Particles.

common.mk

@@ -17,7 +17,7 @@ OBJS += init.o input.o io.o items.o
 OBJS += lookup.o
 OBJS += main.o map.o maths.o
 OBJS += objectives.o
-OBJS += player.o
+OBJS += particles.o player.o
 OBJS += quadtree.o
 OBJS += sound.o sprites.o
 OBJS += text.o textures.o title.o triggers.o

src/combat/combat.c

@@ -27,7 +27,7 @@ void preFire(Entity *e)
 {
 	if (e->flags & EF_WEIGHTLESS)
 	{
-		if (world.bob->y < e->y && e->isOnGround && (int) (rand() * 4) == 0)
+		if (world.bob->y < e->y && e->isOnGround && (int) (rand() % 4) == 0)
 		{
 			e->dy = JUMP_POWER;
 		}

src/defs.h

@@ -140,6 +140,19 @@ enum
 	MS_MISSING_HEART_CELL
 };
 
+enum
+{
+	PLANE_BACKGROUND,
+	PLANE_FOREGROUND
+};
+
+enum
+{
+	PT_LINE,
+	PT_POINT,
+	PT_TEXTURED
+};
+
 enum
 {
 	MSG_STANDARD,

src/structs.h

@@ -25,6 +25,8 @@ typedef struct Entity Entity;
 typedef struct Objective Objective;
 typedef struct Trigger Trigger;
 typedef struct Marker Marker;
+typedef struct Particle Particle;
+typedef struct Sprite Sprite;
 
 typedef struct {
 	int debug;
@@ -196,10 +198,36 @@ struct Quadtree {
 	Quadtree *node[4];
 };
 
+struct Sprite {
+	int numFrames;
+	int times[1];
+};
+
+struct Particle {
+	int type;
+	int plane;
+	float health;
+	float x;
+	float y;
+	float dx;
+	float dy;
+	int size;
+	float r;
+	float g;
+	float b;
+	int spriteIndex;
+	double spriteTime;
+	int spriteFrame;
+	int destroyAfterAnim;
+	int onScreen;
+	Particle *next;
+};
+
 typedef struct {
 	Entity *bob;
 	Map map;
 	Entity entityHead, *entityTail;
+	Particle particleHead, *particleTail;
 	int allObjectivesComplete;
 	int currentStatus;
 	int isBossMission;

src/system/sprites.c

@@ -24,3 +24,8 @@ int getSpriteIndex(char *name)
 {
 	return 0;
 }
+
+Sprite *getSprite(int i)
+{
+	return NULL;
+}

src/util/maths.c

@@ -30,6 +30,11 @@ int rrnd(int low, int high)
 	return low + rand() % ((high - low) + 1);
 }
 
+double randF(void)
+{
+    return (double)rand() / (double)((unsigned)RAND_MAX + 1);
+}
+
 int getPercent(float current, float total)
 {
 	return (current / total) * 100;
@@ -77,6 +82,21 @@ void getSlope(int x1, int y1, int x2, int y2, float *dx, float *dy)
 	*dy /= steps;
 }
 
+float wrap(float value, float low, float high)
+{
+	if (value < low)
+	{
+		return high;
+	}
+
+	if (value > high)
+	{
+		return low;
+	}
+
+	return value;
+}
+
 int lineIntersectsRect(SDL_Rect r, int x1, int y1, int x2, int y2)
 {
 	return 0;

src/world/particles.c

@@ -0,0 +1,268 @@
+/*
+Copyright (C) 2018 Parallel Realities
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#include "particles.h"
+
+static void animate(Particle *p);
+static Particle *createParticle(void);
+
+static int bloodSprite[3];
+static int explosionSprite[2];
+static int flameSprite;
+static int smokeSprite;
+static int teleportStarSprite;
+
+void initParticles(void)
+{
+	bloodSprite[0] = getSpriteIndex("Blood1");
+	bloodSprite[1] = getSpriteIndex("Blood2");
+	bloodSprite[2] = getSpriteIndex("Blood3");
+
+	explosionSprite[0] = getSpriteIndex("Explosion1");
+	explosionSprite[1] = getSpriteIndex("Explosion2");
+
+	flameSprite = getSpriteIndex("Flame");
+	smokeSprite = getSpriteIndex("Smoke");
+
+	teleportStarSprite = getSpriteIndex("TeleportStar");
+}
+
+void addBlood(float x, float y)
+{
+	Particle *p;
+	
+	p = createParticle();
+	p->type = PT_TEXTURED;
+	p->x = x;
+	p->y = y;
+	p->size = 1;
+	p->dy = 1;
+	p->health = rrnd(5, 30);
+	p->spriteIndex = bloodSprite[(int) (rand() % 3)];
+}
+
+void addSparkParticles(float x, float y)
+{
+	Particle *p;
+	int i;
+	float c;
+	
+	for (i = 0; i < 3; i++)
+	{
+		p = createParticle();
+		p->x = x;
+		p->y = y;
+		p->dx = rand() % 300 - rand() % 300;
+		p->dx /= 100;
+		p->dy = rand() % 300 - rand() % 300;
+		p->dy /= 100;
+		p->health = rrnd(5, 30);
+		
+		c = 50 + (rand() % 50);
+		c /= 100;
+		
+		p->r = p->g = p->b = c;
+	}
+}
+
+void addSmokeParticles(float x, float y)
+{
+	Particle *p;
+	
+	p = createParticle();
+	p->type = PT_TEXTURED;
+	p->x = x;
+	p->y = y;
+	p->size = 1;
+	p->health = rrnd(5, 30);
+	p->spriteIndex = smokeSprite;
+	p->spriteTime = 5;
+	p->spriteFrame = 0;
+	p->destroyAfterAnim = 1;
+}
+
+void addFlameParticles(float x, float y)
+{
+	Particle *p;
+	
+	p = createParticle();
+	p->type = PT_TEXTURED;
+	p->x = x;
+	p->y = y;
+	p->size = 1;
+	p->health = rrnd(5, 30);
+	p->spriteIndex = flameSprite;
+	p->spriteTime = 5;
+	p->spriteFrame = 0;
+	p->destroyAfterAnim = 1;
+}
+
+
+void addExplosionParticles(float x, float y, float radius, int amount)
+{
+	int i;
+	Particle *p;
+	
+	for (i = 0; i < amount; i++)
+	{
+		p = createParticle();
+		p->type = PT_TEXTURED;
+		p->x = x;
+		p->y = y;
+		p->dx = (randF() - randF()) * radius;
+		p->dx /= 5;
+		p->dy = (randF() - randF()) * radius;
+		p->dy /= 5;
+		p->health = rrnd(FPS / 4, FPS);
+		p->spriteTime = 5;
+		p->spriteFrame = 0;
+		p->spriteIndex = explosionSprite[i % 2];
+	}
+}
+
+void addTeleportStar(float x, float y)
+{
+	Particle *p;
+	
+	p = createParticle();
+	p->type = PT_TEXTURED;
+	p->x = x;
+	p->y = y;
+	p->dx = ((randF() - randF()) * 4);
+	p->dy = ((randF() - randF()) * 4);
+	p->health = rrnd(FPS / 4, FPS);
+	p->r = p->g = p->b = 1.0f;
+	p->spriteIndex = teleportStarSprite;
+	p->spriteFrame = (rand() % 12);
+	p->plane = PLANE_FOREGROUND;
+}
+
+void addTeleportStars(Entity *e)
+{
+	int x, y, i;
+	
+	x = (int) (e->x + (e->w / 2));
+	y = (int) (e->y + (e->h / 2));
+
+	for (i = 0 ; i < 32 ; i++)
+	{
+		addTeleportStar(x, y);
+	}
+}
+
+void addMIATeleportStars(float x, float y)
+{
+	Particle *p;
+	
+	p = createParticle();
+	p->type = PT_TEXTURED;
+	p->x = x;
+	p->y = y;
+	p->dy = -(1 + (rand()) % 4);
+	p->health = FPS * 3;
+	p->r = p->g = p->b = 1.0f;
+	p->spriteIndex = teleportStarSprite;
+	p->spriteFrame = (rand() % 12);
+	p->plane = PLANE_FOREGROUND;
+}
+
+void addTeleporterEffect(float x, float y)
+{
+	Particle *p;
+	
+	p = createParticle();
+	p->type = PT_TEXTURED;
+	p->x = x;
+	p->y = y;
+	p->dx = 0;
+	p->dy = -(randF() * 2);
+	p->health = rrnd(FPS / 4, FPS);
+	p->r = p->g = p->b = 1.0f;
+	p->spriteIndex = teleportStarSprite;
+	p->spriteFrame = (rand() % 12);
+}
+
+void doParticles(void)
+{
+	Particle *p, *prev;
+	int camMidX, camMidY;
+	
+	camMidX = camera.x + (SCREEN_WIDTH / 2);
+	camMidY = camera.y + (SCREEN_HEIGHT / 2);
+	
+	prev = &world.particleHead;
+
+	for (p = world.particleHead.next ; p != NULL ; p = p->next)
+	{
+		animate(p);
+
+		p->x += p->dx;
+		p->y += p->dy;
+		
+		p->onScreen = 0;
+
+		if (--p->health <= 0 || (p->destroyAfterAnim && p->spriteTime == -1))
+		{
+			if (p == world.particleTail)
+			{
+				world.particleTail = prev;
+			}
+			
+			prev->next = p->next;
+			free(p);
+			p = prev;
+		}
+		else if (getDistance(camMidX, camMidY, p->x, p->y) < SCREEN_WIDTH)
+		{
+			p->onScreen = 1;
+		}
+		
+		prev = p;
+	}
+}
+
+static void animate(Particle *p)
+{
+	Sprite *s;
+	
+	if (p->spriteTime != -1)
+	{
+		p->spriteTime--;
+
+		if (p->spriteTime <= 0)
+		{
+			s = getSprite(p->spriteIndex);
+			p->spriteFrame = (int) wrap(++p->spriteFrame, 0, s->numFrames);
+			p->spriteTime = s->times[p->spriteFrame];
+		}
+	}
+}
+
+static Particle *createParticle(void)
+{
+	Particle *p;
+	
+	p = malloc(sizeof(Particle));
+	memset(p, 0, sizeof(Particle));
+	world.particleTail->next = p;
+	world.particleTail = p;
+	
+	return p;
+}

src/world/particles.h

@@ -0,0 +1,31 @@
+/*
+Copyright (C) 2018 Parallel Realities
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+#include "../common.h"
+
+extern Sprite *getSprite(int i);
+extern int getSpriteIndex(char *name);
+extern float wrap(float value, float low, float high);
+extern int rrnd(int low, int high);
+extern double randF(void);
+extern int getDistance(int x1, int y1, int x2, int y2);
+
+extern Camera camera;
+extern World world;