bsnes/higan/ms/vdp/vdp.cpp

133 lines
3.2 KiB
C++

#include <ms/ms.hpp>
namespace MasterSystem {
VDP vdp;
#include "io.cpp"
#include "background.cpp"
#include "sprite.cpp"
#include "serialization.cpp"
auto VDP::Enter() -> void {
while(true) scheduler.synchronize(), vdp.main();
}
auto VDP::main() -> void {
if(io.vcounter <= vlines()) {
if(io.lcounter-- == 0) {
io.lcounter = io.lineCounter;
io.intLine = 1;
}
} else {
io.lcounter = io.lineCounter;
}
if(io.vcounter == vlines() + 1) {
io.intFrame = 1;
}
//684 clocks/scanline
uint y = io.vcounter;
sprite.setup(y);
if(y < vlines()) {
uint32* screen = buffer + (24 + y) * 256;
for(uint x : range(256)) {
background.run(x, y);
sprite.run(x, y);
step(2);
uint12 color = palette(16 | io.backdropColor);
if(!io.leftClip || x >= 8) {
if(background.output.priority || !sprite.output.color) {
color = palette(background.output.palette << 4 | background.output.color);
} else if(sprite.output.color) {
color = palette(16 | sprite.output.color);
}
}
if(!io.displayEnable) color = 0;
*screen++ = color;
}
} else {
//Vblank
step(512);
}
step(172);
if(io.vcounter == 240) scheduler.exit(Scheduler::Event::Frame);
}
auto VDP::step(uint clocks) -> void {
while(clocks--) {
if(++io.hcounter == 684) {
io.hcounter = 0;
if(++io.vcounter == (Region::NTSC() ? 262 : 312)) {
io.vcounter = 0;
}
}
cpu.setINT((io.lineInterrupts && io.intLine) || (io.frameInterrupts && io.intFrame));
Thread::step(1);
synchronize(cpu);
}
}
auto VDP::refresh() -> void {
if(Model::ColecoVision() || Model::SG1000() || Model::SC3000()) {
uint32* screen = buffer;
screen += 24 * 256;
Emulator::video.refresh(screen, 256 * sizeof(uint32), 256, 192);
}
if(Model::MasterSystem()) {
//center the video output vertically in the viewport
uint32* screen = buffer;
if(vlines() == 224) screen += 16 * 256;
if(vlines() == 240) screen += 24 * 256;
Emulator::video.refresh(screen, 256 * sizeof(uint32), 256, 240);
}
if(Model::GameGear()) {
Emulator::video.refresh(buffer + 48 * 256 + 48, 256 * sizeof(uint32), 160, 144);
}
}
auto VDP::vlines() -> uint {
switch(io.mode) {
default: return 192;
case 0b1011: return 224;
case 0b1110: return 240;
}
}
auto VDP::vblank() -> bool {
return io.vcounter >= vlines();
}
auto VDP::power() -> void {
create(VDP::Enter, system.colorburst() * 15.0 / 5.0);
memory::fill<uint32>(buffer, 256 * 264);
for(auto& byte : vram) byte = 0x00;
for(auto& byte : cram) byte = 0x00;
io = {};
background.power();
sprite.power();
}
auto VDP::palette(uint5 index) -> uint12 {
if(Model::ColecoVision() || Model::SG1000() || Model::SC3000()) return index.bits(0,3);
//Master System and Game Gear approximate TMS9918A colors by converting to RGB6 palette colors
static uint6 palette[16] = {
0x00, 0x00, 0x08, 0x0c, 0x10, 0x30, 0x01, 0x3c,
0x02, 0x03, 0x05, 0x0f, 0x04, 0x33, 0x15, 0x3f,
};
if(!io.mode.bit(3)) return palette[index.bits(0,3)];
if(Model::MasterSystem()) return cram[index];
if(Model::GameGear()) return cram[index * 2 + 0] << 0 | cram[index * 2 + 1] << 8;
return 0;
}
}