bsnes/higan/ms/vdp/vdp.cpp

122 lines
2.6 KiB
C++

#include <ms/ms.hpp>
namespace MasterSystem {
VDP vdp;
#include "io.cpp"
#include "background.cpp"
#include "sprite.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;
}
background.scanline();
sprite.scanline();
//684 clocks/scanline
uint y = io.vcounter;
if(y < vlines()) {
uint32* screen = buffer + (24 + y) * 256;
for(uint x : range(256)) {
background.run();
sprite.run();
step(2);
uint12 color = palette(io.backdropColor);
if(background.output.color && (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(x <= 7 && io.leftClip) color = palette(io.backdropColor);
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 == 262) {
io.vcounter = 0;
}
}
cpu.setINT((io.lineInterrupts && io.intLine) || (io.frameInterrupts && io.intFrame));
Thread::step(1);
synchronize(cpu);
}
}
auto VDP::refresh() -> void {
if(system.model() == 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(system.model() == Model::GameGear) {
Emulator::video.refresh(buffer + 48 * 256 + 48, 256 * sizeof(uint32), 160, 144);
}
}
auto VDP::vlines() -> uint {
if(io.lines240) return 240;
if(io.lines224) return 224;
return 192;
}
auto VDP::vblank() -> bool {
return io.vcounter >= vlines();
}
auto VDP::power() -> void {
create(VDP::Enter, system.colorburst() * 15.0 / 5.0);
memory::fill(&buffer, sizeof(buffer));
memory::fill(&io, sizeof(IO));
background.power();
sprite.power();
}
auto VDP::palette(uint5 index) -> uint12 {
if(system.model() == Model::MasterSystem) {
return cram[index];
}
if(system.model() == Model::GameGear) {
return cram[index * 2 + 0] << 0 | cram[index * 2 + 1] << 8;
}
return 0;
}
}