LCOM1920-T5G03

///SPRITE

#include "utils.h"

#include "fast_math.h"

#include <math.h>

struct basic_sprite{

    uint8_t *map;

    uint16_t w, h;

    int16_t u0, v0;

};

basic_sprite_t* (basic_sprite_ctor)(const char **xpm, int16_t u0, int16_t v0){

    basic_sprite_t *ret = malloc(sizeof(basic_sprite_t));

    if(ret == NULL) return NULL;

    enum xpm_image_type type = XPM_8_8_8_8;

    xpm_image_t img;

    ret->map = xpm_load((xpm_map_t)xpm, type, &img);

    if(ret->map == NULL){

        free(ret);

        return NULL;

    }

    ret->w = img.width;

    ret->h = img.height;

    ret->u0 = u0;

    ret->v0 = v0;

    return ret;

}

void (basic_sprite_dtor)(basic_sprite_t *p){

    if(p == NULL) return;

    free(p->map);

    free(p);

}

const uint8_t* (basic_sprite_get_map)(const basic_sprite_t *p){ return p->map; }

uint16_t       (basic_sprite_get_w)  (const basic_sprite_t *p){ return p->w  ; }

uint16_t       (basic_sprite_get_h)  (const basic_sprite_t *p){ return p->h  ; }

int16_t        (basic_sprite_get_u0) (const basic_sprite_t *p){ return p->u0 ; }

int16_t        (basic_sprite_get_v0) (const basic_sprite_t *p){ return p->v0 ; }

struct sprite{

    const basic_sprite_t *bsp;

    int16_t x, y; //position in screen

    double theta, s, c;

    double scale;

};

sprite_t* (sprite_ctor)(const basic_sprite_t *bsp){

    sprite_t *ret = malloc(sizeof(sprite_t));

    if(ret == NULL) return NULL;

    ret->bsp = bsp;

    ret->x = 0;

    ret->y = 0;

    sprite_set_angle(ret, 0.0);

    ret->scale = 1.0;

    return ret;

}

void (sprite_dtor)(sprite_t *p){

    if(p == NULL) return;

    free(p);

}

void (sprite_set_pos)   (sprite_t *p, int16_t x , int16_t y ){ p->x = x; p->y = y; }

void (sprite_set_angle) (sprite_t *p, double angle          ){ p->theta = angle; p->c = fm_cos(p->theta); p->s = fm_sin(p->theta); }

void (sprite_set_scale) (sprite_t *p, double scale          ){ p->scale = scale; }

int16_t  (sprite_get_x)(const sprite_t *p){ return p->x; }

int16_t  (sprite_get_y)(const sprite_t *p){ return p->y; }

void (sprite_src2pic)(const sprite_t *p, int16_t x, int16_t y, int16_t *u, int16_t *v){

    double dx = (x - p->x)/p->scale;

    double dy = (y - p->y)/p->scale;

    int16_t du = dx*p->c - dy*p->s + 0.5;

    int16_t dv = dx*p->s + dy*p->c + 0.5;

    *u = du + basic_sprite_get_u0(p->bsp);

    *v = dv + basic_sprite_get_v0(p->bsp);

}

void (sprite_pic2src)(const sprite_t *p, int16_t u, int16_t v, int16_t *x, int16_t *y){

    int16_t du = u - basic_sprite_get_u0(p->bsp);

    int16_t dv = v - basic_sprite_get_v0(p->bsp);

    double dx =  du*p->c + dv*p->s;

    double dy = -du*p->s + dv*p->c;

    *x = dx*p->scale + 0.5 + p->x;

    *y = dy*p->scale + 0.5 + p->y;

}

void (sprite_draw)(const sprite_t *p){

    const uint16_t w = basic_sprite_get_w(p->bsp);

    const uint16_t h = basic_sprite_get_h(p->bsp);

    int16_t xmin, xmax, ymin, ymax; {

        int16_t x, y;

        sprite_pic2src(p, 0, 0, &x, &y);

        xmin = x; xmax = x; ymin = y; ymax = y;

        sprite_pic2src(p, w, 0, &x, &y);

        xmin = min(x, xmin); xmax = max(x, xmax); ymin = min(y, ymin); ymax = max(y, ymax);

        sprite_pic2src(p, 0, h, &x, &y);

        xmin = min(x, xmin); xmax = max(x, xmax); ymin = min(y, ymin); ymax = max(y, ymax);

        sprite_pic2src(p, w, h, &x, &y);

        xmin = min(x, xmin); xmax = max(x, xmax); ymin = min(y, ymin); ymax = max(y, ymax);

        xmin = max(xmin-2, 0); xmax = min(xmax+2, graph_get_XRes());

        ymin = max(ymin-2, 0); ymax = min(ymax+2, graph_get_YRes());

    }

    const uint8_t *map = basic_sprite_get_map(p->bsp);

    const uint16_t bytes_pixel = graph_get_bytes_pixel();

    for(int16_t u, v, y = ymin; y < ymax; ++y){

        unsigned pos = (xmin + y*graph_get_XRes())*bytes_pixel;

        for(int16_t x = xmin; x < xmax; ++x, pos += bytes_pixel){

            sprite_src2pic(p, x, y, &u, &v);

            if(0 <= u && u < w && 0 <= v && v < h){

                uint32_t c = *(uint32_t*)(map + (v*w + u)*4);

                if(GET_ALP(c) < 0x7F)

                    graph_set_pixel_pos(pos, c);

            }

        }

    }

}

/// sprite_draw is implemented in graph.c