// Sprite demo: bounces a 16x16 ball sprite around the screen using
// surfaceBlitMasked. The ball is embedded as a `const JoeyAssetT`
// directly in this file, so no .jas file or runtime allocation is
// involved -- this exercises the static / embedded path. Press ESC
// to quit.
//
// Each frame we redraw only the ball's old and new bounding boxes
// (and present those two small rects), so the cost stays small even
// with the slow 68000-class c2p in the ST and Amiga ports.

#include <stdio.h>

#include <joey/joey.h>

#define BALL_W           16
#define BALL_H           16

#define BALL_PALETTE_IDX 0

#define COLOR_BG         0
#define COLOR_TRANSPARENT 0   // first palette slot doubles as mask

// 16x16 ball sprite, 4bpp packed (8 bytes per row):
//   0 = transparent (mask)
//   2 = ball body (yellow)
//   3 = highlight (white)
// High nibble of each byte is the LEFT pixel.
static const uint8_t gBallPixels[BALL_H * 8] = {
    0x00, 0x00, 0x22, 0x22, 0x22, 0x22, 0x00, 0x00,  // row  0
    0x00, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x00,  // row  1
    0x02, 0x22, 0x32, 0x22, 0x22, 0x22, 0x22, 0x20,  // row  2
    0x02, 0x23, 0x32, 0x22, 0x22, 0x22, 0x22, 0x20,  // row  3
    0x22, 0x33, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row  4
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row  5
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row  6
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row  7
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row  8
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row  9
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  // row 10
    0x02, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x20,  // row 11
    0x02, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x20,  // row 12
    0x00, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x00,  // row 13
    0x00, 0x00, 0x22, 0x22, 0x22, 0x22, 0x00, 0x00,  // row 14
    0x00, 0x00, 0x00, 0x22, 0x22, 0x00, 0x00, 0x00   // row 15
};

// Build the embedded ball asset at runtime. We could declare a
// `static const JoeyAssetT` with this same data, but ORCA/C 2.1
// does not handle a file-scope static struct whose pointer field is
// initialized from another static array's address (linker complains
// of unresolved references). Building the struct in main() with a
// local sidesteps the quirk and costs only a handful of stores.
static void buildBallAsset(JoeyAssetT *ball) {
    uint16_t i;

    ball->width      = BALL_W;
    ball->height     = BALL_H;
    ball->hasPalette = true;
    ball->pixels     = gBallPixels;
    for (i = 0; i < 16; i++) {
        ball->palette[i] = 0x0000;
    }
    ball->palette[2] = 0x0FF0;  // yellow body
    ball->palette[3] = 0x0FFF;  // white highlight
}


static void initialPaint(SurfaceT *screen) {
    surfaceClear(screen, COLOR_BG);
    surfacePresent(screen);
}


int main(void) {
    JoeyConfigT  config;
    SurfaceT    *screen;
    JoeyAssetT   ball;
    int16_t      x;
    int16_t      y;
    int16_t      vx;
    int16_t      vy;
    int16_t      lastX;
    int16_t      lastY;

    config.hostMode     = HOST_MODE_TAKEOVER;
    config.codegenBytes = 32 * 1024;
    config.maxSurfaces  = 4;
    config.audioBytes   = 64 * 1024;
    config.assetBytes   = 128 * 1024;

    if (!joeyInit(&config)) {
        fprintf(stderr, "joeyInit failed: %s\n", joeyLastError());
        return 1;
    }

    screen = surfaceGetScreen();
    if (screen == NULL) {
        fprintf(stderr, "surfaceGetScreen returned NULL\n");
        joeyShutdown();
        return 1;
    }

    buildBallAsset(&ball);
    joeyAssetApplyPalette(screen, BALL_PALETTE_IDX, &ball);
    scbSetRange(screen, 0, SURFACE_HEIGHT - 1, BALL_PALETTE_IDX);
    initialPaint(screen);

    x     = 40;
    y     = 30;
    vx    = 2;
    vy    = 1;
    lastX = x;
    lastY = y;

    surfaceBlitMasked(screen, &ball, x, y, COLOR_TRANSPARENT);
    surfacePresentRect(screen, x, y, BALL_W, BALL_H);

    for (;;) {
        joeyWaitVBL();
        joeyInputPoll();
        if (joeyKeyPressed(KEY_ESCAPE)) {
            break;
        }

        // Erase old ball position by clearing its bounding rect. Any
        // pixel outside the ball that we wrote (we wrote no pixels
        // outside, since blitMasked respects transparency) stays as
        // background already.
        fillRect(screen, lastX, lastY, BALL_W, BALL_H, COLOR_BG);
        surfacePresentRect(screen, lastX, lastY, BALL_W, BALL_H);

        x = (int16_t)(x + vx);
        y = (int16_t)(y + vy);
        if (x <= 0)                         { x = 0;                         vx = (int16_t)-vx; }
        if (x >= SURFACE_WIDTH  - BALL_W)   { x = SURFACE_WIDTH  - BALL_W;   vx = (int16_t)-vx; }
        if (y <= 0)                         { y = 0;                         vy = (int16_t)-vy; }
        if (y >= SURFACE_HEIGHT - BALL_H)   { y = SURFACE_HEIGHT - BALL_H;   vy = (int16_t)-vy; }

        surfaceBlitMasked(screen, &ball, x, y, COLOR_TRANSPARENT);
        surfacePresentRect(screen, x, y, BALL_W, BALL_H);

        lastX = x;
        lastY = y;
    }

    joeyShutdown();
    return 0;
}