--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/modules/graphics/opengl/ParticleSystem.cpp	Sun Jul 26 15:46:49 2009 +0200
@@ -0,0 +1,497 @@
+/**
+* Copyright (c) 2006-2009 LOVE Development Team
+* 
+* This software is provided 'as-is', without any express or implied
+* warranty.  In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* 
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 
+* 1. The origin of this software must not be misrepresented; you must not
+*    claim that you wrote the original software. If you use this software
+*    in a product, an acknowledgment in the product documentation would be
+*    appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+*    misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+**/
+
+#include "ParticleSystem.h"
+
+#include <SDL_opengl.h>
+#include <cmath>
+#include <cstdlib>
+
+namespace love
+{
+namespace graphics
+{
+namespace opengl
+{
+
+	float calculate_variation(float inner, float outer, float var)
+	{
+		float low = inner - (outer/2.0f)*var;
+		float high = inner + (outer/2.0f)*var;
+		float r = (rand() / (float(RAND_MAX)+1));
+		return low*(1-r)+high*r;
+	}
+
+
+	ParticleSystem::ParticleSystem(Image * sprite, unsigned int buffer) : pStart(0), pLast(0), pEnd(0), active(true), emissionRate(0),
+															emitCounter(0), lifetime(-1), life(0), particleLifeMin(0), particleLifeMax(0),
+															direction(0), spread(0), relative(false), speedMin(0), speedMax(0), gravityMin(0),
+															gravityMax(0), radialAccelerationMin(0), radialAccelerationMax(0),
+															tangentialAccelerationMin(0), tangentialAccelerationMax(0),
+															sizeStart(1), sizeEnd(1), sizeVariation(0), rotationMin(0), rotationMax(0),
+															spinStart(0), spinEnd(0), spinVariation(0)
+	{	
+		this->sprite = sprite;
+		sprite->retain();
+		colorStart = Color(255, 255, 255, 255);
+		colorEnd = Color(255, 255, 255, 255);
+		setBufferSize(buffer);
+	}
+
+	ParticleSystem::~ParticleSystem()
+	{
+		if(this->sprite != 0)
+		{
+			this->sprite->release();
+			this->sprite = 0;
+		}
+
+		if(pStart != 0)
+			delete [] pStart;
+	}
+
+	void ParticleSystem::add()
+	{
+		if(isFull()) return;
+		
+		float min,max;
+
+		min = particleLifeMin;
+		max = particleLifeMax;
+		if(min == max)
+			pLast->life = min;
+		else
+			pLast->life = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;
+		pLast->lifetime = pLast->life;
+
+		pLast->position[0] = position.getX();
+		pLast->position[1] = position.getY();
+
+		min = direction - spread/2.0f;
+		max = direction + spread/2.0f;
+		pLast->direction = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;
+
+		min = speedMin;
+		max = speedMax;
+		float speed = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;
+		pLast->speed = love::Vector(cos(pLast->direction), sin(pLast->direction));
+		pLast->speed *= speed;
+
+		min = gravityMin;
+		max = gravityMax;
+		pLast->gravity = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;
+
+		min = radialAccelerationMin;
+		max = radialAccelerationMax;
+		pLast->radialAcceleration = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;
+
+		min = tangentialAccelerationMin;
+		max = tangentialAccelerationMax;
+		pLast->tangentialAcceleration = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;
+
+		pLast->sizeStart = calculate_variation(sizeStart, sizeEnd, sizeVariation);
+		pLast->sizeEnd = calculate_variation(sizeEnd, sizeStart, sizeVariation);
+		pLast->size = pLast->sizeStart;
+
+		min = rotationMin;
+		max = rotationMax;
+		pLast->spinStart = calculate_variation(spinStart, spinEnd, spinVariation);
+		pLast->spinEnd = calculate_variation(spinEnd, spinStart, spinVariation);
+		pLast->rotation = (rand() / (float(RAND_MAX)+1)) * (max - min) + min;;
+
+		pLast->color[0] = (float)colorStart.getRed() / 255;
+		pLast->color[1] = (float)colorStart.getGreen() / 255;
+		pLast->color[2] = (float)colorStart.getBlue() / 255;
+		pLast->color[3] = (float)colorStart.getAlpha() / 255;
+			
+		pLast++;
+	}
+
+	void ParticleSystem::remove(particle * p)
+	{
+		if(!isEmpty())
+		{
+			*p = *(--pLast);
+		}
+	}
+
+	void ParticleSystem::setSprite(Image * image)
+	{
+		if(this->sprite != 0)
+		{
+			this->sprite->release();
+			this->sprite = 0;
+		}
+
+		this->sprite = image;
+	}
+
+	void ParticleSystem::setBufferSize(unsigned int size)
+	{
+		// delete previous data
+		delete [] pStart;
+
+		pLast = pStart = new particle[size];
+
+		pEnd = pStart + size;
+	}
+
+	void ParticleSystem::setEmissionRate(int rate)
+	{
+		emissionRate = rate;
+	}
+
+	void ParticleSystem::setLifetime(float life)
+	{
+		this->life = lifetime = life;
+	}
+
+	void ParticleSystem::setParticleLife(float min, float max)
+	{
+		particleLifeMin = min;
+		if(max == 0)
+			particleLifeMax = min;
+		else
+			particleLifeMax = max;
+	}
+
+	void ParticleSystem::setPosition(float x, float y)
+	{
+		position = love::Vector(x, y);
+	}
+
+	void ParticleSystem::setDirection(float direction)
+	{
+		this->direction = direction * LOVE_M_TORAD;
+	}
+
+	void ParticleSystem::setSpread(float spread)
+	{
+		this->spread = spread * LOVE_M_TORAD;
+	}
+
+	void ParticleSystem::setRelativeDirection(bool relative)
+	{
+		this->relative = relative;
+	}
+
+	void ParticleSystem::setSpeed(float speed)
+	{
+		speedMin = speedMax = speed;
+	}
+
+	void ParticleSystem::setSpeed(float min, float max)
+	{
+		speedMin = min;
+		speedMax = max;
+	}
+
+	void ParticleSystem::setGravity(float gravity)
+	{
+		gravityMin = gravityMax = gravity;
+	}
+
+	void ParticleSystem::setGravity(float min, float max)
+	{
+		gravityMin = min;
+		gravityMax = max;
+	}
+
+	void ParticleSystem::setRadialAcceleration(float acceleration)
+	{
+		radialAccelerationMin = radialAccelerationMax = acceleration;
+	}
+
+	void ParticleSystem::setRadialAcceleration(float min, float max)
+	{
+		radialAccelerationMin = min;
+		radialAccelerationMax = max;
+	}
+
+	void ParticleSystem::setTangentialAcceleration(float acceleration)
+	{
+		tangentialAccelerationMin = tangentialAccelerationMax = acceleration;
+	}
+
+	void ParticleSystem::setTangentialAcceleration(float min, float max)
+	{
+		tangentialAccelerationMin = min;
+		tangentialAccelerationMax = max;
+	}
+
+	void ParticleSystem::setSize(float size)
+	{
+		sizeStart = size;
+		sizeEnd = size;
+	}
+
+	void ParticleSystem::setSize(float start, float end)
+	{
+		sizeStart = start;
+		sizeEnd = end;
+	}
+
+	void ParticleSystem::setSize(float start, float end, float variation)
+	{
+		sizeStart = start;
+		sizeEnd = end;
+		sizeVariation = variation;
+	}
+
+	void ParticleSystem::setSizeVariation(float variation)
+	{
+		sizeVariation = variation;
+	}
+
+	void ParticleSystem::setRotation(float rotation)
+	{
+		rotationMin = rotationMax = rotation;
+	}
+
+	void ParticleSystem::setRotation(float min, float max)
+	{
+		rotationMin = min;
+		rotationMax = max;
+	}
+
+	void ParticleSystem::setSpin(float spin)
+	{
+		spinStart = spin * LOVE_M_TORAD;
+		spinEnd = spin * LOVE_M_TORAD;
+	}
+
+	void ParticleSystem::setSpin(float start, float end)
+	{
+		spinStart = start * LOVE_M_TORAD;
+		spinEnd = end * LOVE_M_TORAD;
+	}
+
+	void ParticleSystem::setSpin(float start, float end, float variation)
+	{
+		spinStart = start * LOVE_M_TORAD;
+		spinEnd = end * LOVE_M_TORAD;
+		spinVariation = variation * LOVE_M_TORAD;
+	}
+
+	void ParticleSystem::setSpinVariation(float variation)
+	{
+		spinVariation = variation * LOVE_M_TORAD;
+	}
+
+	void ParticleSystem::setColor(Color * color)
+	{
+		colorStart = *color;
+		colorEnd = *color;
+	}
+
+	void ParticleSystem::setColor(Color * start, Color * end)
+	{
+		colorStart = *start;
+		colorEnd = *end;
+	}
+
+	float ParticleSystem::getX() const
+	{
+		return position.getX();
+	}
+
+	float ParticleSystem::getY() const
+	{
+		return position.getY();
+	}
+
+	float ParticleSystem::getDirection() const
+	{
+		return direction * LOVE_M_TODEG;
+	}
+
+	float ParticleSystem::getSpread() const
+	{
+		return spread * LOVE_M_TODEG;
+	}
+
+	int ParticleSystem::count() const
+	{
+		return (int)(pLast - pStart);
+	}
+
+	void ParticleSystem::start()
+	{
+		active = true;
+	}
+
+	void ParticleSystem::stop()
+	{
+		active = false;
+		life = lifetime;
+		emitCounter = 0;
+	}
+
+	void ParticleSystem::pause()
+	{
+		active = false;
+	}
+
+	void ParticleSystem::reset()
+	{
+		pLast = pStart;
+		life = lifetime;
+		emitCounter = 0;
+	}
+
+	bool ParticleSystem::isActive() const
+	{
+		return active;
+	}
+
+	bool ParticleSystem::isEmpty() const
+	{
+		return pStart == pLast;
+	}
+
+	bool ParticleSystem::isFull() const
+	{
+		return pLast == pEnd;
+	}
+
+	void ParticleSystem::draw(float x, float y, float angle, float sx, float sy, float ox, float oy) const
+	{
+		if(sprite == 0) return; // just in case of failure
+
+		glPushMatrix();
+		glPushAttrib(GL_CURRENT_BIT);
+
+		glTranslatef(x, y, 0);
+		glRotatef(angle, 0, 0, 1.0f);
+		glScalef(sx, sy, 1.0f);
+		glTranslatef( ox, oy, 0);
+
+		particle * p = pStart;
+		while(p != pLast)
+		{
+			glPushMatrix();
+
+			glColor4f(p->color[0],p->color[1],p->color[2],p->color[3]);
+			glTranslatef(p->position[0],p->position[1],0.0f);
+			glRotatef(p->rotation * 57.29578f, 0.0f, 0.0f, 1.0f); // rad * (180 / pi)
+			glScalef(p->size,p->size,1.0f);
+			sprite->draw(0,0, 0, 1, 1, 0, 0);
+
+			glPopMatrix();
+			p++;
+		}
+
+		glPopAttrib();
+		glPopMatrix();
+	}
+
+	void ParticleSystem::update(float dt)
+	{
+		// Traverse all particles and update.
+		particle * p = pStart;
+
+		// Make some more particles.
+		if(active)
+		{
+			float rate = 1.0f / emissionRate; // the amount of time between each particle emit
+			emitCounter += dt;
+			while(emitCounter > rate)
+			{
+				add();
+				emitCounter -= rate;
+			}
+			/*int particles = (int)(emissionRate * dt);
+			for(int i = 0; i != particles; i++)
+				add();*/
+
+			life -= dt;
+			if(lifetime != -1 && life < 0)
+				stop();
+		}
+
+		while(p != pLast)
+		{
+			// Decrease lifespan.
+			p->life -= dt;
+
+			if(p->life > 0)
+			{
+
+				// Temp variables.
+				love::Vector radial, tangential, gravity(0, p->gravity);
+				love::Vector ppos(p->position[0], p->position[1]);
+
+				// Get vector from particle center to particle.
+				radial = ppos - position;
+				radial.normalize();
+				tangential = radial;
+
+				// Resize radial acceleration.
+				radial *= p->radialAcceleration;
+
+				// Calculate tangential acceleration.
+				{
+					float a = tangential.getX();
+					tangential.setX(-tangential.getY());
+					tangential.setY(a);
+				}
+
+				// Resize tangential.
+				tangential *= p->tangentialAcceleration;
+
+				// Update position.
+				p->speed += (radial+tangential+gravity)*dt;
+
+				// Modify position.
+				ppos += p->speed * dt;
+
+				p->position[0] = ppos.getX();
+				p->position[1] = ppos.getY();
+
+				const float t = p->life / p->lifetime;
+
+				// Change size.
+				p->size = p->sizeEnd - ((p->sizeEnd - p->sizeStart) * t);
+
+				// Rotate.
+				p->rotation += (p->spinStart*(1-t) + p->spinEnd*t)*dt;
+
+				// Update color.
+				p->color[0] = (float)(colorEnd.getRed()*(1.0f-t) + colorStart.getRed() * t)/255.0f;
+				p->color[1] = (float)(colorEnd.getGreen()*(1.0f-t) + colorStart.getGreen() * t)/255.0f;
+				p->color[2] = (float)(colorEnd.getBlue()*(1.0f-t) + colorStart.getBlue() * t)/255.0f;
+				p->color[3] = (float)(colorEnd.getAlpha()*(1.0f-t) + colorStart.getAlpha() * t)/255.0f;
+	
+				// Next particle.
+				p++;
+			}
+			else
+			{
+				remove(p);
+
+				if(p >= pLast)
+					return;
+			} // else
+		} // while
+	}
+
+} // opengl
+} // graphics
+} // love