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mirror of https://github.com/sehugg/8bitworkshop.git synced 2024-11-25 18:33:11 +00:00
8bitworkshop/presets/nes/shoot2.c
2019-07-14 12:18:34 -04:00

801 lines
27 KiB
C

/*
A shoot-em-up game.
Uses CHR RAM to draw attacker tiles at 8 different pixels,
then animates them in the nametable.
Sprites are used for the player, missiles, attackers, and stars.
*/
#include <stdlib.h>
#include <string.h>
#include <nes.h>
#include "neslib.h"
#define NES_MAPPER 2 // mapper 2 (UxROM mapper)
#define NES_CHR_BANKS 0 // CHR RAM
// APU (sound) support
#include "apu.h"
//#link "apu.c"
// BCD arithmetic support
#include "bcd.h"
//#link "bcd.c"
// VRAM update buffer
#include "vrambuf.h"
//#link "vrambuf.c"
#define COLS 32
#define ROWS 28
//#define DEBUG_FRAMERATE
/*{pal:"nes",layout:"nes"}*/
const char PALETTE[32] = {
0x0F,
0x11,0x24,0x3C, 0x00,
0x01,0x15,0x25, 0x00,
0x01,0x10,0x20, 0x00,
0x06,0x16,0x26, 0x00,
0x11,0x24,0x3C, 0x00,
0x01,0x15,0x25, 0x00,
0x31,0x35,0x3C, 0x00,
0x25,0x1C,0x3D
};
#define COLOR_PLAYER 3
#define COLOR_FORMATION 1
#define COLOR_ATTACKER 1
#define COLOR_MISSILE 3
#define COLOR_BOMB 2
#define COLOR_SCORE 2
#define COLOR_EXPLOSION 3
/*{w:8,h:8,bpp:1,count:128,brev:1,np:2,pofs:8,remap:[0,1,2,4,5,6,7,8,9,10,11,12]}*/
const char TILESET[128*8*2] = {
// font (0..63)
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x7C,0x7C,0x7C,0x38,0x00,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x6C,0x6C,0x48,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x6C,0xFE,0x6C,0xFE,0x6C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10,0xFE,0xD0,0xFE,0x16,0xFE,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xCE,0xDC,0x38,0x76,0xE6,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x6C,0x7C,0xEC,0xEE,0x7E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x38,0x30,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x70,0x70,0x70,0x70,0x70,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x70,0x38,0x38,0x38,0x38,0x38,0x30,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x6C,0x38,0x6C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x38,0xFE,0x38,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x60,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x60,0x60,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x0E,0x1E,0x3C,0x78,0xF0,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x7C,0xEE,0xEE,0xEE,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x78,0x38,0x38,0x38,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0x0E,0x7C,0xE0,0xEE,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFC,0x0E,0x3C,0x0E,0x0E,0xFC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3E,0x7E,0xEE,0xEE,0xFE,0x0E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFC,0xE0,0xFC,0x0E,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xE0,0xFC,0xEE,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0xEE,0x1C,0x1C,0x38,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0x7C,0xEE,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0xEE,0x7E,0x0E,0x3C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x60,0x60,0x00,0x00,0x60,0x60,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x60,0x60,0x00,0x00,0x60,0x60,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x1C,0x38,0x70,0x70,0x38,0x1C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0x00,0x00,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x70,0x38,0x1C,0x1C,0x38,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0x1C,0x38,0x00,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x7C,0xEE,0xEE,0xEE,0xE0,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0xEE,0xEE,0xFE,0xEE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFC,0xEE,0xFC,0xEE,0xEE,0xFC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0xE0,0xE0,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xF8,0xEC,0xEE,0xEE,0xEE,0xFC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0xE0,0xF0,0xE0,0xE0,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0xE0,0xF8,0xE0,0xE0,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xE0,0xEE,0xEE,0xEE,0x7E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0xEE,0xFE,0xEE,0xEE,0xEE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0x38,0x38,0x38,0x38,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x0E,0x0E,0x0E,0x0E,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0xFC,0xF8,0xEC,0xEE,0xEE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xE0,0xE0,0xE0,0xE0,0xEE,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xC6,0xEE,0xFE,0xFE,0xEE,0xEE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xCE,0xEE,0xFE,0xFE,0xEE,0xE6,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0xEE,0xEE,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0xFC,0xEE,0xEE,0xEE,0xFC,0xE0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xEE,0xEE,0xEE,0xEC,0x7E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFC,0xEE,0xEE,0xEE,0xFC,0xEE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xE0,0x7C,0x0E,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x38,0x38,0x38,0x38,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0xEE,0xEE,0xEE,0xEE,0x7C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0xEE,0xEE,0x6C,0x38,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0xEE,0xFE,0xFE,0xEE,0xC6,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0x7C,0x38,0x7C,0xEE,0xEE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEE,0xEE,0xEE,0x7C,0x38,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x1C,0x38,0x70,0xE0,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/*{w:16,h:16,bpp:1,count:16,brev:1,np:2,pofs:8,remap:[5,0,1,2,4,6,7,8,9,10,11,12]}*/
// formation enemy (64,66)
0x0F,0x13,0x03,0x03,0x01,0x01,0x00,0x00,0x0C,0x11,0x04,0x08,0x12,0x04,0x08,0x08,
0x0C,0x13,0x03,0x03,0x03,0x01,0x01,0x00,0x0C,0x10,0x01,0x0C,0x30,0x02,0x04,0x18,
0xF8,0xE4,0xE0,0xE0,0xC0,0xC0,0x80,0x00,0x18,0x44,0x10,0x08,0x24,0x10,0x08,0x08,
0x18,0x64,0xE0,0xE0,0xE0,0xC0,0xC0,0x80,0x18,0x04,0x40,0x18,0x06,0x20,0x10,0x0C,
// attackers (68)
0x00,0x00,0x04,0x08,0x04,0x03,0x03,0x0F,0x00,0x00,0x04,0x08,0x04,0x00,0x01,0x00,
0x03,0x01,0x01,0x00,0x00,0x00,0x00,0x00,0x30,0x02,0x04,0x18,0x00,0x00,0x00,0x00,
0x00,0x00,0x10,0x08,0x10,0x60,0xE0,0xE0,0x00,0x00,0x10,0x08,0x10,0x00,0x40,0x18,
0xE0,0xC0,0xC0,0x80,0x00,0x00,0x00,0x00,0x06,0x20,0x10,0x0C,0x00,0x00,0x00,0x00,
0x00,0x00,0x02,0x04,0x04,0x03,0x03,0x03,0x00,0x00,0x02,0x04,0x04,0x20,0x11,0x0C,
0x03,0x07,0x03,0x03,0x02,0x00,0x00,0x00,0x00,0x20,0x1C,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x08,0x08,0x10,0xE0,0xE0,0x00,0x00,0x00,0x08,0x08,0x10,0x00,0x40,
0xE0,0xC0,0xC0,0x00,0x00,0x00,0x00,0x00,0x10,0x0C,0x02,0x20,0x10,0x0C,0x00,0x00,
0x00,0x00,0x02,0x04,0x04,0x03,0x03,0x03,0x00,0x00,0x02,0x04,0x04,0x20,0x11,0x0C,
0x03,0x07,0x03,0x03,0x02,0x00,0x00,0x00,0x00,0x20,0x1C,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x08,0x08,0x10,0xE0,0xE0,0x00,0x00,0x00,0x08,0x08,0x10,0x00,0x40,
0xE0,0xC0,0xC0,0x00,0x00,0x00,0x00,0x00,0x10,0x0C,0x02,0x20,0x10,0x0C,0x00,0x00,
0x00,0x00,0x01,0x01,0x01,0x01,0x03,0x03,0x00,0x00,0x01,0x11,0x08,0x04,0x01,0x20,
0x07,0x07,0x03,0x02,0x00,0x00,0x00,0x00,0x10,0x08,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x80,0x00,0x04,0xCC,0xF0,0xE0,0x00,0x00,0x80,0x00,0x04,0x0C,0x00,0x40,
0xC0,0xC0,0x80,0x00,0x00,0x00,0x00,0x00,0x20,0x10,0x08,0x80,0x40,0x20,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x04,0x02,0x11,0x08,0x04,
0x03,0x03,0x07,0x01,0x00,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x30,0x20,0x60,0xF0,0xFC,0x00,0x00,0x00,0x30,0x20,0x00,0x40,0x04,
0xFC,0xE0,0xC0,0x80,0x00,0x00,0x00,0x00,0x2C,0x00,0x20,0x18,0x80,0x40,0x60,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x03,0x07,0x00,0x00,0x00,0x10,0x10,0x08,0x04,0x00,
0x07,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x02,0x02,0x02,0x00,0x00,
0x00,0x00,0x00,0x08,0x34,0xE0,0xE0,0xF0,0x00,0x80,0x80,0x88,0x94,0x00,0x40,0x00,
0xFA,0xE4,0x00,0x00,0x00,0x00,0x00,0x00,0x2A,0x04,0x80,0x40,0x20,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x07,0x00,0x00,0x01,0x09,0x08,0x04,0x02,0x00,
0x0F,0x07,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x04,0x08,0x09,0x01,0x00,
0x00,0x00,0x00,0x00,0x08,0x14,0xE0,0xE0,0x00,0x00,0x00,0x00,0x88,0x94,0x00,0x40,
0xC0,0xE0,0xE0,0x14,0x08,0x00,0x00,0x00,0x00,0x40,0x00,0x94,0x88,0x00,0x00,0x00,
0x01,0x01,0x01,0x00,0x00,0x01,0x11,0x11,0x01,0x01,0x02,0x07,0x01,0x21,0x21,0x2B,
0x11,0x16,0x1E,0x15,0x10,0x10,0x10,0x10,0x3F,0x3F,0x3F,0x3D,0x3B,0x3C,0x28,0x28,
0x40,0x40,0xC0,0x00,0x00,0x40,0x44,0x44,0xC0,0xC0,0x20,0xF0,0xC0,0xC2,0xC2,0xEA,
0x44,0x34,0x3C,0x54,0x04,0x04,0x04,0x04,0xFE,0xFE,0xFE,0xDE,0xEE,0x1E,0x0A,0x0A,
// player ship (96)
0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
// bullet (100)
0x00,0x00,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
// stars (102)
0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
// explosions (112)
0x00,0x00,0x00,0x08,0x04,0x03,0x06,0x05,0x00,0x00,0x00,0x0C,0x06,0x04,0x00,0x18,
0x05,0x06,0x07,0x00,0x00,0x00,0x00,0x00,0x18,0x00,0x08,0x09,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x08,0x90,0xE0,0x90,0xD0,0x00,0x00,0x00,0x18,0x30,0x10,0x00,0x0C,
0xF0,0x20,0xE0,0x80,0x00,0x00,0x00,0x00,0x0C,0x10,0x18,0xC8,0x00,0x00,0x00,0x00,
0x00,0x04,0x12,0x0C,0x42,0x30,0x00,0x19,0x00,0x00,0x00,0x0A,0x00,0x06,0x08,0x00,
0x11,0x04,0x0C,0x00,0x21,0x46,0x00,0x00,0x04,0x10,0x02,0x0C,0x00,0x00,0x00,0x00,
0x00,0x40,0x08,0x91,0xA2,0x04,0x80,0xCC,0x00,0x00,0x00,0x20,0x00,0x30,0x08,0x00,
0xC4,0x10,0x1A,0x80,0x20,0x10,0x00,0x00,0x10,0x04,0xA0,0x98,0x80,0x00,0x00,0x00,
0x61,0x20,0x00,0x04,0x00,0xC4,0x08,0x10,0x00,0x00,0x04,0x06,0x09,0x02,0x10,0x14,
0x10,0x00,0x42,0xC8,0x80,0x00,0x10,0x30,0x34,0x10,0x11,0x02,0x00,0x00,0x00,0x00,
0x86,0xC4,0x00,0x10,0x01,0x10,0x08,0x04,0x00,0x00,0x10,0x30,0x48,0x20,0x04,0x14,
0x04,0x00,0x20,0x89,0x00,0x84,0xC6,0x43,0x16,0x04,0x44,0xA0,0x00,0x00,0x00,0x00,
0x00,0x00,0x02,0x08,0x00,0x06,0x02,0x00,0x00,0x40,0x08,0x01,0x11,0x15,0x00,0x38,
0x30,0x02,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x00,0x10,0x00,0x04,0x40,0x00,0x00,
0x00,0x00,0x20,0x08,0x00,0x30,0x20,0x00,0x02,0x00,0x08,0x40,0x44,0x54,0x00,0x0E,
0x06,0x20,0x80,0x80,0x00,0x00,0x00,0x00,0x0C,0x80,0x04,0x80,0x00,0x11,0x00,0x00,
};
#define CHAR(x) ((x)-' ')
#define BLANK 0
void clrscr() {
vrambuf_clear();
ppu_off();
vram_adr(NAMETABLE_A);
vram_fill(BLANK, 32*28);
vram_adr(0x0);
ppu_on_all();
}
/////
char in_rect(byte x, byte y, byte x0, byte y0, byte w, byte h) {
return ((byte)(x-x0) < w && (byte)(y-y0) < h); // unsigned
}
void draw_bcd_word(byte col, byte row, word bcd) {
byte j;
static char buf[5];
buf[4] = CHAR('0');
for (j=3; j<0x80; j--) {
buf[j] = CHAR('0'+(bcd&0xf));
bcd >>= 4;
}
vrambuf_put(NTADR_A(col, row), buf, 5);
}
// GAME CODE
#define NSPRITES 8 // max number of sprites
#define NMISSILES 8 // max number of missiles
#define YOFFSCREEN 240 // offscreen y position (hidden)
// sprite indexes
#define PLYRMISSILE 7 // player missile
#define PLYRSPRITE 7 // player sprite
#define BOOMSPRITE 6 // explosion sprite
// nametable entries
#define NAME_SHIP 96
#define NAME_MISSILE 100
#define NAME_BOMB 104
#define NAME_EXPLODE 112
#define NAME_ENEMY 68
#define SSRC_FORM1 64 // name for formation source sprites
#define SDST_FORM1 128 // start of shifted formation table
typedef struct {
byte shape;
} FormationEnemy;
// should be power of 2 length
typedef struct {
byte findex;
byte shape;
word x;
word y;
byte dir;
byte returning;
} AttackingEnemy;
typedef struct {
byte xpos;
byte ypos;
signed char dx;
signed char dy;
} Missile;
typedef struct {
byte x;
byte y;
byte name;
byte tag;
} Sprite;
#define ENEMIES_PER_ROW 8
#define ENEMY_ROWS 4
#define MAX_IN_FORMATION (ENEMIES_PER_ROW*ENEMY_ROWS)
#define MAX_ATTACKERS 6
FormationEnemy formation[MAX_IN_FORMATION];
AttackingEnemy attackers[MAX_ATTACKERS];
Missile missiles[NMISSILES];
Sprite vsprites[NSPRITES];
byte formation_offset_x;
signed char formation_direction;
byte current_row;
byte player_x;
const byte player_y = 190;
byte player_exploding;
byte enemy_exploding;
byte enemies_left;
word player_score;
void copy_sprites() {
byte i;
byte oamid = 128; // so we don't clear stars...
for (i=0; i<NSPRITES; i++) {
Sprite* spr = &vsprites[i];
if (spr->y != YOFFSCREEN) {
byte y = spr->y;
byte x = spr->x;
byte chr = spr->name;
byte attr = spr->tag;
if (attr & 0x40) chr += 2; // horiz flip, swap tiles
oamid = oam_spr(x, y, chr, attr, oamid);
oamid = oam_spr(x+8, y, chr^2, attr, oamid);
}
}
// copy all "shadow missiles" to video memory
for (i=0; i<NMISSILES; i++) {
Missile* mis = &missiles[i];
if (mis->ypos != YOFFSCREEN) {
oamid = oam_spr(mis->xpos, mis->ypos, NAME_MISSILE,
(i==7)?COLOR_MISSILE:COLOR_BOMB,
oamid);
}
}
oam_hide_rest(oamid);
}
void add_score(word bcd) {
player_score = bcd_add(player_score, bcd);
draw_bcd_word(1, 1, player_score);
}
void clrobjs() {
byte i;
memset(vsprites, 0, sizeof(vsprites));
for (i=0; i<NSPRITES; i++) {
vsprites[i].y = YOFFSCREEN;
}
for (i=0; i<NMISSILES; i++) {
missiles[i].ypos = YOFFSCREEN;
}
}
void setup_formation() {
byte i;
memset(formation, 0, sizeof(formation));
memset(attackers, 0, sizeof(attackers));
for (i=0; i<MAX_IN_FORMATION; i++) {
byte flagship = i < ENEMIES_PER_ROW;
formation[i].shape = flagship ? SDST_FORM1 : SDST_FORM1;
}
enemies_left = MAX_IN_FORMATION;
formation_offset_x = 8;
}
void draw_row(byte row) {
static char buf[32];
register byte i;
register byte x = formation_offset_x / 8;
byte xd = (formation_offset_x & 7) * 3;
byte y = 3 + row * 2;
memset(buf, BLANK, sizeof(buf));
for (i=0; i<ENEMIES_PER_ROW; i++) {
byte shape = formation[i + row*ENEMIES_PER_ROW].shape;
if (shape) {
shape += xd;
buf[x] = shape;
buf[x+1] = shape+1;
buf[x+2] = shape+2;
}
x += 3;
}
vrambuf_put(NTADR_A(0, y), buf, sizeof(buf));
}
void draw_next_row() {
draw_row(current_row);
if (++current_row == ENEMY_ROWS) {
current_row = 0;
formation_offset_x += formation_direction;
if (formation_offset_x == 63) {
formation_direction = -1;
}
else if (formation_offset_x == 8) {
formation_direction = 1;
}
}
}
#define FLIPX 0x40
#define FLIPY 0x80
#define FLIPXY 0xc0
const byte DIR_TO_CODE[32] = {
0|FLIPXY, 1|FLIPXY, 2|FLIPXY, 3|FLIPXY, 4|FLIPXY, 5|FLIPXY, 6|FLIPXY, 6|FLIPXY,
6|FLIPX, 6|FLIPX, 5|FLIPX, 4|FLIPX, 3|FLIPX, 2|FLIPX, 1|FLIPX, 0|FLIPX,
0, 1, 2, 3, 4, 5, 6, 6,
6|FLIPY, 6|FLIPY, 5|FLIPY, 4|FLIPY, 3|FLIPY, 2|FLIPY, 1|FLIPY, 0|FLIPY,
};
// sine table, pre-multiplied by 2
const int SINTBL2[32] = {
0, 25*2, 49*2, 71*2, 90*2, 106*2, 117*2, 125*2,
127*2, 125*2, 117*2, 106*2, 90*2, 71*2, 49*2, 25*2,
0*2, -25*2, -49*2, -71*2, -90*2, -106*2, -117*2, -125*2,
-127*2, -125*2, -117*2, -106*2, -90*2, -71*2, -49*2, -25*2,
};
#define ISIN(x) (SINTBL2[(x) & 31])
#define ICOS(x) ISIN(x+8)
#define FORMATION_X0 0
#define FORMATION_Y0 19
#define FORMATION_XSPACE 24
#define FORMATION_YSPACE 16
byte get_attacker_x(byte formation_index) {
byte column = (formation_index % ENEMIES_PER_ROW);
return FORMATION_XSPACE*column + FORMATION_X0 + formation_offset_x;
}
byte get_attacker_y(byte formation_index) {
byte row = formation_index / ENEMIES_PER_ROW;
return FORMATION_YSPACE*row + FORMATION_Y0;
}
void draw_attacker(byte i) {
AttackingEnemy* a = &attackers[i];
if (a->findex) {
byte code = DIR_TO_CODE[a->dir & 31];
vsprites[i].name = NAME_ENEMY + (code & 7)*4; // tile
vsprites[i].tag = code & FLIPXY; // flip h/v
vsprites[i].x = a->x >> 8;
vsprites[i].y = a->y >> 8;
} else {
vsprites[i].y = YOFFSCREEN;
}
}
void draw_attackers() {
byte i;
for (i=0; i<MAX_ATTACKERS; i++) {
draw_attacker(i);
}
}
void return_attacker(register AttackingEnemy* a) {
byte fi = a->findex-1;
byte destx = get_attacker_x(fi);
byte desty = get_attacker_y(fi);
byte ydist = desty - (a->y >> 8);
// are we close to our formation slot?
if (ydist == 0) {
// convert back to formation enemy
formation[fi].shape = a->shape;
a->findex = 0;
} else {
a->dir = (ydist + 16) & 31;
a->x = destx << 8;
a->y += 128;
}
}
void fly_attacker(register AttackingEnemy* a) {
a->x += ISIN(a->dir);
a->y += ICOS(a->dir);
if ((a->y >> 8) == 0) {
a->returning = 1;
}
}
void move_attackers() {
byte i;
for (i=0; i<MAX_ATTACKERS; i++) {
AttackingEnemy* a = &attackers[i];
if (a->findex) {
if (a->returning)
return_attacker(a);
else
fly_attacker(a);
}
}
}
void think_attackers() {
byte i;
for (i=0; i<MAX_ATTACKERS; i++) {
AttackingEnemy* a = &attackers[i];
if (a->findex) {
// rotate?
byte x = a->x >> 8;
byte y = a->y >> 8;
// don't shoot missiles after player exploded
if (y < 112 || player_exploding) {
if (x < 128) {
a->dir++;
} else {
a->dir--;
}
} else {
// lower half of screen
// shoot a missile?
if (missiles[i].ypos == YOFFSCREEN) {
missiles[i].ypos = y+16;
missiles[i].xpos = x;
missiles[i].dy = 2;
}
}
}
}
}
void formation_to_attacker(byte formation_index) {
byte i;
// out of bounds? return
if (formation_index >= MAX_IN_FORMATION)
return;
// nobody in formation? return
if (!formation[formation_index].shape)
return;
// find an empty attacker slot
for (i=0; i<MAX_ATTACKERS; i++) {
AttackingEnemy* a = &attackers[i];
if (a->findex == 0) {
a->x = get_attacker_x(formation_index) << 8;
a->y = get_attacker_y(formation_index) << 8;
a->shape = formation[formation_index].shape;
a->findex = formation_index+1;
a->dir = 0;
a->returning = 0;
formation[formation_index].shape = 0;
break;
}
}
}
void draw_player() {
vsprites[PLYRSPRITE].x = player_x;
vsprites[PLYRSPRITE].y = player_y;
vsprites[PLYRSPRITE].name = NAME_SHIP;
vsprites[PLYRSPRITE].tag = COLOR_PLAYER;
}
void move_player() {
byte joy = pad_poll(0);
// move left/right?
if ((joy & PAD_LEFT) && player_x > 16) player_x--;
if ((joy & PAD_RIGHT) && player_x < 224) player_x++;
// shoot missile?
if ((joy & PAD_A) && missiles[PLYRMISSILE].ypos == YOFFSCREEN) {
missiles[PLYRMISSILE].ypos = player_y-8; // must be multiple of missile speed
missiles[PLYRMISSILE].xpos = player_x+4; // player X position
missiles[PLYRMISSILE].dy = -4; // player missile speed
}
vsprites[PLYRMISSILE].x = player_x;
}
void move_missiles() {
byte i;
for (i=0; i<8; i++) {
if (missiles[i].ypos != YOFFSCREEN) {
// hit the bottom or top?
if ((byte)(missiles[i].ypos += missiles[i].dy) > YOFFSCREEN) {
missiles[i].ypos = YOFFSCREEN;
}
}
}
}
void blowup_at(byte x, byte y) {
vsprites[BOOMSPRITE].tag = COLOR_EXPLOSION;
vsprites[BOOMSPRITE].name = NAME_EXPLODE; // TODO
vsprites[BOOMSPRITE].x = x;
vsprites[BOOMSPRITE].y = y;
enemy_exploding = 1;
}
void animate_enemy_explosion() {
if (enemy_exploding) {
// animate next frame
if (enemy_exploding >= 8) {
enemy_exploding = 0; // hide explosion after 4 frames
vsprites[BOOMSPRITE].y = YOFFSCREEN;
} else {
vsprites[BOOMSPRITE].name = NAME_EXPLODE + (enemy_exploding += 4); // TODO
}
}
}
void animate_player_explosion() {
byte z = player_exploding;
if (z <= 3) {
if (z == 3) {
vsprites[PLYRSPRITE].y = YOFFSCREEN;
} else {
vsprites[PLYRSPRITE].name = NAME_EXPLODE + z*4;
}
}
}
void hide_player_missile() {
missiles[PLYRMISSILE].ypos = YOFFSCREEN;
}
void does_player_shoot_formation() {
byte mx = missiles[PLYRMISSILE].xpos + 4;
byte my = missiles[PLYRMISSILE].ypos;
signed char row = (my - FORMATION_Y0) / FORMATION_YSPACE;
if (missiles[PLYRMISSILE].ypos == YOFFSCREEN)
return;
if (row >= 0 && row < ENEMY_ROWS) {
// ok if unsigned (in fact, must be due to range)
byte xoffset = mx - FORMATION_X0 - formation_offset_x;
byte column = xoffset / FORMATION_XSPACE;
byte localx = xoffset - column * FORMATION_XSPACE;
if (column < ENEMIES_PER_ROW && localx < 16) {
char index = column + row * ENEMIES_PER_ROW;
if (formation[index].shape) {
formation[index].shape = 0;
enemies_left--;
blowup_at(get_attacker_x(index), get_attacker_y(index));
hide_player_missile();
add_score(2);
}
}
}
}
void does_player_shoot_attacker() {
byte mx = missiles[PLYRMISSILE].xpos + 4;
byte my = missiles[PLYRMISSILE].ypos;
byte i;
if (missiles[PLYRMISSILE].ypos == YOFFSCREEN)
return;
for (i=0; i<MAX_ATTACKERS; i++) {
AttackingEnemy* a = &attackers[i];
if (a->findex && in_rect(mx, my, a->x >> 8, a->y >> 8, 16, 16)) {
blowup_at(a->x >> 8, a->y >> 8);
a->findex = 0;
enemies_left--;
hide_player_missile();
add_score(5);
break;
}
}
}
void does_missile_hit_player() {
byte i;
if (player_exploding)
return;
for (i=0; i<MAX_ATTACKERS; i++) {
if (missiles[i].ypos != YOFFSCREEN &&
in_rect(missiles[i].xpos, missiles[i].ypos + 16,
player_x, player_y, 16, 16)) {
player_exploding = 1;
break;
}
}
}
void new_attack_wave() {
byte i = rand();
byte j;
// find a random slot that has an enemy
for (j=0; j<MAX_IN_FORMATION; j++) {
i = (i+1) & (MAX_IN_FORMATION-1);
// anyone there?
if (formation[i].shape) {
formation_to_attacker(i);
formation_to_attacker(i+1);
formation_to_attacker(i+ENEMIES_PER_ROW);
formation_to_attacker(i+ENEMIES_PER_ROW+1);
break;
}
}
}
void new_player_ship() {
player_exploding = 0;
player_x = 120;
draw_player();
}
void set_sounds() {
byte i;
// these channels decay, so ok to always enable
byte enable = ENABLE_PULSE0|ENABLE_PULSE1|ENABLE_NOISE;
// missile fire sound
if (missiles[PLYRMISSILE].ypos != YOFFSCREEN) {
APU_PULSE_SUSTAIN(0, 255-missiles[PLYRMISSILE].ypos, DUTY_50, 6);
} else {
APU_PULSE_SET_VOLUME(0, DUTY_50, 0);
}
// enemy explosion sound
if (player_exploding && player_exploding < 8) {
APU_NOISE_DECAY(8 + player_exploding, 5, 15);
} else if (enemy_exploding) {
APU_NOISE_DECAY(8 + enemy_exploding, 2, 8);
}
// set diving sounds for spaceships
for (i=0; i<2; i++) {
register AttackingEnemy* a = i ? &attackers[4] : &attackers[0];
if (a->findex && !a->returning) {
byte y = a->y >> 8;
APU_TRIANGLE_SUSTAIN(0x100 | y);
enable |= ENABLE_TRIANGLE;
break;
}
}
APU_ENABLE(enable);
}
void init_stars() {
byte oamid = 0; // 32 slots = 128 bytes
byte i;
for (i=0; i<32; i++) {
oamid = oam_spr(rand(), i*8, 103+(i&3), 0|OAM_BEHIND, oamid);
}
}
/*
void draw_stars_c() {
byte i;
for (i=0; i<32; i++) {
++OAMBUF[i].y;
}
}
*/
void draw_stars() {
asm("ldy #0"); // start with Y = 0
asm("clc"); // clear carry for addition
asm("@1: lda $200,y");// read from OAM buffer
asm("adc #1"); // increment
asm("sta $200,y"); // write to OAM buffer
asm("iny"); // increment Y by 4
asm("iny");
asm("iny");
asm("iny");
asm("bpl @1"); // branch while < 128
}
void play_round() {
register byte framecount;
register byte t0;
byte end_timer = 255;
add_score(0);
//putbytes(NTADR_A(0, 1), "PLAYER 1", 8);
setup_formation();
clrobjs();
formation_direction = 1;
framecount = 0;
new_player_ship();
while (end_timer) {
if (player_exploding) {
if ((framecount & 7) == 1) {
animate_player_explosion();
if (++player_exploding > 32 && enemies_left) {
new_player_ship();
}
}
} else {
if (framecount == 0 || enemies_left < 8) {
new_attack_wave();
}
move_player();
}
move_attackers();
move_missiles();
if (framecount & 1)
does_player_shoot_formation();
else
does_player_shoot_attacker();
draw_attackers();
if ((framecount & 0xf) == 0) {
think_attackers();
} else {
switch (framecount & 3) {
case 1: animate_enemy_explosion(); // continue...
case 2: does_missile_hit_player(); break;
case 3: draw_stars(); break;
}
set_sounds();
if (!enemies_left) end_timer--;
draw_next_row();
}
vrambuf_flush();
copy_sprites();
#ifdef DEBUG_FRAMERATE
putchar(t0 & 31, 27, CHAR(' '));
putchar(framecount & 31, 27, CHAR(' '));
#endif
framecount++;
t0 = nesclock();
#ifdef DEBUG_FRAMERATE
putchar(t0 & 31, 27, CHAR('C'));
putchar(framecount & 31, 27, CHAR('F'));
#endif
}
}
// turn off aggressive inlining to save a few bytes
// functions after this point aren't called often
#pragma codesize(100)
void set_shifted_pattern(const byte* src, word dest, byte shift) {
static byte buf[16*3];
byte y;
for (y=0; y<16; y++) {
byte a = src[y];
byte b = src[y+32];
buf[y] = a>>shift;
buf[y+16] = b>>shift | a<<(8-shift);
buf[y+32] = b<<(8-shift);
}
vram_adr(dest);
vram_write(buf, sizeof(buf));
}
void setup_graphics() {
byte i;
word src;
word dest;
// copy background
vram_adr(0x0);
vram_write(TILESET, sizeof(TILESET));
// copy sprites
vram_adr(0x1000);
vram_write(TILESET, sizeof(TILESET));
// write shifted versions of formation ships
src = SSRC_FORM1*16;
dest = SDST_FORM1*16;
for (i=0; i<8; i++) {
if (i==4) src += 16;
set_shifted_pattern(&TILESET[src], dest, i);
dest += 3*16;
}
// activate vram buffer
vrambuf_clear();
set_vram_update(updbuf);
}
void main() {
setup_graphics();
apu_init();
player_score = 0;
while (1) {
pal_all(PALETTE);
oam_clear();
oam_size(1); // 8x16 sprites
clrscr();
init_stars();
play_round();
}
}