ShuriZma
/
mgba
mirror of https://github.com/mgba-emu/mgba.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

DS GX: Start on alpha

This commit is contained in:
Vicki Pfau 2017-03-04 16:01:43 -08:00
parent 1ed7db5c9c
commit 4fecedb42a
1 changed files with 49 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
src/ds/gx/software.c
View File

@ -40,6 +40,36 @@ static color_t _finishColor(uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
#endif
}
static unsigned _mix32(int weightA, unsigned colorA, int weightB, unsigned colorB) {
unsigned c = 0;
unsigned a, b;
#ifdef COLOR_16_BIT
#error Unsupported color depth
#else
a = colorA & 0xFF;
b = colorB & 0xFF;
c |= ((a * weightA + b * weightB) / 32) & 0x1FF;
if (c & 0x00000100) {
c = 0x000000FF;
}
a = colorA & 0xFF00;
b = colorB & 0xFF00;
c |= ((a * weightA + b * weightB) / 32) & 0x1FF00;
if (c & 0x00010000) {
c = (c & 0x000000FF) | 0x0000FF00;
}
a = colorA & 0xFF0000;
b = colorB & 0xFF0000;
c |= ((a * weightA + b * weightB) / 32) & 0x1FF0000;
if (c & 0x01000000) {
c = (c & 0x0000FFFF) | 0x00FF0000;
}
#endif
return c;
}
static color_t _lookupColor(struct DSGXSoftwareEndpoint* ep, struct DSGXSoftwarePolygon* poly) {
// TODO: Optimize
uint16_t texel;
@ -444,7 +474,8 @@ static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int
struct DSGXSoftwareEndpoint ep;
_lerpEndpoint(span, &ep, x);
color_t color = _lookupColor(&ep, span->poly);
if (color & 0xF8000000) {
unsigned a = color >> 27;
if (a == 0x1F || (a && !(scanline[x] & 0xF8000000))) {
// TODO: Alpha
if (softwareRenderer->wSort) {
if (ep.w < softwareRenderer->depthBuffer[x]) {
@ -457,6 +488,23 @@ static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int
scanline[x] = color;
}
}
} else if (a) {
// TODO: Disable alpha?
color = _mix32(a, color, 0x1F - a, scanline[x]);
if (scanline[x] >> 27 > a) {
a = scanline[x] >> 27;
}
color |= a << 27;
scanline[x] = color;
if (softwareRenderer->wSort) {
if (ep.w < softwareRenderer->depthBuffer[x]) {
softwareRenderer->depthBuffer[x] = ep.w;
}
} else {
if (ep.z < softwareRenderer->depthBuffer[x]) {
softwareRenderer->depthBuffer[x] = ep.z;
}
}
}
}
}