graphics, int offsetX, int offsetY) const
     }
 
     graphics->setFont(mTextFont);
-    graphics->setColor(gcn::Color(mColorR, mColorG, mColorB, alpha));
+    graphics->setColor(gcn::Color(mColorR, mColorG, mColorB, (int)alpha));
     graphics->drawText(mText, screenX, screenY, gcn::Graphics::CENTER);
 }
-- 
cgit v1.2.3-70-g09d2