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DS GX: Combine linear interpolation functions

This commit is contained in:
Vicki Pfau 2017-03-01 10:59:19 -08:00
parent d6cf1d2fe1
commit 619583775d
1 changed files with 29 additions and 35 deletions
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64
src/ds/gx/software.c
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@ -27,6 +27,17 @@ static void _expandColor(uint16_t c15, int8_t* r, int8_t* g, int8_t* b) {
*b = ((c15 >> 9) & 0x3E) | 1;
}
static color_t _finishColor(int8_t r, int8_t g, int8_t b) {
#ifndef COLOR_16_BIT
color_t rgb = (r << 2) & 0xF8;
rgb |= (g << 10) & 0xF800;
rgb |= (b << 18) & 0xF80000;
return rgb;
#else
#error Unsupported color depth
#endif
}
static int _edgeSort(const void* a, const void* b) {
const struct DSGXSoftwareEdge* ea = a;
const struct DSGXSoftwareEdge* eb = b;
@ -88,20 +99,20 @@ static int _spanSort(const void* a, const void* b) {
if (sa->ep[0].x > sb->ep[0].x) {
return -1;
}
if (sa->ep[1].x < sb->ep[1].x) {
if (sa->ep[0].w < sb->ep[0].w) {
return 1;
}
if (sa->ep[1].x > sb->ep[1].x) {
if (sa->ep[0].w > sb->ep[0].w) {
return -1;
}
return 0;
}
static color_t _lerpColor(const struct DSGXSoftwareSpan* span, unsigned x) {
static void _lerpEndpoint(const struct DSGXSoftwareSpan* span, struct DSGXSoftwareEndpoint* ep, unsigned x) {
int64_t width = span->ep[1].x - span->ep[0].x;
int64_t xw = ((uint64_t) x << 12) - span->ep[0].x;
if (!width) {
return 0; // TODO?
return; // TODO?
}
// Clamp to bounds
if (xw < 0) {
@ -112,38 +123,19 @@ static color_t _lerpColor(const struct DSGXSoftwareSpan* span, unsigned x) {
int32_t w0 = span->ep[0].w;
int32_t w1 = span->ep[1].w;
int32_t w = ((int64_t) (w1 - w0) * xw) / width + w0;
ep->w = w;
uint64_t r = ((span->ep[1].cr * (int64_t) w1 - span->ep[0].cr * (int64_t) w0) * xw) / width + span->ep[0].cr * (int64_t) w0;
uint64_t g = ((span->ep[1].cg * (int64_t) w1 - span->ep[0].cg * (int64_t) w0) * xw) / width + span->ep[0].cg * (int64_t) w0;
uint64_t b = ((span->ep[1].cb * (int64_t) w1 - span->ep[0].cb * (int64_t) w0) * xw) / width + span->ep[0].cb * (int64_t) w0;
r /= w;
g /= w;
b /= w;
#ifndef COLOR_16_BIT
color_t rgb = (r << 2) & 0xF8;
rgb |= (g << 10) & 0xF800;
rgb |= (b << 18) & 0xF80000;
return rgb;
#else
#error Unsupported color depth
#endif
}
ep->cr = r / w;
ep->cg = g / w;
ep->cb = b / w;
static int32_t _lerpDepth(const struct DSGXSoftwareSpan* span, unsigned x) {
int64_t width = span->ep[1].x - span->ep[0].x;
int64_t xw = ((uint64_t) x << 12) - span->ep[0].x;
if (!width) {
return 0; // TODO?
}
// Clamp to bounds
if (xw < 0) {
xw = 0;
} else if (xw > width) {
xw = width;
}
int32_t w0 = span->ep[0].w;
int32_t w1 = span->ep[1].w;
return ((int64_t) (w1 - w0) * xw) / width + w0;
int32_t s = ((span->ep[1].s * (int64_t) w1 - span->ep[0].s * (int64_t) w0) * xw) / width + span->ep[0].s * (int64_t) w0;
int32_t t = ((span->ep[1].t * (int64_t) w1 - span->ep[0].t * (int64_t) w0) * xw) / width + span->ep[0].t * (int64_t) w0;
ep->s = s / w;
ep->t = t / w;
}
void DSGXSoftwareRendererCreate(struct DSGXSoftwareRenderer* renderer) {
@ -309,6 +301,7 @@ static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int
}
for (i = 0; i < DS_VIDEO_HORIZONTAL_PIXELS; ++i) {
struct DSGXSoftwareSpan* span = NULL;
struct DSGXSoftwareEndpoint ep;
int32_t depth = INT32_MIN;
if (i >= nextSpanX) {
size_t nextSpanId = DSGXSoftwareSpanListSize(&softwareRenderer->activeSpans);
@ -330,9 +323,9 @@ static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int
struct DSGXSoftwareSpan* testSpan = DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, nextSpanId - 1);
while (i > (uint32_t) (testSpan->ep[0].x >> 12)) {
if (i <= (uint32_t) (testSpan->ep[1].x >> 12)) {
int32_t newDepth = _lerpDepth(testSpan, i);
if (newDepth > depth) {
depth = newDepth;
_lerpEndpoint(testSpan, &ep, i);
if (ep.w > depth) {
depth = ep.w;
span = testSpan;
}
}
@ -345,7 +338,8 @@ static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int
}
}
if (span) {
scanline[i] = _lerpColor(span, i);
_lerpEndpoint(span, &ep, i);
scanline[i] = _finishColor(ep.cr, ep.cg, ep.cb);
} else {
scanline[i] = FLAG_UNWRITTEN; // TODO
}