mostly implemented particle emitter

particleEmitter.cpp

@@ -0,0 +1,128 @@
+#include"particleEmitter.h"
+#include"shader.h"
+#include<algorithm>
+#include<glad.h>
+#include<glfw3.h>
+#include<cstdlib>
+#include<ext.hpp>
+#include"material.h"
+#include"node.h"
+#include"root.h"
+#include"camera.h"
+
+using namespace glm;
+using namespace std;
+
+namespace vb01{
+	ParticleEmitter::ParticleEmitter(int numParticles){
+		this->numParticles=numParticles;
+
+		particles=new Particle[numParticles];
+
+		Vertex v1,v2,v3,v4,v5,v6;
+		Vector2 size=Vector2(.5,.5);
+		v1.pos=Vector3(size.x/2,size.y/2,0);
+		v1.texCoords=Vector2(1,1);
+
+		v2.pos=Vector3(-size.x/2,size.y/2,0);
+		v2.texCoords=Vector2(0,1);
+
+		v3.pos=Vector3(-size.x/2,-size.y/2,0);
+		v3.texCoords=Vector2(0,0);
+
+		v4.pos=Vector3(-size.x/2,-size.y/2,0);
+		v4.texCoords=Vector2(0,0);
+
+		v5.pos=Vector3(size.x/2,-size.y/2,0);
+		v5.texCoords=Vector2(1,0);
+
+		v6.pos=Vector3(size.x/2,size.y/2,0);
+		v6.texCoords=Vector2(1,1);
+		
+		ParticleEmitter::Vertex vertices[]={v1,v2,v3,v4,v5,v6};
+		unsigned int indices[]={0,1,2,3,4,5};
+
+		for(int i=0;i<numParticles;i++){
+			mat4 mat=translate(mat4(1.f),vec3(0,0,0));
+			Particle p;
+			p.mat=mat;
+			p.dir=direction;
+			particles[i]=p;
+		}
+
+		glGenVertexArrays(1,&VAO);
+		glGenBuffers(1,&VBO);
+		glGenBuffers(1,&EBO);
+		glBindVertexArray(VAO);
+		glBindBuffer(GL_ARRAY_BUFFER,VBO);
+		glBufferData(GL_ARRAY_BUFFER,6*sizeof(Vertex),vertices,GL_STATIC_DRAW);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,EBO);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER,6*sizeof(unsigned int),indices,GL_STATIC_DRAW);
+		glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,sizeof(Vertex),(void*)0);
+		glEnableVertexAttribArray(0);
+		glVertexAttribPointer(1,2,GL_FLOAT,GL_FALSE,sizeof(Vertex),(void*)(offsetof(Vertex,texCoords)));
+		glEnableVertexAttribArray(1);
+
+		startColor=Vector4(1,0,0,1);
+		endColor=Vector4(0,0,1,1);
+		//endSize=Vector2(2,2);
+		direction=Vector3(0,.1,0);
+		spread=.3;
+	}
+
+	ParticleEmitter::~ParticleEmitter(){}
+
+	void ParticleEmitter::update(){
+		Root *root=Root::getSingleton();
+		Camera *cam=root->getCamera();
+		float fov=cam->getFov(),width=root->getWidth(),height=root->getHeight();
+		float nearPlane=cam->getNearPlane(),farPlane=cam->getFarPlane();
+		Vector3 pos=node->getPosition();
+		Vector3 camDir=cam->getDirection(),up=cam->getUp(),camPos=cam->getPosition();
+
+		mat4 view=lookAt(vec3(camPos.x,camPos.y,camPos.z),vec3(camPos.x+camDir.x,camPos.y+camDir.y,camPos.z+camDir.z),vec3(up.x,up.y,up.z));
+		mat4 proj=perspective(radians(fov),width/height,nearPlane,farPlane);
+
+		material->update();	
+		Shader *shader=material->getShader();
+		shader->setMat4(view,"view");
+		shader->setMat4(proj,"proj");
+		for(int i=0;i<numParticles;i++){
+			Vector3 dir=particles[i].dir;
+			if(getTime()-particles[i].time>=particles[i].timeToLive){
+				particles[i].time=getTime();
+				float factor=(float)(rand()%100)/100;
+				float spreadX=(float)(rand()%360)/180*PI,spreadY=(float)(rand()%360)/180*PI;
+				dir=Vector3(cos(abs(spreadX)>spread?spread:spreadX),sin(abs(spreadY)>spread?spread:spreadY),0);
+				particles[i].timeToLive=s64(1000*((highLife-lowLife)*factor+lowLife));
+				particles[i].mat=translate(mat4(1.f),vec3(dir.x,dir.y,dir.z));
+			}
+			dir=dir.norm()*direction.getLengthSq();
+			float lifePercentage=(float)(getTime()-particles[i].time)/particles[i].timeToLive;
+			particles[i].color=startColor+(endColor-startColor)*lifePercentage;
+			particles[i].size=startSize+(endSize-startSize)*lifePercentage;
+			particles[i].mat=translate(particles[i].mat,vec3(dir.x,dir.y,dir.z));
+
+		}
+		for(int i=0;i<numParticles;i++){
+			for(int j=0;j<numParticles-1;j++){
+				mat4 m1=particles[j].mat,m2=particles[j+1].mat;
+				Vector3 v1=Vector3(m1[3][0],m1[3][1],m1[3][2]);
+				Vector3 v2=Vector3(m2[3][0],m2[3][1],m2[3][2]);
+				float d1=cos(camDir.getAngleBetween((v1-camPos).norm()))*camPos.getDistanceFrom(v1);
+				float d2=cos(camDir.getAngleBetween((v2-camPos).norm()))*camPos.getDistanceFrom(v2);
+				if(d1<d2){
+					swap(particles[j],particles[j+1]);
+				}
+			}
+		}
+		for(int i=0;i<numParticles;i++){
+			shader->setMat4(particles[i].mat,"model["+to_string(i)+"]");
+			shader->setVec4(particles[i].color,"color["+to_string(i)+"]");
+			shader->setVec2(particles[i].size,"size["+to_string(i)+"]");
+		}
+			
+		glBindVertexArray(VAO);
+		glDrawElementsInstanced(GL_TRIANGLES,6,GL_UNSIGNED_INT,0,numParticles);	
+	}
+}