bsnes/higan/gba/ppu/screen.cpp

90 lines
3.0 KiB
C++

auto PPU::render_forceblank() -> void {
uint32* line = output + regs.vcounter * 240;
for(auto x : range(240)) line[x] = 0x7fff;
}
auto PPU::render_screen() -> void {
uint32* line = output + regs.vcounter * 240;
if(regs.bg[0].control.mosaic) render_mosaic_background(BG0);
if(regs.bg[1].control.mosaic) render_mosaic_background(BG1);
if(regs.bg[2].control.mosaic) render_mosaic_background(BG2);
if(regs.bg[3].control.mosaic) render_mosaic_background(BG3);
render_mosaic_object();
for(auto x : range(240)) {
Registers::WindowFlags flags;
flags = ~0; //enable all layers if no windows are enabled
//determine active window
if(regs.control.enablewindow[In0] || regs.control.enablewindow[In1] || regs.control.enablewindow[Obj]) {
flags = (uint8)regs.windowflags[Out];
if(regs.control.enablewindow[Obj] && windowmask[Obj][x]) flags = (uint8)regs.windowflags[Obj];
if(regs.control.enablewindow[In1] && windowmask[In1][x]) flags = (uint8)regs.windowflags[In1];
if(regs.control.enablewindow[In0] && windowmask[In0][x]) flags = (uint8)regs.windowflags[In0];
}
//priority sorting: find topmost two pixels
uint a = 5, b = 5;
for(int p = 3; p >= 0; p--) {
for(int l = 5; l >= 0; l--) {
if(layer[l][x].enable && layer[l][x].priority == p && flags.enable[l]) {
b = a;
a = l;
}
}
}
auto& above = layer[a];
auto& below = layer[b];
bool blendabove = regs.blend.control.above[a];
bool blendbelow = regs.blend.control.below[b];
uint color = above[x].color;
auto eva = min(16u, (unsigned)regs.blend.eva);
auto evb = min(16u, (unsigned)regs.blend.evb);
auto evy = min(16u, (unsigned)regs.blend.evy);
//perform blending, if needed
if(flags.enable[SFX] == false) {
} else if(above[x].translucent && blendbelow) {
color = blend(above[x].color, eva, below[x].color, evb);
} else if(regs.blend.control.mode == 1 && blendabove && blendbelow) {
color = blend(above[x].color, eva, below[x].color, evb);
} else if(regs.blend.control.mode == 2 && blendabove) {
color = blend(above[x].color, 16 - evy, 0x7fff, evy);
} else if(regs.blend.control.mode == 3 && blendabove) {
color = blend(above[x].color, 16 - evy, 0x0000, evy);
}
//output pixel
line[x] = color;
}
}
auto PPU::render_window(uint w) -> void {
uint y = regs.vcounter;
uint y1 = regs.window[w].y1, y2 = regs.window[w].y2;
uint x1 = regs.window[w].x1, x2 = regs.window[w].x2;
if(y2 < y1 || y2 > 160) y2 = 160;
if(x2 < x1 || x2 > 240) x2 = 240;
if(y >= y1 && y < y2) {
for(uint x = x1; x < x2; x++) {
windowmask[w][x] = true;
}
}
}
auto PPU::blend(uint above, uint eva, uint below, uint evb) -> uint {
uint5 ar = above >> 0, ag = above >> 5, ab = above >> 10;
uint5 br = below >> 0, bg = below >> 5, bb = below >> 10;
uint r = (ar * eva + br * evb) >> 4;
uint g = (ag * eva + bg * evb) >> 4;
uint b = (ab * eva + bb * evb) >> 4;
return min(31, r) << 0 | min(31, g) << 5 | min(31, b) << 10;
}