(20111215) 12:00

Entity.c

@@ -1,37 +1,225 @@
-#ifndef _ENTITY_H_
-#define _ENTITY_H_
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
 
+#include "Util.h"
+#include "Draw.h"
 
-////////////////////////////////////////////////
-// Entity //
-////////////
-// Reference to an entity.
-typedef void *Entity;
+#include "Entity.h"
 
 
 /////////////////////////////
-// Entity_Create
+// Entity_New
 //
-// Creates an entity.
-Entity Entity_Create(
-	int x,int y,
-	void (*process)(Entity ent,void *data),
-	void *data);
+//
+Entity *Entity_New(){
+	Entity *e;
+
+	e=malloc(sizeof(Entity));
+
+	e->type=0;
+	vec2_set(e->pos,0.0f,0.0f);
+
+	vec2_set(e->vel,0.0f,0.0f);
+	e->radius=1.0f;
+	e->mass=1.0f;
+	e->elast=0.0f;
+	e->fric_static=1.0f;
+	e->fric_dynamic=0.0f;
+
+	e->img=NULL;
+
+	e->proc=NULL;
+	e->postproc=NULL;
+
+	return(e);
+}
 
 
 /////////////////////////////
-// Entity_Create
+// Entity_Destroy
 //
-// Creates an entity.
+//
+void Entity_Destroy(Entity *e){
+	free(e);
+}
+
 
 /////////////////////////////
-// Entity_CreateClass
+// Entity_Copy
 //
-// Initializes the game.
-void Entity_CreateClass(char *name,
-	void *(*createdata)(),
-	void (*process)(Entity ent,void *data));
+//
+Entity *Entity_Copy(Entity *e){
+	Entity *n;
+
+	n=Entity_New();
+
+	n->type=e->type;
+	vec2_set(n->pos,e->pos[0],e->pos[1]);
+
+	vec2_set(n->vel,e->vel[0],e->vel[1]);
+	n->radius=e->radius;
+	n->mass=e->mass;
+	n->elast=e->elast;
+	n->fric_static=e->fric_static;
+	n->fric_dynamic=e->fric_dynamic;
+
+	n->img=e->img;
+
+	n->proc=e->proc;
+	n->postproc=e->postproc;
+
+	return(n);
+}
 
 
+/////////////////////////////
+// Entity_Draw
+//
+//
+void Entity_Draw(Entity *e){
+	if(e->img)
+		Draw_DrawImg(e->img,e->pos[0],e->pos[1]);
+}
 
-#endif
+
+/////////////////////////////
+// Entity_Process
+//
+//
+void Entity_Process(Entity *b){
+
+	// Launch method
+	if(b->proc){
+		b->proc(b);
+	}
+}
+
+
+/////////////////////////////
+// Entity_PostProcess
+//
+//
+void Entity_PostProcess(Entity *e){
+	float qlen,len;
+
+	// Launch method
+	if(e->postproc){
+		e->postproc(e);
+	}
+
+	// Determine if there is movement
+	qlen=vec2_dot(e->vel,e->vel);
+	if(qlen>0.0f){
+
+		// Update position
+		vec2_plus(e->pos,e->pos,e->vel);
+
+		// Aply friction
+		len=sqrtf(qlen);
+		if(len<e->fric_static){
+			// Stopped by static friction
+			vec2_set(e->vel,0,0);
+		}else{
+			// Aply dynamic friction
+			vec2_scale(e->vel,e->vel,
+				1.0f-(e->fric_dynamic+(e->fric_static/len)));
+		}
+	}
+}
+
+
+/////////////////////////////
+// Entity_Collide
+//
+//
+int Entity_Collide(Entity *b1,Entity *b2){
+	float t;
+	vec2 n;
+	vec2 cir1[2];
+	vec2 cir1i,cir2i;
+	Entity *b_aux;
+
+	// FIX: Swap colision order based on moving object
+	if(vec2_dot(b1->vel,b1->vel)<vec2_dot(b2->vel,b2->vel)){
+		b_aux=b1;
+		b1=b2;
+		b2=b_aux;
+	}
+
+	// Prepare testing vectors
+	vec2_copy(cir1[0],b1->pos);
+	vec2_plus(cir1[1],b1->pos,b1->vel);
+	vec2_minus(cir1[1],cir1[1],b2->vel);
+
+	if(Colision_CircleCircle(cir1,b1->radius,b2->pos,b2->radius,&t,n)){
+		float moment;
+		vec2 temp,temp2;
+		float elast;
+
+		// Collision response
+
+		if(b1->mass>0.0f && b2->mass>0.0f){
+			// Calculate elasticity
+			elast=(b1->mass*b1->elast+b2->mass*b2->elast)/
+				(b1->mass+b2->mass);
+
+			// Collision between two massed balls
+			moment=((1.0f+elast)*b1->mass*b2->mass*
+						(vec2_dot(b1->vel,n)+vec2_dot(b2->vel,n)))
+					/(b1->mass+b2->mass);
+			vec2_scale(temp,n,moment/b1->mass);
+			vec2_minus(b1->vel,b1->vel,temp);
+			vec2_scale(temp,n,moment/b2->mass);
+			vec2_plus(b2->vel,b2->vel,temp);
+		}else
+		if(b1->mass>0.0f && b2->mass<=0.0f){
+			// Collision between a massed ball and a fixed ball
+			moment=(1.0f+b1->elast)*
+						(vec2_dot(b1->vel,n));
+			vec2_scale(temp,n,moment);
+			vec2_minus(b1->vel,b1->vel,temp);
+		}else
+		if(b1->mass<=0.0f && b2->mass>0.0f){
+			// Collision between a massed ball and a fixed ball
+			// (imposible, but better safe)
+			moment=(1.0f+b2->elast)*
+						(vec2_dot(b2->vel,n));
+			vec2_scale(temp,n,moment);
+			vec2_plus(b2->vel,b2->vel,temp);
+		}else{
+			// Collision between 2 fixed balls
+			// (imposible, but better safe)
+			vec2_set(b1->vel,0,0);
+			vec2_set(b2->vel,0,0);
+		}
+		return(1);
+	}
+	return(0);
+}
+
+
+/////////////////////////////
+// Entity_AddVelLimit
+//
+//
+void Entity_AddVelLimit(Entity *e,vec2 vel,float limit){
+	float vlen_orig,vlen;
+	vec2 dir,vel_temp;
+
+	// Normalize vel getting vel
+	vlen_orig=sqrtf(vec2_dot(vel,vel));
+	vec2_scale(dir,vel,1.0f/vlen_orig);
+
+	// Limit velocity
+	vlen=vec2_dot(e->vel,dir);
+	if(vlen<limit){
+		vlen=limit-vlen;
+		if(vlen>vlen_orig){
+			vlen=vlen_orig;
+		}
+		vec2_scale(vel_temp,dir,vlen);
+		vec2_plus(e->vel,e->vel,vel_temp);
+	}
+
+}