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Reduce deep nesting in gfx/pal_packing.cpp

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Rangi42
2025-07-29 13:45:19 -04:00
parent 6d05de9d4d
commit d388a60daa
1 changed files with 92 additions and 108 deletions
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200
src/gfx/pal_packing.cpp
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@@ -307,42 +307,38 @@ static void decant(std::vector<AssignedSets> &assignments, std::vector<ColorSet>
// We do this by adding the first available color set, and then looking for palettes with
// common colors. (As an optimization, we know we can skip palettes already scanned.)
std::vector<bool> processed(from.nbColorSets(), false);
std::unordered_set<uint16_t> colors;
std::vector<size_t> members;
while (true) {
auto iter = std::find(RANGE(processed), true);
if (iter == processed.end()) { // Processed everything!
break;
}
for (std::vector<bool>::iterator iter;
(iter = std::find(RANGE(processed), true)) != processed.end();) {
auto attrs = from.begin();
std::advance(attrs, iter - processed.begin());
std::unordered_set<uint16_t> colors(RANGE(colorSets[attrs->colorSetIndex]));
std::vector<size_t> members = {static_cast<size_t>(iter - processed.begin())};
*iter = true; // Mark the first color set as processed
// Build up the "component"...
colors.clear();
members.clear();
assume(members.empty()); // Compiler optimization hint
do {
ColorSet const &colorSet = colorSets[attrs->colorSetIndex];
// If this is the first color set, or if at least one color matches, add it
if (members.empty()
|| std::find_first_of(RANGE(colors), RANGE(colorSet)) != colors.end()) {
for (; ++iter != processed.end(); ++attrs) {
// If at least one color matches, add it
if (ColorSet const &colorSet = colorSets[attrs->colorSetIndex];
std::find_first_of(RANGE(colors), RANGE(colorSet)) != colors.end()) {
colors.insert(RANGE(colorSet));
members.push_back(iter - processed.begin());
*iter = true; // Mark that color set as processed
}
++attrs;
} while (++iter != processed.end());
}
if (to.combinedVolume(RANGE(colors)) <= options.maxOpaqueColors()) {
// Iterate through the component's color sets, and transfer them
auto member = from.begin();
size_t curIndex = 0;
for (size_t index : members) {
std::advance(member, index - curIndex);
curIndex = index;
to.assign(std::move(*member));
from.remove(member); // Removing does not shift elements, so it's cheap
}
if (to.combinedVolume(RANGE(colors)) > options.maxOpaqueColors()) {
continue;
}
// Iterate through the component's color sets, and transfer them
auto member = from.begin();
size_t curIndex = 0;
for (size_t index : members) {
std::advance(member, index - curIndex);
curIndex = index;
to.assign(std::move(*member));
from.remove(member); // Removing does not shift elements, so it's cheap
}
}
});
@@ -383,12 +379,13 @@ std::tuple<std::vector<size_t>, size_t> overloadAndRemove(std::vector<ColorSet>
);
}
// Begin with all color sets queued up for insertion
std::queue<ColorSetAttrs> queue(std::deque<ColorSetAttrs>(RANGE(sortedColorSetIDs)));
// Begin with no pages
std::vector<AssignedSets> assignments{};
std::vector<AssignedSets> assignments;
for (; !queue.empty(); queue.pop()) {
// Begin with all color sets queued up for insertion
for (std::queue<ColorSetAttrs> queue(std::deque<ColorSetAttrs>(RANGE(sortedColorSetIDs)));
!queue.empty();
queue.pop()) {
ColorSetAttrs const &attrs = queue.front(); // Valid until the `queue.pop()`
options.verbosePrint(Options::VERB_TRACE, "Handling color set %zu\n", attrs.colorSetIndex);
@@ -428,91 +425,78 @@ std::tuple<std::vector<size_t>, size_t> overloadAndRemove(std::vector<ColorSet>
bestPalIndex
);
assignments.emplace_back(colorSets, std::move(attrs));
} else {
continue;
}
options.verbosePrint(
Options::VERB_TRACE,
"Assigning color set %zu to palette %zu\n",
attrs.colorSetIndex,
bestPalIndex
);
AssignedSets &bestPal = assignments[bestPalIndex];
// Add the color to that palette
bestPal.assign(std::move(attrs));
auto compareEfficiency = [&](ColorSetAttrs const &attrs1, ColorSetAttrs const &attrs2) {
ColorSet const &colorSet1 = colorSets[attrs1.colorSetIndex];
ColorSet const &colorSet2 = colorSets[attrs2.colorSetIndex];
size_t size1 = colorSet1.size();
size_t size2 = colorSet2.size();
uint32_t relSize1 = bestPal.relSizeOf(colorSet1);
uint32_t relSize2 = bestPal.relSizeOf(colorSet2);
options.verbosePrint(
Options::VERB_TRACE,
"Assigning color set %zu to palette %zu\n",
attrs.colorSetIndex,
bestPalIndex
" Color sets %zu <=> %zu: Efficiency: %zu / %" PRIu32 " <=> %zu / "
"%" PRIu32 "\n",
attrs1.colorSetIndex,
attrs2.colorSetIndex,
size1,
relSize1,
size2,
relSize2
);
AssignedSets &bestPal = assignments[bestPalIndex];
// Add the color to that palette
bestPal.assign(std::move(attrs));
// If this overloads the palette, get it back to normal (if possible)
while (bestPal.volume() > options.maxOpaqueColors()) {
options.verbosePrint(
Options::VERB_TRACE,
"Palette %zu is overloaded! (%zu > %" PRIu8 ")\n",
bestPalIndex,
bestPal.volume(),
options.maxOpaqueColors()
);
// This comparison is algebraically equivalent to
// `size1 / relSize1 <=> size2 / relSize2`,
// but without potential precision loss from floating-point division.
size_t efficiency1 = size1 * relSize2;
size_t efficiency2 = size2 * relSize1;
return (efficiency1 > efficiency2) - (efficiency1 < efficiency2);
};
// Look for a color set minimizing "efficiency" (size / rel_size)
auto [minEfficiencyIter, maxEfficiencyIter] = std::minmax_element(
RANGE(bestPal),
[&bestPal, &colorSets](ColorSetAttrs const &lhs, ColorSetAttrs const &rhs) {
ColorSet const &lhsColorSet = colorSets[lhs.colorSetIndex];
ColorSet const &rhsColorSet = colorSets[rhs.colorSetIndex];
size_t lhsSize = lhsColorSet.size();
size_t rhsSize = rhsColorSet.size();
uint32_t lhsRelSize = bestPal.relSizeOf(lhsColorSet);
uint32_t rhsRelSize = bestPal.relSizeOf(rhsColorSet);
// If this overloads the palette, get it back to normal (if possible)
while (bestPal.volume() > options.maxOpaqueColors()) {
options.verbosePrint(
Options::VERB_TRACE,
"Palette %zu is overloaded! (%zu > %" PRIu8 ")\n",
bestPalIndex,
bestPal.volume(),
options.maxOpaqueColors()
);
options.verbosePrint(
Options::VERB_TRACE,
" Color sets %zu <=> %zu: Efficiency: %zu / %" PRIu32 " <=> %zu / "
"%" PRIu32 "\n",
lhs.colorSetIndex,
rhs.colorSetIndex,
lhsSize,
lhsRelSize,
rhsSize,
rhsRelSize
);
// This comparison is algebraically equivalent to
// `lhsSize / lhsRelSize < rhsSize / rhsRelSize`,
// but without potential precision loss from floating-point division.
return lhsSize * rhsRelSize < rhsSize * lhsRelSize;
}
);
// Look for a color set minimizing "efficiency" (size / relSize)
auto [minEfficiencyIter, maxEfficiencyIter] = std::minmax_element(
RANGE(bestPal),
[&compareEfficiency](ColorSetAttrs const &lhs, ColorSetAttrs const &rhs) {
return compareEfficiency(lhs, rhs) < 0;
}
);
// All efficiencies are identical iff min equals max
ColorSet const &minColorSet = colorSets[minEfficiencyIter->colorSetIndex];
ColorSet const &maxColorSet = colorSets[maxEfficiencyIter->colorSetIndex];
size_t minSize = minColorSet.size();
size_t maxSize = maxColorSet.size();
uint32_t minRelSize = bestPal.relSizeOf(minColorSet);
uint32_t maxRelSize = bestPal.relSizeOf(maxColorSet);
options.verbosePrint(
Options::VERB_TRACE,
" Color sets %zu <= %zu: Efficiency: %zu / %" PRIu32 " <= %zu / %" PRIu32 "\n",
minEfficiencyIter->colorSetIndex,
maxEfficiencyIter->colorSetIndex,
minSize,
minRelSize,
maxSize,
maxRelSize
);
// This comparison is algebraically equivalent to
// `maxSize / maxRelSize == minSize / minRelSize`,
// but without potential precision loss from floating-point division.
if (maxSize * minRelSize == minSize * maxRelSize) {
options.verbosePrint(Options::VERB_TRACE, " All efficiencies are identical\n");
break;
}
// Remove the color set with minimal efficiency
options.verbosePrint(
Options::VERB_TRACE,
" Removing color set %zu\n",
minEfficiencyIter->colorSetIndex
);
queue.emplace(std::move(*minEfficiencyIter));
queue.back().banFrom(bestPalIndex); // Ban it from this palette
bestPal.remove(minEfficiencyIter);
// All efficiencies are identical iff min equals max
if (compareEfficiency(*minEfficiencyIter, *maxEfficiencyIter) == 0) {
options.verbosePrint(Options::VERB_TRACE, " All efficiencies are identical\n");
break;
}
// Remove the color set with minimal efficiency
options.verbosePrint(
Options::VERB_TRACE, " Removing color set %zu\n", minEfficiencyIter->colorSetIndex
);
queue.emplace(std::move(*minEfficiencyIter));
queue.back().banFrom(bestPalIndex); // Ban it from this palette
bestPal.remove(minEfficiencyIter);
}
}