#include "kknd.h"

/* =========================================================================
 * sprites.c - Procedural 2D sprite/terrain generation.
 * Recreates the chunky post-apocalyptic KKND look without using any
 * original game assets. All art is drawn at runtime into SDL textures.
 * ========================================================================= */

#define SURF_FMT SDL_PIXELFORMAT_RGBA32

static SDL_Surface *new_surf(int w, int h) {
    return SDL_CreateRGBSurfaceWithFormat(0, w, h, 32, SURF_FMT);
}

static void px(SDL_Surface *s, int x, int y, Uint8 r, Uint8 g, Uint8 b, Uint8 a) {
    if (x < 0 || y < 0 || x >= s->w || y >= s->h) return;
    Uint32 *p = (Uint32 *)((Uint8 *)s->pixels + y * s->pitch);
    Uint32 pix = (a << 24) | (b << 16) | (g << 8) | r;
    p[x] = pix;
}

static void fill_rect(SDL_Surface *s, int x, int y, int w, int h,
                      Uint8 r, Uint8 g, Uint8 b, Uint8 a) {
    for (int j = y; j < y + h; j++)
        for (int i = x; i < x + w; i++)
            px(s, i, j, r, g, b, a);
}

static void disc(SDL_Surface *s, int cx, int cy, int rad,
                 Uint8 r, Uint8 g, Uint8 b, Uint8 a) {
    for (int j = -rad; j <= rad; j++)
        for (int i = -rad; i <= rad; i++)
            if (i*i + j*j <= rad*rad)
                px(s, cx + i, cy + j, r, g, b, a);
}

static void ring(SDL_Surface *s, int cx, int cy, int rad, int t,
                 Uint8 r, Uint8 g, Uint8 b, Uint8 a) {
    for (int j = -rad; j <= rad; j++)
        for (int i = -rad; i <= rad; i++) {
            int d = i*i + j*j;
            if (d <= rad*rad && d >= (rad - t)*(rad - t))
                px(s, cx + i, cy + j, r, g, b, a);
        }
}

static void line(SDL_Surface *s, int x0, int y0, int x1, int y1,
                 Uint8 r, Uint8 g, Uint8 b, Uint8 a) {
    int dx = abs(x1 - x0), dy = -abs(y1 - y0);
    int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1;
    int err = dx + dy;
    for (;;) {
        px(s, x0, y0, r, g, b, a);
        if (x0 == x1 && y0 == y1) break;
        int e2 = 2 * err;
        if (e2 >= dy) { err += dy; x0 += sx; }
        if (e2 <= dx) { err += dx; y0 += sy; }
    }
}

static SDL_Color darken(SDL_Color c, float f) {
    return (SDL_Color){
        (Uint8)(c.r*f), (Uint8)(c.g*f), (Uint8)(c.b*f), c.a };
}
static SDL_Color lighten(SDL_Color c, float f) {
    return (SDL_Color){
        (Uint8)(c.r + (255-c.r)*f), (Uint8)(c.g + (255-c.g)*f),
        (Uint8)(c.b + (255-c.b)*f), c.a };
}

/* ---------------- unit sprites ---------------- */
/* Near-black outline first (KKND2 silhouette), then bright faction fill.
 * Geometry mirrors snapshot.c draw_unit atlas coords (center 15,15); SDL rotates live. */
SDL_Texture *sprites_make_unit(SDL_Renderer *r, UnitType t, Faction f) {
    int S = 30;
    SDL_Surface *s = new_surf(S, S);
    SDL_Color base = faction_color(f);
    SDL_Color dark = darken(base, 0.55f);
    SDL_Color lite = lighten(base, 0.45f);
    /* Tyre / mid-tone parity with snapshot draw_unit (mr/mg/mb). */
    const Uint8 tr = 70, tg = 65, tb = 58;
    const Uint8 ok = 18, og = 16, ob = 14; /* near-black outline */
    (void)dark;

    switch (t) {
    case UT_INFANTRY:
        /* boots/knees → torso/belt/pouches → pads → pack → helmet/visor/antenna → rifle+bayonet */
        disc(s, 11, 23, 3, ok, og, ob, 255);
        disc(s, 19, 23, 3, ok, og, ob, 255);
        disc(s, 11, 23, 2, base.r, base.g, base.b, 255);
        disc(s, 19, 23, 2, base.r, base.g, base.b, 255);
        fill_rect(s, 10, 24, 3, 2, 40, 36, 30, 255); /* boot L */
        fill_rect(s, 18, 24, 3, 2, 40, 36, 30, 255); /* boot R */
        fill_rect(s, 10, 20, 3, 2, 55, 50, 42, 255); /* knee pad L */
        fill_rect(s, 18, 20, 3, 2, 55, 50, 42, 255); /* knee pad R */
        disc(s, 15, 15, 9, ok, og, ob, 255);
        disc(s, 15, 15, 7, base.r, base.g, base.b, 255);
        fill_rect(s, 11, 17, 8, 2, 45, 42, 36, 255); /* belt */
        fill_rect(s, 12, 16, 2, 2, 60, 55, 45, 255); /* pouch L */
        fill_rect(s, 16, 16, 2, 2, 60, 55, 45, 255); /* pouch R */
        fill_rect(s, 9, 12, 3, 3, 50, 46, 40, 255); /* shoulder pad L */
        fill_rect(s, 19, 12, 3, 3, 50, 46, 40, 255); /* shoulder pad R */
        disc(s, 10, 16, 3, ok, og, ob, 255); /* backpack */
        disc(s, 10, 16, 2, 50, 46, 40, 255);
        fill_rect(s, 8, 15, 2, 3, 40, 38, 32, 255); /* pack strap */
        disc(s, 15, 8, 5, ok, og, ob, 255);
        disc(s, 15, 8, 4, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 12, 7, 5, 2, 30, 40, 50, 255); /* visor */
        line(s, 14, 6, 14, 1, 50, 46, 40, 255); /* antenna */
        line(s, 15, 6, 15, 0, lite.r, lite.g, lite.b, 255);
        line(s, 16, 14, 16, 0, 40, 36, 30, 255);
        line(s, 17, 14, 17, 1, 55, 50, 40, 255);
        line(s, 18, 14, 18, 2, 45, 40, 34, 255);
        disc(s, 17, 1, 2, 60, 55, 45, 255); /* muzzle tip */
        line(s, 17, 2, 20, 0, 70, 65, 55, 255); /* bayonet */
        line(s, 18, 2, 21, 1, 55, 50, 40, 255);
        break;
    case UT_BUGGY:
        /* fenders + bumper + cabin + roll bar + spare + exhaust + lights + MG */
        fill_rect(s, 2, 6, 26, 18, ok, og, ob, 255);
        fill_rect(s, 4, 8, 22, 14, base.r, base.g, base.b, 255);
        fill_rect(s, 3, 6, 6, 3, 45, 42, 36, 255); /* front fender L */
        fill_rect(s, 21, 6, 6, 3, 45, 42, 36, 255); /* front fender R */
        fill_rect(s, 3, 22, 6, 3, 45, 42, 36, 255); /* rear fender L */
        fill_rect(s, 21, 22, 6, 3, 45, 42, 36, 255); /* rear fender R */
        fill_rect(s, 1, 12, 3, 6, 55, 50, 40, 255); /* bumper */
        fill_rect(s, 2, 13, 1, 4, 90, 80, 55, 255);
        fill_rect(s, 6, 9, 10, 6, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 7, 8, 8, 3, 35, 55, 75, 255); /* windshield */
        line(s, 8, 10, 8, 4, lite.r, lite.g, lite.b, 255); /* roll bar L */
        line(s, 9, 10, 9, 4, 50, 46, 40, 255);
        line(s, 18, 10, 18, 4, lite.r, lite.g, lite.b, 255); /* roll bar R */
        line(s, 17, 10, 17, 4, 50, 46, 40, 255);
        line(s, 8, 4, 18, 4, lite.r, lite.g, lite.b, 255);
        line(s, 8, 5, 18, 5, 50, 46, 40, 255);
        disc(s, 25, 16, 3, ok, og, ob, 255); /* spare tyre */
        disc(s, 25, 16, 2, tr, tg, tb, 255);
        disc(s, 25, 16, 1, 90, 85, 75, 255);
        fill_rect(s, 26, 20, 3, 2, 40, 38, 32, 255); /* exhaust */
        fill_rect(s, 27, 19, 2, 1, 70, 65, 55, 255);
        disc(s, 4, 11, 2, 220, 200, 80, 255); /* headlight L */
        disc(s, 4, 19, 2, 220, 200, 80, 255); /* headlight R */
        disc(s, 8, 7, 5, ok, og, ob, 255);
        disc(s, 22, 7, 5, ok, og, ob, 255);
        disc(s, 8, 23, 5, ok, og, ob, 255);
        disc(s, 22, 23, 5, ok, og, ob, 255);
        disc(s, 8, 7, 4, tr, tg, tb, 255);
        disc(s, 22, 7, 4, tr, tg, tb, 255);
        disc(s, 8, 23, 4, tr, tg, tb, 255);
        disc(s, 22, 23, 4, tr, tg, tb, 255);
        disc(s, 8, 7, 2, 90, 85, 75, 255);
        disc(s, 22, 7, 2, 90, 85, 75, 255);
        disc(s, 8, 23, 2, 90, 85, 75, 255);
        disc(s, 22, 23, 2, 90, 85, 75, 255);
        line(s, 15, 14, 29, 14, 40, 36, 30, 255);
        line(s, 15, 15, 29, 15, 50, 45, 35, 255);
        line(s, 15, 16, 29, 16, 40, 36, 30, 255);
        disc(s, 29, 15, 2, 60, 55, 45, 255);
        break;
    case UT_TANK:
        /* skirts + road wheels + glacis + mantlet + coax + exhaust + antenna + barrel */
        fill_rect(s, 2, 8, 5, 12, ok, og, ob, 255);
        fill_rect(s, 23, 8, 5, 12, ok, og, ob, 255);
        fill_rect(s, 3, 10, 3, 10, tr, tg, tb, 255);
        fill_rect(s, 24, 10, 3, 10, tr, tg, tb, 255);
        fill_rect(s, 2, 9, 5, 2, 50, 46, 40, 255); /* side skirt L top */
        fill_rect(s, 23, 9, 5, 2, 50, 46, 40, 255); /* side skirt R top */
        fill_rect(s, 2, 18, 5, 2, 50, 46, 40, 255); /* side skirt L bot */
        fill_rect(s, 23, 18, 5, 2, 50, 46, 40, 255);
        disc(s, 5, 11, 2, 40, 38, 32, 255); /* sprocket */
        disc(s, 5, 15, 2, 40, 38, 32, 255); /* road wheel */
        disc(s, 5, 20, 2, 40, 38, 32, 255);
        disc(s, 26, 11, 2, 40, 38, 32, 255);
        disc(s, 26, 15, 2, 40, 38, 32, 255);
        disc(s, 26, 20, 2, 40, 38, 32, 255);
        fill_rect(s, 4, 10, 22, 10, ok, og, ob, 255);
        fill_rect(s, 6, 11, 18, 8, base.r, base.g, base.b, 255);
        fill_rect(s, 5, 10, 8, 3, 55, 50, 42, 255); /* glacis plate */
        fill_rect(s, 6, 11, 6, 2, lite.r, lite.g, lite.b, 255);
        disc(s, 15, 15, 7, ok, og, ob, 255);
        disc(s, 15, 15, 6, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 18, 13, 4, 5, 45, 42, 36, 255); /* mantlet */
        fill_rect(s, 19, 14, 2, 3, 60, 55, 45, 255);
        disc(s, 15, 12, 2, 40, 38, 32, 255); /* hatch */
        line(s, 14, 12, 14, 2, 50, 46, 40, 255); /* antenna */
        line(s, 15, 12, 15, 1, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 7, 20, 3, 2, 40, 38, 32, 255); /* exhaust */
        fill_rect(s, 8, 19, 1, 1, 70, 65, 55, 255);
        line(s, 15, 13, 29, 13, 45, 40, 32, 255);
        line(s, 15, 14, 29, 14, 50, 45, 35, 255);
        line(s, 15, 15, 29, 15, 55, 50, 40, 255);
        line(s, 15, 16, 29, 16, 50, 45, 35, 255);
        line(s, 15, 17, 28, 17, 45, 40, 32, 255);
        line(s, 18, 12, 27, 11, 40, 36, 30, 255); /* coax MG */
        line(s, 18, 12, 27, 12, 50, 45, 35, 255);
        disc(s, 29, 15, 2, 60, 55, 45, 255);
        disc(s, 8, 23, 4, tr, tg, tb, 255);
        disc(s, 22, 23, 4, tr, tg, tb, 255);
        break;
    case UT_ARTILLERY:
        /* howitzer: outriggers + shield + ammo rack + elevated tube + brake */
        fill_rect(s, 1, 18, 8, 3, ok, og, ob, 255);   /* left outrigger */
        fill_rect(s, 21, 18, 8, 3, ok, og, ob, 255);  /* right outrigger */
        fill_rect(s, 0, 19, 4, 2, 40, 38, 32, 255);
        fill_rect(s, 26, 19, 4, 2, 40, 38, 32, 255);
        fill_rect(s, 4, 11, 22, 10, ok, og, ob, 255);
        fill_rect(s, 6, 13, 18, 7, base.r, base.g, base.b, 255);
        fill_rect(s, 22, 12, 6, 8, 55, 50, 40, 255); /* ammo rack */
        line(s, 23, 13, 27, 13, 90, 80, 55, 255);
        line(s, 23, 15, 27, 15, 90, 80, 55, 255);
        line(s, 23, 17, 27, 17, 90, 80, 55, 255);
        fill_rect(s, 10, 8, 10, 5, ok, og, ob, 255); /* gun shield */
        fill_rect(s, 11, 9, 8, 3, lite.r, lite.g, lite.b, 255);
        disc(s, 15, 14, 4, ok, og, ob, 255);
        disc(s, 15, 14, 3, lite.r, lite.g, lite.b, 255);
        line(s, 15, 11, 3, 1, 45, 40, 32, 255); /* elevated tube */
        line(s, 15, 12, 3, 2, 50, 45, 35, 255);
        line(s, 15, 13, 2, 1, 55, 50, 40, 255);
        line(s, 15, 14, 3, 3, 50, 45, 35, 255);
        line(s, 15, 15, 4, 4, 45, 40, 32, 255);
        fill_rect(s, 1, 0, 5, 4, 60, 55, 45, 255); /* muzzle brake */
        fill_rect(s, 2, 1, 3, 2, 30, 28, 24, 255);
        disc(s, 8, 23, 4, tr, tg, tb, 255);
        disc(s, 22, 23, 4, tr, tg, tb, 255);
        break;
    case UT_HARVESTER:
        /* cabin + boom/scoop + conveyor + hopper panels + exhaust/lights + hubbed wheels */
        fill_rect(s, 1, 6, 28, 18, ok, og, ob, 255);
        fill_rect(s, 3, 8, 24, 14, base.r, base.g, base.b, 255);
        fill_rect(s, 3, 8, 8, 8, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 4, 8, 6, 3, 35, 55, 75, 255); /* glass */
        fill_rect(s, 5, 12, 4, 2, 45, 42, 36, 255); /* cabin panel */
        line(s, 2, 14, 8, 11, 50, 46, 40, 255); /* boom arm */
        line(s, 2, 15, 8, 12, 70, 65, 55, 255);
        fill_rect(s, 0, 14, 5, 5, 90, 80, 55, 255); /* scoop lip */
        fill_rect(s, 1, 15, 3, 3, 70, 60, 40, 255);
        fill_rect(s, 11, 10, 14, 10, 55, 48, 32, 255); /* hopper bed */
        fill_rect(s, 11, 10, 8, 10, 200, 170, 90, 255);
        line(s, 14, 10, 24, 10, 160, 130, 70, 255); /* conveyor ribs */
        line(s, 14, 13, 24, 13, 160, 130, 70, 255);
        line(s, 14, 16, 24, 16, 160, 130, 70, 255);
        fill_rect(s, 12, 9, 12, 1, 45, 40, 32, 255); /* hopper rim */
        fill_rect(s, 24, 11, 3, 8, 50, 46, 40, 255); /* side panel */
        fill_rect(s, 25, 12, 1, 6, 70, 65, 55, 255);
        fill_rect(s, 20, 18, 4, 2, 40, 38, 32, 255); /* exhaust */
        fill_rect(s, 21, 17, 2, 1, 70, 65, 55, 255);
        disc(s, 4, 10, 2, 220, 200, 80, 255); /* cabin light */
        disc(s, 2, 16, 1, 220, 180, 60, 255); /* scoop lamp */
        disc(s, 8, 23, 5, ok, og, ob, 255);
        disc(s, 22, 23, 5, ok, og, ob, 255);
        disc(s, 8, 23, 4, tr, tg, tb, 255);
        disc(s, 22, 23, 4, tr, tg, tb, 255);
        disc(s, 8, 23, 2, 90, 85, 75, 255);
        disc(s, 22, 23, 2, 90, 85, 75, 255);
        line(s, 5, 7, 5, 2, lite.r, lite.g, lite.b, 255);
        line(s, 6, 7, 6, 3, 50, 46, 40, 255);
        break;
    case UT_JEEP:
        /* bumper + grill + seats + jerry cans + spare + lights + antenna + cage + MG */
        fill_rect(s, 4, 9, 22, 12, ok, og, ob, 255);
        fill_rect(s, 6, 11, 18, 8, base.r, base.g, base.b, 255);
        fill_rect(s, 3, 12, 3, 6, 55, 50, 40, 255); /* bumper */
        fill_rect(s, 4, 13, 1, 4, 90, 80, 55, 255);
        fill_rect(s, 5, 13, 3, 4, 40, 38, 32, 255); /* grill */
        line(s, 5, 14, 7, 14, 70, 65, 55, 255);
        line(s, 5, 16, 7, 16, 70, 65, 55, 255);
        fill_rect(s, 7, 10, 8, 5, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 8, 12, 3, 3, 45, 40, 35, 255); /* seat L */
        fill_rect(s, 14, 12, 3, 3, 45, 40, 35, 255); /* seat R */
        fill_rect(s, 22, 11, 3, 4, 70, 90, 50, 255); /* jerry can */
        fill_rect(s, 23, 12, 1, 2, 90, 110, 60, 255);
        disc(s, 24, 18, 3, ok, og, ob, 255); /* spare */
        disc(s, 24, 18, 2, tr, tg, tb, 255);
        disc(s, 24, 18, 1, 90, 85, 75, 255);
        disc(s, 5, 11, 2, 220, 200, 80, 255); /* light L */
        disc(s, 5, 19, 2, 220, 200, 80, 255); /* light R */
        line(s, 16, 10, 16, 1, 50, 46, 40, 255); /* antenna */
        line(s, 17, 10, 17, 2, lite.r, lite.g, lite.b, 255);
        disc(s, 9, 22, 5, ok, og, ob, 255);
        disc(s, 21, 22, 5, ok, og, ob, 255);
        disc(s, 9, 22, 4, tr, tg, tb, 255);
        disc(s, 21, 22, 4, tr, tg, tb, 255);
        disc(s, 9, 22, 2, 90, 85, 75, 255);
        disc(s, 21, 22, 2, 90, 85, 75, 255);
        line(s, 11, 11, 11, 3, lite.r, lite.g, lite.b, 255);
        line(s, 12, 11, 12, 3, 50, 46, 40, 255);
        line(s, 19, 11, 19, 3, lite.r, lite.g, lite.b, 255);
        line(s, 18, 11, 18, 3, 50, 46, 40, 255);
        line(s, 11, 3, 19, 3, lite.r, lite.g, lite.b, 255);
        line(s, 11, 4, 19, 4, 50, 46, 40, 255);
        line(s, 15, 14, 28, 14, 40, 36, 30, 255);
        line(s, 15, 15, 28, 15, 50, 45, 35, 255);
        line(s, 15, 16, 28, 16, 40, 36, 30, 255);
        disc(s, 28, 15, 2, 60, 55, 45, 255);
        break;
    case UT_MUTANT:
        /* plates + eyes/jaw + spikes + dual claws + tail */
        disc(s, 15, 17, 11, ok, og, ob, 255);
        disc(s, 15, 15, 9, base.r, base.g, base.b, 255);
        fill_rect(s, 10, 14, 4, 3, 45, 40, 35, 255); /* chest plate L */
        fill_rect(s, 17, 14, 4, 3, 45, 40, 35, 255); /* chest plate R */
        disc(s, 15, 9, 5, ok, og, ob, 255);
        disc(s, 15, 9, 4, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 11, 7, 7, 2, 30, 40, 50, 255); /* brow */
        disc(s, 12, 9, 1, 200, 60, 40, 255); /* eye L */
        disc(s, 18, 9, 1, 200, 60, 40, 255); /* eye R */
        fill_rect(s, 13, 11, 5, 2, 40, 30, 28, 255); /* jaw */
        line(s, 14, 12, 14, 13, 70, 55, 45, 255); /* fang */
        line(s, 16, 12, 16, 13, 70, 55, 45, 255);
        line(s, 12, 6, 9, 0, 40, 36, 30, 255);
        line(s, 13, 6, 10, 1, 55, 50, 40, 255);
        line(s, 15, 5, 15, 0, 40, 36, 30, 255);
        line(s, 16, 5, 16, 0, 55, 50, 40, 255);
        line(s, 18, 6, 21, 0, 40, 36, 30, 255);
        line(s, 17, 6, 20, 1, 55, 50, 40, 255);
        line(s, 14, 4, 12, 0, 50, 45, 35, 255); /* extra spike */
        line(s, 15, 16, 26, 8, 40, 36, 30, 255);
        line(s, 15, 17, 26, 9, 50, 45, 35, 255);
        line(s, 24, 9, 29, 5, 55, 50, 40, 255);
        line(s, 24, 9, 29, 11, 55, 50, 40, 255);
        line(s, 24, 10, 28, 8, 70, 60, 45, 255);
        disc(s, 28, 8, 2, 70, 60, 45, 255); /* claw tip R */
        line(s, 12, 16, 4, 10, 40, 36, 30, 255); /* second claw L */
        line(s, 12, 17, 4, 11, 50, 45, 35, 255);
        line(s, 5, 10, 1, 7, 55, 50, 40, 255);
        line(s, 5, 11, 1, 13, 55, 50, 40, 255);
        disc(s, 2, 10, 2, 70, 60, 45, 255);
        line(s, 15, 20, 15, 27, 45, 40, 35, 255); /* tail */
        line(s, 16, 20, 18, 28, 55, 50, 40, 255);
        disc(s, 17, 27, 2, 60, 50, 40, 255);
        disc(s, 10, 22, 4, ok, og, ob, 255);
        disc(s, 20, 22, 4, ok, og, ob, 255);
        disc(s, 10, 22, 3, base.r, base.g, base.b, 255);
        disc(s, 20, 22, 3, base.r, base.g, base.b, 255);
        break;
    case UT_BEAST:
        /* carapace plates/spines + eye + vents + tusks + hubbed multi-wheel */
        fill_rect(s, 5, 9, 20, 12, ok, og, ob, 255);
        fill_rect(s, 7, 11, 16, 8, base.r, base.g, base.b, 255);
        fill_rect(s, 9, 10, 12, 3, lite.r, lite.g, lite.b, 255); /* carapace ridge */
        fill_rect(s, 8, 13, 5, 3, 50, 46, 40, 255); /* plate L */
        fill_rect(s, 17, 13, 5, 3, 50, 46, 40, 255); /* plate R */
        line(s, 10, 9, 10, 5, 40, 36, 30, 255); /* spine */
        line(s, 13, 9, 13, 4, 55, 50, 40, 255);
        line(s, 16, 9, 16, 4, 55, 50, 40, 255);
        line(s, 19, 9, 19, 5, 40, 36, 30, 255);
        fill_rect(s, 11, 16, 2, 2, 30, 28, 24, 255); /* vent L */
        fill_rect(s, 17, 16, 2, 2, 30, 28, 24, 255); /* vent R */
        disc(s, 9, 21, 4, ok, og, ob, 255);
        disc(s, 14, 22, 4, ok, og, ob, 255);
        disc(s, 19, 21, 4, ok, og, ob, 255);
        disc(s, 23, 22, 4, ok, og, ob, 255);
        disc(s, 9, 21, 3, tr, tg, tb, 255);
        disc(s, 14, 22, 3, tr, tg, tb, 255);
        disc(s, 19, 21, 3, tr, tg, tb, 255);
        disc(s, 23, 22, 3, tr, tg, tb, 255);
        disc(s, 9, 21, 1, 90, 85, 75, 255); /* hub */
        disc(s, 14, 22, 1, 90, 85, 75, 255);
        disc(s, 19, 21, 1, 90, 85, 75, 255);
        disc(s, 23, 22, 1, 90, 85, 75, 255);
        disc(s, 24, 12, 6, ok, og, ob, 255);
        disc(s, 24, 12, 5, lite.r, lite.g, lite.b, 255); /* snout */
        disc(s, 26, 11, 1, 200, 80, 40, 255); /* eye */
        line(s, 26, 10, 29, 8, 40, 36, 30, 255); /* tusk */
        line(s, 26, 14, 29, 16, 40, 36, 30, 255);
        line(s, 26, 12, 29, 12, 55, 50, 40, 255);
        disc(s, 29, 12, 2, 60, 55, 45, 255);
        break;
    case UT_RAVAGER:
        /* prow + ammo boxes + triple gatling + exhaust (vs tank cupola) */
        fill_rect(s, 0, 7, 5, 14, ok, og, ob, 255);
        fill_rect(s, 25, 7, 5, 14, ok, og, ob, 255);
        fill_rect(s, 1, 10, 3, 10, tr, tg, tb, 255);
        fill_rect(s, 26, 10, 3, 10, tr, tg, tb, 255);
        disc(s, 3, 12, 2, 40, 38, 32, 255);
        disc(s, 3, 20, 2, 40, 38, 32, 255);
        disc(s, 28, 12, 2, 40, 38, 32, 255);
        disc(s, 28, 20, 2, 40, 38, 32, 255);
        fill_rect(s, 3, 9, 24, 12, ok, og, ob, 255);
        fill_rect(s, 5, 10, 20, 10, base.r, base.g, base.b, 255);
        fill_rect(s, 24, 8, 6, 6, 55, 48, 38, 255); /* prow plate */
        line(s, 25, 9, 29, 11, 70, 60, 45, 255);
        line(s, 25, 13, 29, 11, 70, 60, 45, 255);
        fill_rect(s, 4, 8, 5, 4, 70, 55, 35, 255); /* ammo boxes */
        fill_rect(s, 5, 9, 3, 2, 200, 160, 60, 255);
        fill_rect(s, 10, 8, 5, 4, 70, 55, 35, 255);
        fill_rect(s, 11, 9, 3, 2, 200, 160, 60, 255);
        fill_rect(s, 12, 12, 10, 8, ok, og, ob, 255); /* gatling block */
        fill_rect(s, 13, 13, 8, 6, lite.r, lite.g, lite.b, 255);
        line(s, 20, 13, 29, 12, 45, 40, 32, 255); /* triple barrels */
        line(s, 20, 15, 29, 15, 55, 50, 40, 255);
        line(s, 20, 17, 29, 18, 45, 40, 32, 255);
        disc(s, 29, 12, 1, 60, 55, 45, 255);
        disc(s, 29, 15, 2, 60, 55, 45, 255);
        disc(s, 29, 18, 1, 60, 55, 45, 255);
        fill_rect(s, 2, 14, 3, 4, 40, 38, 32, 255); /* exhaust */
        disc(s, 2, 15, 2, 90, 70, 40, 255);
        disc(s, 2, 17, 1, 200, 100, 40, 255);
        disc(s, 7, 23, 5, ok, og, ob, 255);
        disc(s, 23, 23, 5, ok, og, ob, 255);
        disc(s, 7, 23, 4, tr, tg, tb, 255);
        disc(s, 23, 23, 4, tr, tg, tb, 255);
        break;
    case UT_FLAME:
        /* dual tanks + hose + heat shield + nozzle jet */
        fill_rect(s, 7, 12, 16, 12, ok, og, ob, 255);
        fill_rect(s, 9, 14, 12, 9, base.r, base.g, base.b, 255);
        disc(s, 15, 9, 5, ok, og, ob, 255);
        disc(s, 15, 9, 4, lite.r, lite.g, lite.b, 255);
        fill_rect(s, 12, 8, 5, 2, 30, 40, 50, 255); /* visor */
        disc(s, 6, 13, 5, ok, og, ob, 255); /* dual fuel tanks */
        disc(s, 6, 13, 4, 90, 70, 40, 255);
        disc(s, 6, 13, 2, 200, 120, 40, 255);
        disc(s, 6, 19, 5, ok, og, ob, 255);
        disc(s, 6, 19, 4, 90, 70, 40, 255);
        disc(s, 6, 19, 2, 200, 120, 40, 255);
        disc(s, 6, 11, 1, 60, 55, 45, 255);
        disc(s, 6, 17, 1, 60, 55, 45, 255);
        disc(s, 6, 21, 1, 60, 55, 45, 255);
        line(s, 10, 14, 16, 16, 50, 45, 35, 255); /* hose */
        line(s, 10, 15, 16, 17, 70, 55, 35, 255);
        fill_rect(s, 16, 12, 5, 8, 55, 50, 40, 255); /* heat shield */
        fill_rect(s, 17, 13, 3, 6, 90, 70, 40, 255);
        line(s, 20, 14, 28, 19, 255, 120, 40, 255);
        line(s, 20, 15, 28, 20, 255, 150, 50, 255);
        line(s, 20, 16, 27, 21, 255, 180, 60, 255);
        line(s, 20, 17, 26, 21, 255, 200, 80, 255);
        disc(s, 28, 20, 3, 255, 200, 80, 255);
        disc(s, 28, 20, 1, 255, 240, 160, 255);
        break;
    case UT_MISSILE:
        /* MLRS box launcher + rails + warning stripes + hubbed chassis */
        fill_rect(s, 3, 12, 24, 12, ok, og, ob, 255);
        fill_rect(s, 5, 14, 20, 8, base.r, base.g, base.b, 255);
        fill_rect(s, 8, 4, 16, 10, ok, og, ob, 255); /* box launcher */
        fill_rect(s, 9, 5, 14, 8, 50, 48, 42, 255);
        line(s, 10, 6, 22, 6, 90, 85, 70, 255); /* rails */
        line(s, 10, 8, 22, 8, 90, 85, 70, 255);
        line(s, 10, 10, 22, 10, 90, 85, 70, 255);
        line(s, 10, 12, 22, 12, 90, 85, 70, 255);
        fill_rect(s, 9, 5, 3, 8, 255, 200, 40, 255); /* warning stripes */
        fill_rect(s, 12, 5, 2, 8, 30, 28, 24, 255);
        fill_rect(s, 14, 5, 3, 8, 255, 200, 40, 255);
        disc(s, 23, 7, 2, 255, 120, 80, 255); /* nose tips */
        disc(s, 23, 10, 2, 255, 140, 90, 255);
        disc(s, 9, 23, 5, ok, og, ob, 255);
        disc(s, 21, 23, 5, ok, og, ob, 255);
        disc(s, 9, 23, 4, tr, tg, tb, 255);
        disc(s, 21, 23, 4, tr, tg, tb, 255);
        disc(s, 9, 23, 2, 90, 85, 75, 255);
        disc(s, 21, 23, 2, 90, 85, 75, 255);
        line(s, 22, 8, 29, 4, 255, 80, 60, 255);
        line(s, 22, 10, 29, 6, 255, 100, 70, 255);
        disc(s, 29, 5, 2, 255, 140, 90, 255);
        break;
    case UT_MEDIC:
        /* white van + light bar + bold red cross + hubs (read at live scale) */
        fill_rect(s, 3, 9, 24, 17, ok, og, ob, 255);
        fill_rect(s, 5, 11, 20, 13, 245, 245, 245, 255);
        fill_rect(s, 6, 12, 18, 11, 255, 255, 255, 255);
        fill_rect(s, 5, 8, 7, 5, 190, 215, 235, 255); /* cab glass */
        fill_rect(s, 8, 3, 14, 3, 240, 40, 40, 255);   /* light bar */
        fill_rect(s, 10, 2, 10, 2, 255, 80, 80, 255);
        disc(s, 9, 24, 5, ok, og, ob, 255);
        disc(s, 21, 24, 5, ok, og, ob, 255);
        disc(s, 9, 24, 4, tr, tg, tb, 255);
        disc(s, 21, 24, 4, tr, tg, tb, 255);
        disc(s, 9, 24, 2, 90, 85, 75, 255);
        disc(s, 21, 24, 2, 90, 85, 75, 255);
        disc(s, 15, 10, 7, 230, 35, 35, 255);
        fill_rect(s, 13, 4, 4, 12, 255, 255, 255, 255);
        fill_rect(s, 9, 8, 12, 4, 255, 255, 255, 255);
        break;
    default:
        disc(s, 15, 15, 10, ok, og, ob, 255);
        disc(s, 15, 15, 8, base.r, base.g, base.b, 255);
        break;
    }
    SDL_Texture *tex = SDL_CreateTextureFromSurface(r, s);
    SDL_FreeSurface(s);
    return tex;
}

/* ---------------- building sprites ---------------- */
/* Bright concrete pad + BT_* interiors (parity with snapshot draw_bld). */
SDL_Texture *sprites_make_bld(SDL_Renderer *r, BuildingType t, Faction f) {
    int w = bld_def(t)->w, h = bld_def(t)->h;
    int W = w * TILE, H = h * TILE;
    SDL_Surface *s = new_surf(W, H);
    SDL_Color base = faction_color(f);
    SDL_Color dark = darken(base, 0.5f);
    SDL_Color lite = lighten(base, 0.35f);
    const Uint8 ok = 22, og = 20, ob = 16;
    const Uint8 wall = 205, wall2 = 175;

    /* Bright concrete pad on arid sand */
    fill_rect(s, 0, 0, W, H, ok, og, ob, 255);
    fill_rect(s, 2, 2, W - 4, H - 4, 210, 185, 130, 255);
    fill_rect(s, 4, 4, W - 8, H - 8, wall2, (Uint8)(wall2 - 18), (Uint8)(wall2 - 45), 255);
    fill_rect(s, 5, 5, W - 10, H - 10, wall, (Uint8)(wall - 22), (Uint8)(wall - 55), 255);
    fill_rect(s, 5, 5, W - 10, 6, (Uint8)(wall + 30), (Uint8)(wall + 10), (Uint8)(wall - 20), 255);

    switch (t) {
    case BT_BASE:
        if (f == FACTION_EVOLVED) {
            /* hive: lobes + membrane ridges + spine + pit eye (KKND HQ read) */
            disc(s, 14, 18, 14, ok, og, ob, 255);
            disc(s, 14, 18, 12, base.r, base.g, base.b, 255);
            disc(s, W - 14, 18, 14, ok, og, ob, 255);
            disc(s, W - 14, 18, 12, base.r, base.g, base.b, 255);
            disc(s, 16, H - 16, 12, ok, og, ob, 255);
            disc(s, 16, H - 16, 10, base.r, base.g, base.b, 255);
            disc(s, W - 16, H - 16, 12, ok, og, ob, 255);
            disc(s, W - 16, H - 16, 10, base.r, base.g, base.b, 255);
            disc(s, W/2, H/2, 16, ok, og, ob, 255);
            disc(s, W/2, H/2, 14, base.r, base.g, base.b, 255);
            /* membrane ridges between lobes */
            line(s, 18, 20, W/2 - 8, H/2 - 4, ok, og, ob, 255);
            line(s, W - 18, 20, W/2 + 8, H/2 - 4, ok, og, ob, 255);
            line(s, 18, H - 18, W/2 - 6, H/2 + 6, ok, og, ob, 255);
            line(s, W - 18, H - 18, W/2 + 6, H/2 + 6, ok, og, ob, 255);
            /* dorsal spine + tendrils */
            fill_rect(s, W/2 - 2, 4, 4, H/2 - 8, ok, og, ob, 255);
            fill_rect(s, W/2 - 1, 5, 2, H/2 - 10, 90, 40, 55, 255);
            line(s, W/2, 8, W/2 - 10, 18, 70, 30, 45, 255);
            line(s, W/2, 8, W/2 + 10, 18, 70, 30, 45, 255);
            /* dark pit + glowing eye */
            disc(s, W/2, H/2, 8, 28, 18, 22, 255);
            disc(s, W/2, H/2, 5, 60, 20, 30, 255);
            disc(s, W/2, H/2, 3, 220, 60, 90, 255);
            disc(s, W/2, H/2, 1, 255, 180, 200, 255);
            ring(s, W/2, H/2, 10, 2, 50, 25, 35, 255); /* pit rim */
            /* extra blisters */
            disc(s, W/2 - 10, 10, 5, lite.r, lite.g, lite.b, 255);
            disc(s, W/2 + 12, H - 12, 4, lite.r, lite.g, lite.b, 255);
            disc(s, 10, H/2 + 2, 3, lite.r, lite.g, lite.b, 255);
            disc(s, W - 10, H/2 - 4, 3, lite.r, lite.g, lite.b, 255);
            disc(s, W/2 + 8, 14, 2, 180, 70, 100, 255);
        } else {
            /* Survivors HQ: towers + walkways + dome + dish + entry (KKND HQ read) */
            fill_rect(s, 4, 4, 14, 14, ok, og, ob, 255);
            fill_rect(s, 6, 6, 10, 10, base.r, base.g, base.b, 255);
            fill_rect(s, W - 18, 4, 14, 14, ok, og, ob, 255);
            fill_rect(s, W - 16, 6, 10, 10, base.r, base.g, base.b, 255);
            fill_rect(s, 4, H - 18, 14, 14, ok, og, ob, 255);
            fill_rect(s, 6, H - 16, 10, 10, base.r, base.g, base.b, 255);
            fill_rect(s, W - 18, H - 18, 14, 14, ok, og, ob, 255);
            fill_rect(s, W - 16, H - 16, 10, 10, base.r, base.g, base.b, 255);
            /* tower windows + corner lights */
            fill_rect(s, 8, 8, 3, 3, 200, 230, 255, 255);
            fill_rect(s, W - 13, 8, 3, 3, 200, 230, 255, 255);
            fill_rect(s, 8, H - 13, 3, 3, 200, 230, 255, 255);
            fill_rect(s, W - 13, H - 13, 3, 3, 200, 230, 255, 255);
            disc(s, 7, 5, 2, 255, 220, 80, 255);
            disc(s, W - 7, 5, 2, 255, 220, 80, 255);
            /* courtyard body + roof band */
            fill_rect(s, 14, 14, W - 28, H - 28, ok, og, ob, 255);
            fill_rect(s, 16, 16, W - 32, H - 32, base.r, base.g, base.b, 255);
            fill_rect(s, 18, 18, W - 36, 8, lite.r, lite.g, lite.b, 255);
            /* walkways between towers */
            fill_rect(s, 16, 8, W - 32, 3, 90, 85, 70, 255);
            fill_rect(s, 16, H - 11, W - 32, 3, 90, 85, 70, 255);
            fill_rect(s, 8, 16, 3, H - 32, 90, 85, 70, 255);
            fill_rect(s, W - 11, 16, 3, H - 32, 90, 85, 70, 255);
            /* command dome + mast + radar dish */
            disc(s, W/2, H/2 - 2, 10, ok, og, ob, 255);
            disc(s, W/2, H/2 - 2, 8, lite.r, lite.g, lite.b, 255);
            disc(s, W/2, H/2 - 2, 4, 255, 250, 180, 255);
            fill_rect(s, W/2 - 2, 2, 4, H/2 - 6, 200, 180, 60, 255);
            fill_rect(s, W/2 - 6, 2, 12, 3, 220, 210, 80, 255);
            disc(s, W/2 + 8, 8, 5, ok, og, ob, 255); /* dish */
            disc(s, W/2 + 8, 8, 3, 180, 200, 220, 255);
            line(s, W/2 + 2, 6, W/2 + 8, 8, 160, 150, 100, 255);
            /* entry bunker + blast doors */
            fill_rect(s, W/2 - 8, H - 14, 16, 8, ok, og, ob, 255);
            fill_rect(s, W/2 - 6, H - 12, 12, 6, 40, 38, 34, 255);
            fill_rect(s, W/2 - 4, H - 11, 3, 4, 70, 65, 55, 255);
            fill_rect(s, W/2 + 1, H - 11, 3, 4, 70, 65, 55, 255);
            /* side annex slits */
            fill_rect(s, 18, H/2 + 2, 6, 4, 160, 200, 230, 255);
            fill_rect(s, W - 24, H/2 + 2, 6, 4, 160, 200, 230, 255);
        }
        break;
    case BT_WARFACTORY:
        /* hangar + crane mast/jib + segmented bay doors (KKND factory read) */
        fill_rect(s, 4, 6, W - 8, H - 12, ok, og, ob, 255);
        fill_rect(s, 6, 8, W - 12, H - 16, base.r, base.g, base.b, 255);
        fill_rect(s, 8, 10, W - 16, 12, lite.r, lite.g, lite.b, 255); /* roof ridge */
        fill_rect(s, 10, 12, 5, 5, 55, 50, 42, 255); /* ridge vents */
        fill_rect(s, W/2 - 8, 12, 5, 5, 55, 50, 42, 255);
        fill_rect(s, W/2 + 3, 12, 5, 5, 55, 50, 42, 255);
        fill_rect(s, W - 15, 12, 5, 5, 55, 50, 42, 255);
        /* side workshop annex */
        fill_rect(s, 4, H/2 - 4, 10, H/2 - 6, ok, og, ob, 255);
        fill_rect(s, 5, H/2 - 2, 8, H/2 - 10, dark.r, dark.g, dark.b, 255);
        fill_rect(s, 6, H/2, 6, 4, 90, 80, 55, 255); /* window slit */
        /* overhead crane mast + jib */
        fill_rect(s, W - 14, 4, 6, H - 18, ok, og, ob, 255);
        fill_rect(s, W - 13, 5, 4, H - 20, 95, 88, 70, 255);
        fill_rect(s, 14, 6, W - 28, 4, ok, og, ob, 255);
        fill_rect(s, 15, 7, W - 30, 2, 120, 110, 85, 255);
        line(s, 18, 10, 18, 22, 70, 65, 50, 255);
        disc(s, 18, 24, 3, 80, 75, 55, 255); /* hoist block */
        /* segmented bay doors */
        fill_rect(s, 12, H - 30, W - 28, 20, ok, og, ob, 255);
        fill_rect(s, 14, H - 28, W - 32, 16, 32, 32, 38, 255);
        line(s, W/2 - 6, H - 28, W/2 - 6, H - 12, 70, 68, 60, 255);
        line(s, W/2, H - 28, W/2, H - 12, 70, 68, 60, 255);
        line(s, W/2 + 6, H - 28, W/2 + 6, H - 12, 70, 68, 60, 255);
        line(s, 14, H - 20, W - 18, H - 20, 55, 52, 48, 255);
        fill_rect(s, 10, H - 10, W - 20, 5, 50, 48, 42, 255); /* ramp lip */
        fill_rect(s, 12, H - 9, W - 24, 2, 90, 75, 45, 255);
        break;
    case BT_REFINERY:
        /* oil-field: derrick + pumpjack + twin tanks + pipes + hopper (KKND read) */
        fill_rect(s, 4, H - 12, W - 8, 10, ok, og, ob, 255); /* slab */
        fill_rect(s, 6, H - 10, W - 12, 6, 70, 62, 48, 255);
        /* latticed derrick mast */
        fill_rect(s, W/2 - 3, 4, 6, H - 18, ok, og, ob, 255);
        fill_rect(s, W/2 - 2, 5, 4, H - 20, 95, 85, 65, 255);
        line(s, W/2 - 6, 10, W/2 + 6, 22, 55, 48, 38, 255);
        line(s, W/2 + 6, 10, W/2 - 6, 22, 55, 48, 38, 255);
        line(s, W/2 - 6, 24, W/2 + 6, 36, 55, 48, 38, 255);
        line(s, W/2 + 6, 24, W/2 - 6, 36, 55, 48, 38, 255);
        line(s, W/2 - 6, 38, W/2 + 6, H - 18, 55, 48, 38, 255);
        line(s, W/2 + 6, 38, W/2 - 6, H - 18, 55, 48, 38, 255);
        line(s, W/2 - 5, 8, W/2 - 5, H - 16, 40, 36, 30, 255);
        line(s, W/2 + 5, 8, W/2 + 5, H - 16, 40, 36, 30, 255);
        fill_rect(s, W/2 - 7, 2, 14, 5, ok, og, ob, 255); /* crown */
        fill_rect(s, W/2 - 5, 3, 10, 3, 200, 170, 80, 255); /* beacon */
        /* pumpjack horse-head (left of mast) */
        fill_rect(s, 8, H/2 - 2, 4, H/2 - 8, ok, og, ob, 255);
        fill_rect(s, 9, H/2, 2, H/2 - 12, 90, 80, 60, 255);
        fill_rect(s, 6, H/2 - 6, 14, 4, ok, og, ob, 255);
        fill_rect(s, 7, H/2 - 5, 12, 2, 110, 95, 70, 255);
        disc(s, 8, H/2 - 8, 4, ok, og, ob, 255); /* horse head */
        disc(s, 8, H/2 - 8, 2, 130, 110, 80, 255);
        line(s, 10, H/2 - 4, W/2 - 4, 16, 80, 70, 50, 255); /* bridle cable */
        /* gantry arm + walkway toward hopper */
        fill_rect(s, W/2 + 2, 14, W/2 - 10, 4, ok, og, ob, 255);
        fill_rect(s, W/2 + 3, 15, W/2 - 12, 2, 120, 100, 60, 255);
        fill_rect(s, W/2 + 4, 18, W/2 - 16, 2, 70, 60, 45, 255); /* catwalk */
        line(s, W/2 + 4, 18, W - 12, H - 22, 90, 75, 50, 255);
        /* hopper / processing shed + windows */
        fill_rect(s, W - 24, H - 32, 18, 18, ok, og, ob, 255);
        fill_rect(s, W - 22, H - 30, 14, 14, base.r, base.g, base.b, 255);
        fill_rect(s, W - 20, H - 28, 10, 6, 140, 110, 55, 255);
        fill_rect(s, W - 18, H - 26, 3, 3, 180, 220, 255, 255); /* window */
        fill_rect(s, W - 13, H - 26, 3, 3, 180, 220, 255, 255);
        fill_rect(s, W - 16, H - 18, 4, 4, 40, 36, 30, 255); /* chute */
        /* twin scrap tanks */
        disc(s, 14, H - 18, 9, ok, og, ob, 255);
        disc(s, 14, H - 18, 7, 200, 165, 85, 255);
        ring(s, 14, H - 18, 4, 2, 90, 70, 45, 255);
        disc(s, 28, H - 16, 7, ok, og, ob, 255);
        disc(s, 28, H - 16, 5, 180, 150, 75, 255);
        ring(s, 28, H - 16, 3, 1, 80, 60, 40, 255);
        /* pipe runs tank→mast→hopper */
        line(s, 20, H - 16, W/2 - 4, H - 12, 110, 90, 50, 255);
        line(s, 28, H - 14, W/2 - 2, H - 14, 100, 85, 45, 255);
        line(s, W/2 + 4, H - 14, W - 20, H - 20, 100, 85, 45, 255);
        fill_rect(s, W/2 - 1, H - 16, 3, 4, 80, 70, 50, 255); /* valve */
        /* oil stain pool under slab */
        disc(s, W/2 - 8, H - 6, 4, 40, 32, 20, 255);
        disc(s, W/2 + 6, H - 5, 3, 35, 28, 18, 255);
        break;
    case BT_POWER:
        /* tall cooling towers + reactor block + steam plumes (KKND plant read) */
        fill_rect(s, 3, H - 10, W - 6, 8, ok, og, ob, 255);
        fill_rect(s, 4, H - 8, W - 8, 5, 55, 50, 42, 255); /* pad */
        /* left cooling tower (taller cone) */
        fill_rect(s, 4, 8, 10, H - 18, ok, og, ob, 255);
        fill_rect(s, 5, 9, 8, H - 20, 95, 145, 195, 255);
        fill_rect(s, 6, 6, 6, 5, ok, og, ob, 255);
        fill_rect(s, 7, 5, 4, 4, 70, 120, 170, 255); /* rim */
        disc(s, 9, 4, 3, 240, 248, 255, 255); /* steam puff */
        disc(s, 7, 2, 2, 220, 235, 250, 255);
        /* right cooling tower */
        fill_rect(s, W - 14, 10, 10, H - 20, ok, og, ob, 255);
        fill_rect(s, W - 13, 11, 8, H - 22, 85, 135, 185, 255);
        fill_rect(s, W - 12, 8, 6, 4, ok, og, ob, 255);
        fill_rect(s, W - 11, 7, 4, 3, 65, 115, 165, 255);
        disc(s, W - 9, 5, 3, 235, 245, 255, 255);
        disc(s, W - 7, 3, 2, 210, 230, 250, 255);
        /* central reactor block + glow */
        fill_rect(s, W/2 - 5, H/2 - 4, 10, H/2 - 2, ok, og, ob, 255);
        fill_rect(s, W/2 - 4, H/2 - 2, 8, H/2 - 6, 55, 95, 150, 255);
        disc(s, W/2, H/2 + 2, 4, 120, 200, 255, 255);
        disc(s, W/2, H/2 + 2, 2, 250, 252, 255, 255);
        line(s, W/2, 8, W/2, H - 10, 200, 230, 250, 255);
        line(s, 8, H/2 + 2, W - 8, H/2 + 2, 180, 220, 245, 255);
        break;
    case BT_TURRET:
        /* armored bunker + ringed cupola + thick barrel (KKND turret read) */
        fill_rect(s, 2, H - 14, W - 4, 12, ok, og, ob, 255);
        fill_rect(s, 3, H - 12, W - 6, 9, 48, 44, 38, 255); /* bunker slab */
        fill_rect(s, 4, H - 11, 4, 4, 70, 65, 55, 255); /* armor plate L */
        fill_rect(s, W - 8, H - 11, 4, 4, 70, 65, 55, 255); /* armor plate R */
        fill_rect(s, W/2 - 5, H - 8, 10, 3, 35, 32, 28, 255); /* embrasure */
        /* ringed cupola */
        disc(s, W/2, H/2, W/3 + 3, ok, og, ob, 255);
        disc(s, W/2, H/2, W/3 + 1, base.r, base.g, base.b, 255);
        ring(s, W/2, H/2, W/4 + 1, 2, dark.r, dark.g, dark.b, 255);
        disc(s, W/2, H/2, W/5, lite.r, lite.g, lite.b, 255);
        disc(s, W/2, H/2 - 1, 3, 35, 32, 28, 255); /* hatch */
        /* thick armored barrel */
        fill_rect(s, W/2 + 2, H/2 - 3, 12, 5, ok, og, ob, 255);
        fill_rect(s, W/2 + 3, H/2 - 2, 11, 3, 40, 36, 30, 255);
        line(s, W/2, H/2, W/2 + 14, H/2 - 10, 28, 26, 22, 255);
        line(s, W/2 + 1, H/2 + 1, W/2 + 14, H/2 - 9, 55, 48, 38, 255);
        disc(s, W/2 + 13, H/2 - 10, 2, 255, 200, 80, 255); /* muzzle tip */
        break;
    case BT_WALL:
        /* thick fort wall + crenels + seams + embrasure (KKND fort read) */
        fill_rect(s, 0, 4, W, H - 4, ok, og, ob, 255);
        fill_rect(s, 1, 6, W - 2, H - 8, 165, 145, 110, 255);
        fill_rect(s, 2, H - 6, W - 4, 4, 90, 78, 58, 255); /* plinth */
        /* thick merlons */
        fill_rect(s, 1, 1, 8, 10, ok, og, ob, 255);
        fill_rect(s, 2, 2, 6, 8, 195, 175, 140, 255);
        fill_rect(s, W/2 - 4, 1, 8, 10, ok, og, ob, 255);
        fill_rect(s, W/2 - 3, 2, 6, 8, 200, 180, 145, 255);
        fill_rect(s, W - 9, 1, 8, 10, ok, og, ob, 255);
        fill_rect(s, W - 8, 2, 6, 8, 190, 170, 135, 255);
        fill_rect(s, 2, 10, W - 4, 3, 215, 195, 155, 255); /* coping */
        /* block seams + arrow slit */
        line(s, 2, H/2 + 2, W - 2, H/2 + 2, 55, 48, 38, 255);
        line(s, W/3, 8, W/3, H - 4, 65, 55, 42, 255);
        line(s, 2 * W/3, 8, 2 * W/3, H - 4, 65, 55, 42, 255);
        fill_rect(s, W/2 - 2, H/2 - 2, 4, 8, 35, 30, 24, 255); /* embrasure */
        fill_rect(s, W/2 - 1, H/2, 2, 4, 20, 18, 14, 255);
        break;
    case BT_REPAIR:
        /* garage + vehicle lift + tool rack + crane (KKND depot read) */
        fill_rect(s, 4, 6, W - 8, H - 10, ok, og, ob, 255);
        fill_rect(s, 6, 8, W - 12, H - 14, base.r, base.g, base.b, 255);
        fill_rect(s, 8, 10, W - 16, 8, lite.r, lite.g, lite.b, 255); /* roof */
        fill_rect(s, 10, 12, 4, 4, 50, 48, 40, 255); /* roof vents */
        fill_rect(s, W/2 - 2, 12, 4, 4, 50, 48, 40, 255);
        fill_rect(s, W - 14, 12, 4, 4, 50, 48, 40, 255);
        /* open bay + lift pad */
        fill_rect(s, 10, H - 28, W - 28, 18, ok, og, ob, 255);
        fill_rect(s, 12, H - 26, W - 32, 14, 38, 36, 32, 255);
        fill_rect(s, W/2 - 10, H - 22, 20, 8, 70, 68, 58, 255); /* lift platform */
        fill_rect(s, W/2 - 8, H - 20, 16, 4, 110, 100, 70, 255);
        line(s, W/2 - 10, H - 22, W/2 - 10, H - 12, 90, 85, 70, 255);
        line(s, W/2 + 10, H - 22, W/2 + 10, H - 12, 90, 85, 70, 255);
        /* tool rack annex (left) */
        fill_rect(s, 4, H/2 - 2, 10, H/2 - 6, ok, og, ob, 255);
        fill_rect(s, 5, H/2, 8, H/2 - 10, dark.r, dark.g, dark.b, 255);
        fill_rect(s, 6, H/2 + 2, 2, 6, 200, 160, 60, 255); /* tools */
        fill_rect(s, 9, H/2 + 1, 2, 7, 180, 180, 190, 255);
        /* overhead crane mast + jib + hook */
        fill_rect(s, W - 16, 4, 8, H - 20, ok, og, ob, 255);
        fill_rect(s, W - 14, 5, 5, H - 22, 95, 88, 70, 255);
        fill_rect(s, 16, 6, W - 32, 4, ok, og, ob, 255);
        fill_rect(s, 17, 7, W - 34, 2, 120, 110, 85, 255);
        line(s, W/2, 10, W/2, 20, 70, 65, 50, 255);
        disc(s, W/2, 22, 3, 80, 75, 55, 255);
        /* green service cross (clearer) */
        ring(s, W/2 - 6, H/2 + 4, 9, 2, 90, 200, 90, 255);
        fill_rect(s, W/2 - 14, H/2 + 2, 16, 4, 120, 220, 120, 255);
        fill_rect(s, W/2 - 8, H/2 - 4, 4, 16, 120, 220, 120, 255);
        /* parts crates */
        fill_rect(s, W - 22, H - 14, 8, 6, 140, 100, 55, 255);
        fill_rect(s, W - 20, H - 12, 4, 3, 180, 140, 70, 255);
        break;
    case BT_RESEARCH:
        /* tall lab + dish mast + instrument bank (KKND lab read) */
        fill_rect(s, 5, 12, W - 10, H - 16, ok, og, ob, 255);
        fill_rect(s, 7, 14, W - 14, H - 20, base.r, base.g, base.b, 255);
        fill_rect(s, 9, 16, W - 18, 10, lite.r, lite.g, lite.b, 255); /* upper band */
        /* glowing lab windows */
        fill_rect(s, 10, H/2 - 2, 8, 6, 180, 230, 255, 255);
        fill_rect(s, 22, H/2 - 2, 8, 6, 160, 220, 250, 255);
        fill_rect(s, 34, H/2 - 2, 8, 6, 180, 230, 255, 255);
        fill_rect(s, 12, H/2, 4, 2, 240, 250, 255, 255);
        fill_rect(s, 24, H/2, 4, 2, 230, 245, 255, 255);
        /* dish on tall mast */
        fill_rect(s, W/2 + 4, 2, 5, 18, ok, og, ob, 255);
        fill_rect(s, W/2 + 5, 3, 3, 16, 110, 100, 75, 255);
        disc(s, W/2 + 6, 12, 13, ok, og, ob, 255);
        disc(s, W/2 + 6, 12, 11, 215, 185, 85, 255);
        ring(s, W/2 + 6, 12, 8, 2, 170, 140, 55, 255);
        disc(s, W/2 + 6, 12, 4, 255, 245, 170, 255);
        disc(s, W/2 + 6, 12, 2, 255, 255, 220, 255); /* feed */
        line(s, W/2 + 6, 2, W/2 + 6, 12, 200, 190, 120, 255);
        /* side antenna stubs */
        fill_rect(s, 10, 6, 3, 10, 200, 200, 140, 255);
        fill_rect(s, 18, 4, 2, 12, 220, 220, 150, 255);
        disc(s, 11, 5, 2, 255, 240, 120, 255);
        disc(s, 19, 3, 2, 255, 230, 100, 255);
        /* instrument bank / console strip */
        fill_rect(s, 10, H - 18, W - 28, 8, dark.r, dark.g, dark.b, 255);
        fill_rect(s, 12, H - 16, 4, 4, 80, 220, 120, 255);
        fill_rect(s, 18, H - 16, 4, 4, 80, 160, 255, 255);
        fill_rect(s, 24, H - 16, 4, 4, 255, 180, 80, 255);
        fill_rect(s, 30, H - 16, 4, 4, 200, 100, 255, 255);
        break;
    default:
        (void)dark;
        break;
    }
    SDL_Texture *tex = SDL_CreateTextureFromSurface(r, s);
    SDL_FreeSurface(s);
    return tex;
}

/* ---------------- terrain tiles ---------------- */
SDL_Texture *sprites_make_terrain(SDL_Renderer *r, TerrainType t) {
    SDL_Surface *s = new_surf(TILE, TILE);
    Uint8 tr=0,tg=0,tb=0;
    /* Classic KKND2 wasteland: yellow-tan sand (R>>B, G slightly under R). */
    switch (t) {
        case T_WASTELAND: tr=228; tg=188; tb=98; break;
        case T_RUBBLE:    tr=168; tg=138; tb=88; break;
        case T_ROAD:      tr=175; tg=148; tb=98; break;
        case T_GRASS:     tr=242; tg=198; tb=92; break; /* sunlit desert */
        case T_WATER:     tr=72;  tg=128; tb=178; break;
        case T_ROCK:      tr=155; tg=142; tb=128; break;
        case T_SCRAP:     tr=240; tg=190; tb=78; break;
        default:          tr=228; tg=188; tb=98; break;
    }
    fill_rect(s, 0, 0, TILE, TILE, tr, tg, tb, 255);
    /* speckle for texture */
    for (int i = 0; i < 40; i++) {
        int x = (i*73) % TILE, y = (i*131) % TILE;
        int v = ((i*53) % 24) - 12;
        px(s, x, y,
           (Uint8)kknd_clampi(tr+v,0,255),
           (Uint8)kknd_clampi(tg+v,0,255),
           (Uint8)kknd_clampi(tb+v,0,255), 255);
    }
    if (t == T_SCRAP) {
        /* stacked scrap mounds (live parity with snapshot) */
        int cc = TILE / 2, cr = TILE / 2 + 2;
        for (int k = 0; k < 7; k++) {
            int ox = ((k * 7) % 14) - 7;
            int oy = ((k * 5) % 10) - 5 - (k / 3) * 2;
            int rad = 3 + (k & 1);
            disc(s, cc + ox, cr + oy, rad, 235, 190, 85, 255);
            disc(s, cc + ox - 1, cr + oy - rad / 2, rad - 1, 210, 165, 70, 255);
            disc(s, cc + ox + 1, cr + oy - rad + 1,
                 (rad > 2) ? rad - 2 : 1, 255, 215, 120, 255);
        }
    }
    if (t == T_WATER) {
        for (int i = 0; i < TILE; i += 4)
            line(s, 0, i, TILE, i, 60, 100, 150, 255);
    }
    if (t == T_ROCK) {
        for (int i = 0; i < 12; i++) {
            int x = (i*89) % TILE, y = (i*149) % TILE;
            disc(s, x, y, 3, 130, 124, 118, 255);
        }
    }
    SDL_Texture *tex = SDL_CreateTextureFromSurface(r, s);
    SDL_FreeSurface(s);
    return tex;
}

/* ---------------- bullets ---------------- */
static SDL_Texture *make_bullet(SDL_Renderer *r, int kind) {
    int S = 10;
    SDL_Surface *s = new_surf(S, S);
    switch (kind) {
    case 0: disc(s, 5, 5, 3, 255, 230, 120, 255); break;   /* MG tracer */
    case 1: disc(s, 5, 5, 4, 255, 160, 60, 255);  break;   /* shell */
    case 2: disc(s, 5, 5, 3, 120, 255, 160, 255); break;   /* laser */
    case 3: disc(s, 5, 5, 4, 255, 90, 90, 255);   break;   /* missile */
    default: disc(s, 5, 5, 3, 255, 255, 255, 255);
    }
    SDL_Texture *tex = SDL_CreateTextureFromSurface(r, s);
    SDL_FreeSurface(s);
    return tex;
}

int sprites_init(Sprites *sp, SDL_Renderer *r) {
    memset(sp, 0, sizeof(Sprites));
    for (int t = 0; t < T_COUNT; t++)
        sp->terrain[t] = sprites_make_terrain(r, (TerrainType)t);
    for (int t = 1; t < UT_COUNT; t++) {
        sp->unit[t][FACTION_SURVIVOR] = sprites_make_unit(r, (UnitType)t, FACTION_SURVIVOR);
        sp->unit[t][FACTION_EVOLVED]  = sprites_make_unit(r, (UnitType)t, FACTION_EVOLVED);
        sp->unit[t][FACTION_SERIES9]  = sprites_make_unit(r, (UnitType)t, FACTION_SERIES9);
    }
    for (int t = 1; t < BT_COUNT; t++) {
        sp->bld[t][FACTION_SURVIVOR] = sprites_make_bld(r, (BuildingType)t, FACTION_SURVIVOR);
        sp->bld[t][FACTION_EVOLVED]  = sprites_make_bld(r, (BuildingType)t, FACTION_EVOLVED);
        sp->bld[t][FACTION_SERIES9]  = sprites_make_bld(r, (BuildingType)t, FACTION_SERIES9);
    }
    for (int k = 0; k < 4; k++)
        sp->bullet[k] = make_bullet(r, k);

    sp->font_small = TTF_OpenFont("/usr/share/fonts/TTF/DejaVuSans.ttf", 14);
    if (!sp->font_small)
        sp->font_small = TTF_OpenFont("/usr/share/fonts/gnu-free/FreeSans.ttf", 14);
    sp->font_med = sp->font_small ? TTF_OpenFont("/usr/share/fonts/TTF/DejaVuSans.ttf", 20) : NULL;
    sp->font_big = sp->font_small ? TTF_OpenFont("/usr/share/fonts/TTF/DejaVuSans.ttf", 34) : NULL;
    if (!sp->font_small) {
        sp->font_small = TTF_OpenFont("/usr/share/fonts/TTF/DejaVuSans-Bold.ttf", 14);
    }
    return 1;
}

void sprites_free(Sprites *sp) {
    for (int t = 0; t < T_COUNT; t++)
        if (sp->terrain[t]) SDL_DestroyTexture(sp->terrain[t]);
    for (int t = 1; t < UT_COUNT; t++)
        for (int f = 0; f < MAX_FACTIONS; f++)
            if (sp->unit[t][f]) SDL_DestroyTexture(sp->unit[t][f]);
    for (int t = 1; t < BT_COUNT; t++)
        for (int f = 0; f < MAX_FACTIONS; f++)
            if (sp->bld[t][f]) SDL_DestroyTexture(sp->bld[t][f]);
    for (int k = 0; k < 4; k++)
        if (sp->bullet[k]) SDL_DestroyTexture(sp->bullet[k]);
    if (sp->font_small) TTF_CloseFont(sp->font_small);
    if (sp->font_med)   TTF_CloseFont(sp->font_med);
    if (sp->font_big)   TTF_CloseFont(sp->font_big);
}