RogueLife/src/comp/particle.c

#include "comp/entity.h"
#include "comp/physical.h"
#include "comp/particle.h"
#include "anim.h"
#include "geometry.h"
#include "util.h"

#include <gint/defs/attributes.h>
#include <gint/display.h>
#include <stdio.h>

entity_t *particle_make_damage(entity_t *target, int damage, int color)
{
    entity_t *e = entity_make(particle);
    particle_t *p = getcomp(e, particle);

    physical_t *target_p = getcomp(target, physical);

    p->type = PARTICLE_DAMAGE;
    p->plane = CEILING;
    p->bound_to_entity = false;
    p->x = target_p->x;
    p->y = target_p->y;
    p->z = fix(0.5);
    p->age = 0;

    p->DAMAGE.damage = damage;
    p->DAMAGE.color = color;

    return e;
}

entity_t *particle_make_dash(entity_t *target)
{
    entity_t *e = entity_make(particle);
    particle_t *p = getcomp(e, particle);

    physical_t *target_p = getcomp(target, physical);

    p->type = PARTICLE_DASH;
    p->plane = HORIZONTAL;
    p->bound_to_entity = false;
    p->x = target_p->x;
    p->y = target_p->y;
    p->z = 0;
    p->age = 0;

    return e;
}

entity_t *particle_make_buff(entity_t *target, int color)
{
    entity_t *e = entity_make(particle);
    particle_t *p = getcomp(e, particle);

    p->type = PARTICLE_BUFF;
    p->plane = CEILING;
    p->bound_to_entity = true;
    p->bound_entity = target;
    p->z = fix(0.5);
    p->age = 0;

    p->BUFF.color = color;

    return e;
}

static bool damage_update(particle_t *p, GUNUSED fixed_t dt)
{
    return p->age >= 300;
}

static void damage_render(int x, int y, particle_t const *p)
{
    font_damage_print(x, y, p->DAMAGE.color, DTEXT_CENTER, DTEXT_MIDDLE,
        p->DAMAGE.damage);
}

static bool dash_update(particle_t *p, GUNUSED fixed_t dt)
{
    return p->age >= 256;
}

static void dash_render(int x, int y, particle_t const *p)
{
    /* 32 * (1 - age/256) */
    int radius = 32 - (p->age >> 3);

    for(int dx = -5; dx <= +5; dx++)
    for(int dy = -5; dy <= +5; dy++) {
        if(dx * dx + dy * dy <= radius) {
            int index = 396 * (y + dy) + (x + dx);
            gint_vram[index] = ~((~gint_vram[index] & 0xf7de) >> 1);
        }
    }
}

static bool buff_update(particle_t *p, GUNUSED fixed_t dt)
{
    int total_ms = 0;
    anim_frame_t const *frame = anims_item_buff.start[0];
    while(frame) {
        total_ms += frame->duration;
        frame = frame->next;
    }

    return p->age >= total_ms;
}

static void buff_render(int x, int y, particle_t const *p)
{
    int ms = p->age;
    anim_frame_t const *frame = anims_item_buff.start[0];
    while(frame && ms > frame->duration) {
        ms -= frame->duration;
        frame = frame->next;
    }
    if(!frame)
        return;

    /* Find black and white in the palette */
    int black_index = -1;
    int white_index = -1;
    for(int i = 0; i < frame->sheet->color_count; i++) {
        if(black_index == -1 && frame->sheet->palette[i] == 0x0000)
            black_index = i;
        if(white_index == -1 && frame->sheet->palette[i] == 0xffff)
            white_index = i;
    }

    /* Render while swapping black for p->BUFF.color */
    frame->sheet->palette[black_index] = p->BUFF.color;
    frame->sheet->palette[white_index] = ~((~p->BUFF.color & 0xf7de) >> 1);

    dsubimage_p4(x - frame->cx, y - frame->cy, frame->sheet,
        frame->x, frame->y, frame->w, frame->h, DIMAGE_NONE);

    frame->sheet->palette[black_index] = 0x0000;
    frame->sheet->palette[white_index] = 0xffff;
}

//---
// Generic functions
//---

bool particle_update(particle_t *p, fixed_t dt)
{
    p->age += fround(dt * 1000);

    if(p->type == PARTICLE_DAMAGE)
        return damage_update(p, dt);
    if(p->type == PARTICLE_DASH)
        return dash_update(p, dt);
    if(p->type == PARTICLE_BUFF)
        return buff_update(p, dt);

    return true;
}

void particle_render(int x, int y, particle_t const *p)
{
    if(p->type == PARTICLE_DAMAGE)
        return damage_render(x, y, p);
    if(p->type == PARTICLE_DASH)
        return dash_render(x, y, p);
    if(p->type == PARTICLE_BUFF)
        return buff_render(x, y, p);
}