yuzu-emu/FasTC
1
0
Fork 0
mirror of https://github.com/yuzu-emu/FasTC.git synced 2024-11-28 03:44:18 +01:00
Code Issues Packages Projects Releases Wiki Activity

Another bug fix.

Browse Source 
In the previous commit, we simply accomodated for alpha errors when compressing single color partitions. In fact, the issue was a bit more greivous: we weren't computing the proper error term at all! This fixed that function so that we emphasize the error metrics induced by *squaring* the error in each channel and then returning that as a measurement of the acceptability of using a single color compression for that partition.
This commit is contained in:
Pavel Krajcevski 2013-04-08 16:44:15 -04:00
parent ff18e8f33e
commit d23125e14c
1 changed files with 14 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
BPTCEncoder/src/BC7Compressor.cpp
View File

@ -346,14 +346,14 @@ double BC7CompressionMode::CompressSingleColor(const RGBAVector &p, RGBAVector &
const uint32 pixel = p.ToPixel();
uint32 bestDist = 0xFF;
float bestError = FLT_MAX;
bestPbitCombo = -1;
for(int pbi = 0; pbi < GetNumPbitCombos(); pbi++) {
const int *pbitCombo = GetPBitCombo(pbi);
uint32 dist = 0x0;
uint32 dist[4] = { 0x0, 0x0, 0x0, 0x0 };
uint32 bestValI[kNumColorChannels] = { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
uint32 bestValJ[kNumColorChannels] = { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
@ -365,7 +365,7 @@ double BC7CompressionMode::CompressSingleColor(const RGBAVector &p, RGBAVector &
// If we don't handle this channel, then it must be the full value (alpha)
if(nBits == 0) {
bestValI[ci] = bestValJ[ci] = 0xFF;
dist = std::max(dist, (uint32)((uint8)0xFF - val));
dist[ci] = std::max(dist[ci], (uint32)((uint8)0xFF - val));
continue;
}
@ -417,11 +417,18 @@ double BC7CompressionMode::CompressSingleColor(const RGBAVector &p, RGBAVector &
}
}
dist = std::max(bestChannelDist, dist);
dist[ci] = std::max(bestChannelDist, dist[ci]);
}
if(dist < bestDist) {
bestDist = dist;
const float *errorWeights = BC7C::GetErrorMetric();
float error = 0.0;
for(int i = 0; i < kNumColorChannels; i++) {
float e = float(dist[i]) * errorWeights[i];
error += e * e;
}
if(error < bestError) {
bestError = error;
bestPbitCombo = pbi;
for(uint32 ci = 0; ci < kNumColorChannels; ci++) {
@ -431,7 +438,7 @@ double BC7CompressionMode::CompressSingleColor(const RGBAVector &p, RGBAVector &
}
}
return bestDist;
return bestError;
}
// Fast random number generator. See more information at