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8bitworkshop/src/platform/galaxian.js

407 lines
14 KiB
JavaScript

"use strict";
var GALAXIAN_PRESETS = [
{id:'gfxtest.c', name:'Graphics Test'},
{id:'shoot2.c', name:'Solarian Game'},
];
var GALAXIAN_KEYCODE_MAP = makeKeycodeMap([
[Keys.VK_SPACE, 0, 0x10], // P1
[Keys.VK_LEFT, 0, 0x4],
[Keys.VK_RIGHT, 0, 0x8],
[Keys.VK_S, 1, 0x10], // P2
[Keys.VK_A, 1, 0x4],
[Keys.VK_D, 1, 0x8],
[Keys.VK_5, 0, 0x1],
[Keys.VK_1, 1, 0x1],
[Keys.VK_2, 1, 0x2],
]);
var SCRAMBLE_KEYCODE_MAP = makeKeycodeMap([
[Keys.VK_UP, 0, -0x1], // P1
[Keys.VK_SHIFT, 0, -0x2], // fire
[Keys.VK_7, 0, -0x4], // credit
[Keys.VK_SPACE, 0, -0x8], // bomb
[Keys.VK_RIGHT, 0, -0x10],
[Keys.VK_LEFT, 0, -0x20],
[Keys.VK_6, 0, -0x40],
[Keys.VK_5, 0, -0x80],
[Keys.VK_1, 1, -0x80],
[Keys.VK_2, 1, -0x40],
[Keys.VK_DOWN, 2, -0x40],
//[Keys.VK_UP, 2, -0x10],
]);
var GalaxianPlatform = function(mainElement, options) {
var self = this;
this.__proto__ = new BaseZ80Platform();
options = options || {};
var romSize = options.romSize || 0x4000;
var gfxBase = options.gfxBase || 0x2800;
var palBase = options.palBase || 0x3800;
var keyMap = options.keyMap || GALAXIAN_KEYCODE_MAP;
var missileWidth = options.missileWidth || 4;
var missileOffset = options.missileOffset || 0;
var cpu, ram, vram, oram, membus, iobus, rom, palette, outlatches;
var video, audio, timer, pixels;
var psg1, psg2;
var inputs;
var interruptEnabled = 0;
var starsEnabled = 0;
var watchdog_counter;
var frameCounter = 0;
var XTAL = 18432000.0;
var scanlinesPerFrame = 264;
var cpuFrequency = XTAL/6; // 3.072 MHz
var hsyncFrequency = XTAL/3/192/2; // 16 kHz
var vsyncFrequency = hsyncFrequency/132/2; // 60.606060 Hz
var vblankDuration = 1/vsyncFrequency * (20/132); // 2500 us
var cpuCyclesPerLine = cpuFrequency/hsyncFrequency;
var INITIAL_WATCHDOG = 8;
var showOffscreenObjects = false;
var stars = [];
for (var i=0; i<256; i++)
stars[i] = noise();
function drawScanline(pixels, sl) {
if (sl < 16 && !showOffscreenObjects) return; // offscreen
if (sl >= 240 && !showOffscreenObjects) return; // offscreen
// draw tiles
var pixofs = sl*264;
var outi = pixofs; // starting output pixel in frame buffer
for (var xx=0; xx<32; xx++) {
var xofs = xx;
var scroll = oram.mem[xofs*2]; // even entries control scroll position
var attrib = oram.mem[xofs*2+1]; // odd entries control the color base
var sl2 = (sl + scroll) & 0xff;
var vramofs = (sl2>>3)<<5; // offset in VRAM
var yy = sl2 & 7; // y offset within tile
var tile = vram.mem[vramofs+xofs];
var color0 = (attrib & 7) << 2;
var addr = gfxBase+(tile<<3)+yy;
var data1 = rom[addr];
var data2 = rom[addr+0x800];
for (var i=0; i<8; i++) {
var bm = 128>>i;
var color = color0 + ((data1&bm)?1:0) + ((data2&bm)?2:0);
pixels[outi] = palette[color];
outi++;
}
}
// draw sprites
for (var sprnum=7; sprnum>=0; sprnum--) {
var base = (sprnum<<2) + 0x40;
var base0 = oram.mem[base];
var sy = 240 - (base0 - (sprnum<3)); // the first three sprites match against y-1
var yy = (sl - sy);
if (yy >= 0 && yy < 16) {
var sx = oram.mem[base+3] + 1; // +1 pixel offset from tiles
if (sx == 0 && !showOffscreenObjects)
continue; // drawn off-buffer
var code = oram.mem[base+1];
var flipx = code & 0x40; // TODO: flipx
if (code & 0x80) // flipy
yy = 15-yy;
code &= 0x3f;
var color0 = (oram.mem[base+2] & 7) << 2;
var addr = gfxBase+(code<<5)+(yy<8?yy:yy+8);
outi = pixofs + sx; //<< 1
var data1 = rom[addr];
var data2 = rom[addr+0x800];
for (var i=0; i<8; i++) {
var bm = 128>>i;
var color = ((data1&bm)?1:0) + ((data2&bm)?2:0);
if (color)
pixels[flipx?(outi+15-i):(outi+i)] = palette[color0 + color];
}
var data1 = rom[addr+8];
var data2 = rom[addr+0x808];
for (var i=0; i<8; i++) {
var bm = 128>>i;
var color = ((data1&bm)?1:0) + ((data2&bm)?2:0);
if (color)
pixels[flipx?(outi+7-i):(outi+i+8)] = palette[color0 + color];
}
}
}
// draw bullets/shells
var shell = 0xff;
var missile = 0xff;
for (var which=0; which<8; which++) {
var sy = oram.mem[0x60 + (which<<2)+1];
if (((sy + sl - (which<3))&0xff) == 0xff) {
if (which != 7)
shell = which;
else
missile = which;
}
}
for (var i=0; i<2; i++) {
which = i ? missile : shell;
if (which != 0xff) {
var sx = 255 - oram.mem[0x60 + (which<<2)+3];
var outi = pixofs+sx-missileOffset;
var col = which == 7 ? 0xffffff00 : 0xffffffff;
for (var j=0; j<missileWidth; j++)
pixels[outi++] = col;
}
}
// draw stars
if (starsEnabled) {
var starx = ((frameCounter + stars[sl & 0xff]) & 0xff);
if ((starx + sl) & 0x10) {
var outi = pixofs + starx;
if ((pixels[outi] & 0xffffff) == 0) {
pixels[outi] = palette[sl & 0x1f];
}
}
}
}
this.getPresets = function() {
return GALAXIAN_PRESETS;
}
var m_protection_state = 0;
var m_protection_result = 0;
function scramble_protection_w(addr,data) {
/*
This is not fully understood; the low 4 bits of port C are
inputs; the upper 4 bits are outputs. Scramble main set always
writes sequences of 3 or more nibbles to the low port and
expects certain results in the upper nibble afterwards.
*/
m_protection_state = (m_protection_state << 4) | (data & 0x0f);
switch (m_protection_state & 0xfff)
{
/* scramble */
case 0xf09: m_protection_result = 0xff; break;
case 0xa49: m_protection_result = 0xbf; break;
case 0x319: m_protection_result = 0x4f; break;
case 0x5c9: m_protection_result = 0x6f; break;
/* scrambls */
case 0x246: m_protection_result ^= 0x80; break;
case 0xb5f: m_protection_result = 0x6f; break;
}
}
function scramble_protection_alt_r() {
var bit = (m_protection_result >> 7) & 1;
return (bit << 5) | ((bit^1) << 7);
}
this.start = function() {
ram = new RAM(0x800);
vram = new RAM(0x400);
oram = new RAM(0x100);
outlatches = new RAM(0x8);
if (options.scramble) {
inputs = [0xff,0xfc,0xf1];
membus = {
read: new AddressDecoder([
[0x0000, 0x3fff, 0, function(a) { return rom ? rom[a] : null; }],
[0x4000, 0x47ff, 0x7ff, function(a) { return ram.mem[a]; }],
// [0x4800, 0x4fff, 0x3ff, function(a) { return vram.mem[a]; }],
// [0x5000, 0x5fff, 0xff, function(a) { return oram.mem[a]; }],
[0x7000, 0x7000, 0, function(a) { watchdog_counter = INITIAL_WATCHDOG; }],
[0x7800, 0x7800, 0, function(a) { watchdog_counter = INITIAL_WATCHDOG; }],
//[0x8000, 0x820f, 0, function(a) { return noise(); }], // TODO: remove
[0x8100, 0x8100, 0, function(a) { return inputs[0]; }],
[0x8101, 0x8101, 0, function(a) { return inputs[1]; }],
[0x8102, 0x8102, 0, function(a) { return inputs[2] | scramble_protection_alt_r(); }],
[0x8202, 0x8202, 0, function(a) { return m_protection_result; }], // scramble (protection)
[0x9100, 0x9100, 0, function(a) { return inputs[0]; }],
[0x9101, 0x9101, 0, function(a) { return inputs[1]; }],
[0x9102, 0x9102, 0, function(a) { return inputs[2] | scramble_protection_alt_r(); }],
[0x9212, 0x9212, 0, function(a) { return m_protection_result; }], // scramble (protection)
//[0, 0xffff, 0, function(a) { console.log(hex(a)); return 0; }]
]),
write: new AddressDecoder([
[0x4000, 0x47ff, 0x7ff, function(a,v) { ram.mem[a] = v; }],
[0x4800, 0x4fff, 0x3ff, function(a,v) { vram.mem[a] = v; }],
[0x5000, 0x5fff, 0xff, function(a,v) { oram.mem[a] = v; }],
[0x6801, 0x6801, 0, function(a,v) { interruptEnabled = v & 1; /*console.log(a,v,cpu.getPC().toString(16));*/ }],
[0x6802, 0x6802, 0, function(a,v) { /* TODO: coin counter */ }],
[0x6803, 0x6803, 0, function(a,v) { /* TODO: backgroundColor = (v & 1) ? 0xFF000056 : 0xFF000000; */ }],
[0x6804, 0x6804, 0, function(a,v) { starsEnabled = v & 1; }],
[0x6808, 0x6808, 0, function(a,v) { missileWidth = v; }], // not on h/w
[0x6809, 0x6809, 0, function(a,v) { missileOffset = v; }], // not on h/w
[0x8202, 0x8202, 0, scramble_protection_w],
//[0x8100, 0x8103, 0, function(a,v){ /* PPI 0 */ }],
//[0x8200, 0x8203, 0, function(a,v){ /* PPI 1 */ }],
//[0, 0xffff, 0, function(a,v) { console.log(hex(a),hex(v)); }]
]),
isContended: function() { return false; },
};
} else {
inputs = [0xe,0x8,0x0];
membus = {
read: new AddressDecoder([
[0x0000, 0x3fff, 0, function(a) { return rom ? rom[a] : null; }],
[0x4000, 0x47ff, 0x3ff, function(a) { return ram.mem[a]; }],
[0x5000, 0x57ff, 0x3ff, function(a) { return vram.mem[a]; }],
[0x5800, 0x5fff, 0xff, function(a) { return oram.mem[a]; }],
[0x6000, 0x6000, 0, function(a) { return inputs[0]; }],
[0x6800, 0x6800, 0, function(a) { return inputs[1]; }],
[0x7000, 0x7000, 0, function(a) { return inputs[2]; }],
[0x7800, 0x7800, 0, function(a) { watchdog_counter = INITIAL_WATCHDOG; }],
]),
write: new AddressDecoder([
[0x4000, 0x47ff, 0x3ff, function(a,v) { ram.mem[a] = v; }],
[0x5000, 0x57ff, 0x3ff, function(a,v) { vram.mem[a] = v; }],
[0x5800, 0x5fff, 0xff, function(a,v) { oram.mem[a] = v; }],
//[0x6004, 0x6007, 0x3, function(a,v) { }], // lfo freq
//[0x6800, 0x6807, 0x7, function(a,v) { }], // sound
//[0x7800, 0x7800, 0x7, function(a,v) { }], // pitch
[0x6000, 0x6003, 0x3, function(a,v) { outlatches.mem[a] = v; }],
[0x7001, 0x7001, 0, function(a,v) { interruptEnabled = v & 1; }],
[0x7004, 0x7004, 0, function(a,v) { starsEnabled = v & 1; }],
]),
isContended: function() { return false; },
};
}
this.readAddress = function(a) {
return (a == 0x7000 || a == 0x7800) ? null : membus.read(a); // ignore watchdog
};
audio = new MasterAudio();
psg1 = new AY38910_Audio(audio);
psg2 = new AY38910_Audio(audio);
iobus = {
read: function(addr) {
return 0;
},
write: function(addr, val) {
if (addr & 0x1) { psg1.selectRegister(val & 0xf); };
if (addr & 0x2) { psg1.setData(val); };
if (addr & 0x4) { psg2.selectRegister(val & 0xf); };
if (addr & 0x8) { psg2.setData(val); };
}
};
cpu = self.newCPU(membus, iobus);
video = new RasterVideo(mainElement,264,264,{rotate:90});
video.create();
var idata = video.getFrameData();
setKeyboardFromMap(video, inputs, keyMap);
pixels = video.getFrameData();
timer = new AnimationTimer(60, function() {
if (!self.isRunning())
return;
var debugCond = self.getDebugCallback();
var targetTstates = cpu.getTstates();
// TODO: get raster position
for (var sl=0; sl<scanlinesPerFrame; sl++) {
drawScanline(pixels, sl);
targetTstates += cpuCyclesPerLine;
if (debugCond) {
while (cpu.getTstates() < targetTstates) {
if (debugCond && debugCond()) { debugCond = null; }
cpu.runFrame(cpu.getTstates() + 1);
}
} else {
cpu.runFrame(targetTstates);
}
}
// visible area is 256x224 (before rotation)
video.updateFrame(0, 0, 0, 0, showOffscreenObjects ? 264 : 256, 264);
frameCounter = (frameCounter + 1) & 0xff;
if (watchdog_counter-- <= 0) {
console.log("WATCHDOG FIRED, PC ", hex(cpu.getPC())); // TODO: alert on video
self.reset();
}
self.restartDebugState();
// NMI interrupt @ 0x66
if (interruptEnabled) { cpu.nonMaskableInterrupt(); }
});
}
var bitcolors = [
0x000021, 0x000047, 0x000097, // red
0x002100, 0x004700, 0x009700, // green
0x510000, 0xae0000 // blue
];
this.loadROM = function(title, data) {
rom = padBytes(data, romSize);
palette = new Uint32Array(new ArrayBuffer(32*4));
for (var i=0; i<32; i++) {
var b = rom[palBase+i];
palette[i] = 0xff000000;
for (var j=0; j<8; j++)
if (((1<<j) & b))
palette[i] += bitcolors[j];
}
self.reset();
}
this.loadState = function(state) {
cpu.loadState(state.c);
ram.mem.set(state.b);
vram.mem.set(state.bv);
oram.mem.set(state.bo);
watchdog_counter = state.wdc;
interruptEnabled = state.ie;
starsEnabled = state.se;
frameCounter = state.fc;
inputs[0] = state.in0;
inputs[1] = state.in1;
inputs[2] = state.in2;
}
this.saveState = function() {
return {
c:self.getCPUState(),
b:ram.mem.slice(0),
bv:vram.mem.slice(0),
bo:oram.mem.slice(0),
fc:frameCounter,
ie:interruptEnabled,
se:starsEnabled,
wdc:watchdog_counter,
in0:inputs[0],
in1:inputs[1],
in2:inputs[2],
};
}
this.getCPUState = function() {
return cpu.saveState();
}
this.isRunning = function() {
return timer && timer.isRunning();
}
this.pause = function() {
timer.stop();
audio.stop();
}
this.resume = function() {
timer.start();
audio.start();
}
this.reset = function() {
cpu.reset();
//audio.reset();
if (!this.getDebugCallback()) cpu.setTstates(0); // TODO?
watchdog_counter = INITIAL_WATCHDOG;
}
}
var GalaxianScramblePlatform = function(mainElement) {
var self = this;
this.__proto__ = new GalaxianPlatform(mainElement, {
romSize: 0x5020,
gfxBase: 0x4000,
palBase: 0x5000,
scramble: true,
keyMap: SCRAMBLE_KEYCODE_MAP,
missileWidth: 1,
missileOffset: 6,
});
}
PLATFORMS['galaxian'] = GalaxianPlatform;
PLATFORMS['galaxian-scramble'] = GalaxianScramblePlatform;