Player bleed based on health (#95)

This change makes the player bleed consistently based on how much damage
has been taken.

Author: LiquidityC

src/particle_emitter.c

@@ -13,6 +13,7 @@ particle_emitter_create(void)
 	emitter->timer = _timer_create();
 	emitter->timestep = 1;
 	emitter->enabled = false;
+	emitter->userdata = NULL;
 	return emitter;
 }
 
@@ -34,7 +35,7 @@ particle_emitter_render(ParticleEmitter *emitter)
 	timer_start(emitter->timer);
 
 	if (emitter->particle_func)
-		emitter->particle_func(emitter->pos, emitter->dim);
+		emitter->particle_func(emitter->pos, emitter->dim, emitter->userdata);
 	else
 		error("Particle emitter missing particle_func");
 }

src/particle_emitter.h

@@ -27,7 +27,8 @@ typedef struct ParticleEmitter {
 	Timer *timer;
 	Position pos;
 	Dimension dim;
-	void (*particle_func)(Position, Dimension);
+	void (*particle_func)(Position, Dimension, void *userdata);
+	void *userdata;
 	bool enabled;
 } ParticleEmitter;
 

src/particle_engine.c

@@ -100,8 +100,9 @@ particle_engine_init(void)
 }
 
 void
-particle_engine_bleed(Position pos, Dimension dim)
+particle_engine_bleed(Position pos, Dimension dim, void *userdata)
 {
+	(void) userdata;
 	particle_engine_bloodspray(pos, dim, 10);
 }
 
@@ -267,8 +268,9 @@ particle_engine_speed_lines(Position pos, Dimension dim, bool horizontal)
 }
 
 void
-particle_engine_bloodlust(Position pos, Dimension dim)
+particle_engine_bloodlust(Position pos, Dimension dim, void *userdata)
 {
+	(void) userdata;
 	particle_engine_sparkle(pos, dim, C_RED, false);
 }
 

src/particle_engine.h

@@ -29,7 +29,7 @@ void
 particle_engine_init(void);
 
 void
-particle_engine_bleed(Position pos, Dimension dim);
+particle_engine_bleed(Position pos, Dimension dim, void *userdata);
 
 void
 particle_engine_bloodspray(Position, Dimension, unsigned int count);
@@ -50,7 +50,7 @@ void
 particle_engine_speed_lines(Position, Dimension, bool horizontal);
 
 void
-particle_engine_bloodlust(Position, Dimension);
+particle_engine_bloodlust(Position, Dimension, void *userdata);
 
 void
 particle_engine_sparkle(Position, Dimension, SDL_Color, bool global);

src/player.c

@@ -64,6 +64,15 @@ levelup(Player *player)
 	player->stats.hp = player->stats.maxhp;
 }
 
+static void
+player_particle_bleed(Position pos, Dimension dim, void *userdata)
+{
+	Player *p = userdata;
+	float perc = (float) p->stats.hp / p->stats.maxhp;
+	Uint32 particle_count = (Uint32) (20.0f * perc);
+	particle_engine_bloodspray(pos, dim, particle_count);
+}
+
 void
 player_levelup(Player *player)
 {
@@ -320,15 +329,26 @@ player_turn(Player *player, Vector2d *direction)
 	}
 }
 
+void
+player_update_pos(Player *player, Uint32 dx, Uint32 dy)
+{
+	player->sprite->pos.x += dx;
+	player->sprite->pos.y += dy;
+
+	Position pos = player->sprite->pos;
+	pos.x += 5;
+	pos.y += 5;
+	particle_emitter_update(player->bleed_emitter, pos, DIM(10, 10));
+}
+
 static void
 move(Player *player, RoomMatrix *matrix, Vector2d direction)
 {
 	player_turn(player, &direction);
 
 	Position lastPos = position_to_matrix_coords(&player->sprite->pos);
 
-	player->sprite->pos.x += TILE_DIMENSION * (int) direction.x;
-	player->sprite->pos.y += TILE_DIMENSION * (int) direction.y;
+	player_update_pos(player, TILE_DIMENSION * (int) direction.x, TILE_DIMENSION * (int) direction.y);
 
 	if (!has_collided(player, matrix, direction)) {
 		action_spent(player);
@@ -547,6 +567,13 @@ player_create(class_t class, Camera *cam)
 	player->equipment.keys		= 0;
 	player->stateData.shopOwnerKiller = false;
 
+	ParticleEmitter *emitter = particle_emitter_create();
+	emitter->timestep = 2000;
+	emitter->enabled = false;
+	emitter->particle_func = particle_engine_bleed;
+	emitter->userdata = player;
+	player->bleed_emitter		= emitter;
+
 	build_sword_animation(player, cam->renderer);
 
 	memset(&player->skills,
@@ -701,6 +728,8 @@ player_render(Player *player, Camera *cam)
 		projectile_render(projectile->data, cam);
 		projectile = projectile->next;
 	}
+
+	particle_emitter_render(player->bleed_emitter);
 }
 
 void
@@ -759,6 +788,9 @@ player_update(UpdateData *data)
 	player->projectiles = remaining;
 
 	animation_update(player->swordAnimation);
+
+	uint32_t damage_taken = player->stats.maxhp - player->stats.hp;
+	player->bleed_emitter->enabled = damage_taken >= player->stats.maxhp / 2;
 }
 
 static void
@@ -789,6 +821,8 @@ player_destroy(Player *player)
 		player->skills[i] = NULL;
 	}
 
+	particle_emitter_destroy(player->bleed_emitter);
+
 	free(player);
 }
 

src/player.h

@@ -26,6 +26,8 @@
 #include "linkedlist.h"
 #include "input.h"
 #include "artifact.h"
+#include "particle_engine.h"
+#include "particle_emitter.h"
 
 #define PLAYER_SKILL_COUNT 5
 
@@ -97,6 +99,7 @@ typedef struct Player {
 	PlayerEquipment equipment;
 	PlayerStateData stateData;
 	PlayerEffects effects;
+	ParticleEmitter *bleed_emitter;
 } Player;
 
 Player*
@@ -132,6 +135,9 @@ player_render_toplayer(Player*, Camera*);
 void
 player_turn(Player*, Vector2d *dir);
 
+void
+player_update_pos(Player*, Uint32 dx, Uint32 dy);
+
 void
 player_destroy(Player*);
 

src/skill.c

@@ -640,8 +640,8 @@ skill_backstab(Skill *skill, SkillData *data)
 
 	mixer_play_effect(SWING0 + get_random(2));
 
-	data->player->sprite->pos.x += (int) data->direction.x * TILE_DIMENSION;
-	data->player->sprite->pos.y += (int) data->direction.y * TILE_DIMENSION;
+	player_update_pos(data->player, data->direction.x * TILE_DIMENSION,
+			  data->direction.y * TILE_DIMENSION);
 	player_turn(data->player, &reverseDirection);
 	animation_run(data->player->swordAnimation);
 
@@ -828,8 +828,7 @@ skill_charge(Skill *skill, SkillData *data)
 	Position playerOriginPos = player->sprite->pos;
 	Sint32 xdiff = destination.x - playerStartPos.x;
 	Sint32 ydiff = destination.y - playerStartPos.y;
-	player->sprite->pos.x += xdiff * TILE_DIMENSION;
-	player->sprite->pos.y += ydiff * TILE_DIMENSION;
+	player_update_pos(player, xdiff * TILE_DIMENSION, ydiff * TILE_DIMENSION);
 	Position playerDestinationPos = player->sprite->pos;
 	player_turn(data->player, &data->direction);
 
@@ -912,8 +911,7 @@ skill_blink(Skill *skill, SkillData *data)
 	Position playerOriginPos = player->sprite->pos;
 	Sint32 xdiff = destination.x - playerStartPos.x;
 	Sint32 ydiff = destination.y - playerStartPos.y;
-	player->sprite->pos.x += xdiff * TILE_DIMENSION;
-	player->sprite->pos.y += ydiff * TILE_DIMENSION;
+	player_update_pos(player, xdiff * TILE_DIMENSION, ydiff * TILE_DIMENSION);
 	Position playerDestinationPos = player->sprite->pos;
 	player_turn(data->player, &data->direction);