cpp/openttd-patchpack/source Changeset - r24463:5d1832e07fa7

Changeset - r24463:5d1832e07fa7

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dP - 5 years ago 2020-01-25 21:53:16
dp@dpointer.org

Feature #7962: Significantly improve sprite sorter performance

3 files changed with 228 insertions and 90 deletions:

src/viewport.cpp

110

src/viewport_sprite_sorter.h

src/viewport_sprite_sorter_sse4.cpp

117

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src/viewport.cpp

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@@ @@ -89,7 +89,9 @@ @@
 #include "network/network_func.h"
 #include "framerate_type.h"
 #include <forward_list>
 #include <map>
 #include <stack>
 #include "table/strings.h"
 #include "table/string_colours.h"
@@ @@ -726,7 +728,6 @@ void AddSortableSpriteToDraw(SpriteID im @@
 	ps.zmin = z + bb_offset_z;
 	ps.zmax = z + max(bb_offset_z, dz) - 1;
 	ps.comparison_done = false;
 	ps.first_child = -1;
 	_vd.last_child = &ps.first_child;
@@ @@ -1498,64 +1499,127 @@ static bool ViewportSortParentSpritesChe @@
 	return true;
+}
 /** Sort parent sprites pointer array */
+/** Sort parent sprites pointer array replicating the way original sorter did it. */
 static void ViewportSortParentSprites(ParentSpriteToSortVector *psdv)
+{
 	auto psdvend = psdv->end();
 	auto psd = psdv->begin();
 	while (psd != psdvend) {
 		ParentSpriteToDraw *ps = *psd;
 		if (ps->comparison_done) {
 			psd++;
 	if (psdv->size() < 2) return;
 	/* We rely on sprites being, for the most part, already ordered.
 	 * So we don't need to move many of them and can keep track of their
 	 * order efficiently by using stack. We always move sprites to the front
 	 * of the current position, i.e. to the top of the stack.
 	 * Also use special constants to indicate sorting state without
 	 * adding extra fields to ParentSpriteToDraw structure.
 	 */
 	const uint32 ORDER_COMPARED = UINT32_MAX; // Sprite was compared but we still need to compare the ones preceding it
 	const uint32 ORDER_RETURNED = UINT32_MAX - 1; // Makr sorted sprite in case there are other occurrences of it in the stack
 	std::stack<ParentSpriteToDraw *> sprite_order;
 	uint32 next_order = 0;
 	std::forward_list<std::pair<int64, ParentSpriteToDraw *>> sprite_list;  // We store sprites in a list sorted by xmin+ymin
 	/* Initialize sprite list and order. */
 	for (auto p = psdv->rbegin(); p != psdv->rend(); p++) {
 		sprite_list.push_front(std::make_pair((*p)->xmin + (*p)->ymin, *p));
 		sprite_order.push(*p);
 		(*p)->order = next_order++;
+	}
 	sprite_list.sort();
 	std::vector<ParentSpriteToDraw*> preceding;  // Temporarily stores sprites that precede current and their position in the list
 	auto preceding_prev = sprite_list.begin(); // Store iterator in case we need to delete a single preciding sprite
 	auto out = psdv->begin();  // Iterator to output sorted sprites
 	while (!sprite_order.empty()) {
 		auto s = sprite_order.top();
 		sprite_order.pop();
 		/* Sprite is already sorted, ignore it. */
 		if (s->order == ORDER_RETURNED) continue;
 		/* Sprite was already compared, just need to output it. */
 		if (s->order == ORDER_COMPARED) {
 			*(out++) = s;
 			s->order = ORDER_RETURNED;
 			continue;
+		}
 		ps->comparison_done = true;
 		for (auto psd2 = psd + 1; psd2 != psdvend; psd2++) {
 			ParentSpriteToDraw *ps2 = *psd2;
 			if (ps2->comparison_done) continue;
 			/* Decide which comparator to use, based on whether the bounding
 			 * boxes overlap
 			 */
 			if (ps->xmax >= ps2->xmin && ps->xmin <= ps2->xmax && // overlap in X?
 					ps->ymax >= ps2->ymin && ps->ymin <= ps2->ymax && // overlap in Y?
 					ps->zmax >= ps2->zmin && ps->zmin <= ps2->zmax) { // overlap in Z?
 				/* Use X+Y+Z as the sorting order, so sprites closer to the bottom of
 				 * the screen and with higher Z elevation, are drawn in front.
 				 * Here X,Y,Z are the coordinates of the "center of mass" of the sprite,
 				 * i.e. X=(left+right)/2, etc.
 				 * However, since we only care about order, don't actually divide / 2
 				 */
 				if (ps->xmin + ps->xmax + ps->ymin + ps->ymax + ps->zmin + ps->zmax <=
 						ps2->xmin + ps2->xmax + ps2->ymin + ps2->ymax + ps2->zmin + ps2->zmax) {
 					continue;
+				}
 			} else {
 				/* We only change the order, if it is definite.
 				 * I.e. every single order of X, Y, Z says ps2 is behind ps or they overlap.
 				 * That is: If one partial order says ps behind ps2, do not change the order.
 				 */
 				if (ps->xmax < ps2->xmin ||
 						ps->ymax < ps2->ymin ||
 						ps->zmax < ps2->zmin) {
 		preceding.clear();
 		/* We only need sprites with xmin <= s->xmax && ymin <= s->ymax && zmin <= s->zmax
 		 * So by iterating sprites with xmin + ymin <= s->xmax + s->ymax
 		 * we get all we need and some more that we filter out later.
 		 * We don't include zmin into the sum as there are usually more neighbors on x and y than z
 		 * so including it will actually increase the amount of false positives.
 		 * Also min coordinates can be > max so using max(xmin, xmax) + max(ymin, ymax)
 		 * to ensure that we iterate the current sprite as we need to remove it from the list.
 		 */
 		auto ssum = max(s->xmax, s->xmin) + max(s->ymax, s->ymin);
 		auto prev = sprite_list.before_begin();
 		auto x = sprite_list.begin();
 		while (x != sprite_list.end() && ((*x).first <= ssum)) {
 			auto p = (*x).second;
 			if (p == s) {
 				/* We found the current sprite, remove it and move on. */
 				x = sprite_list.erase_after(prev);
 				continue;
+			}
 			auto p_prev = prev;
 			prev = x++;
 			if (s->xmax < p->xmin || s->ymax < p->ymin || s->zmax < p->zmin) continue;
 			if (s->xmin <= p->xmax && // overlap in X?
 					s->ymin <= p->ymax && // overlap in Y?
 					s->zmin <= p->zmax) { // overlap in Z?
 				if (s->xmin + s->xmax + s->ymin + s->ymax + s->zmin + s->zmax <=
 						p->xmin + p->xmax + p->ymin + p->ymax + p->zmin + p->zmax) {
 					continue;
+				}
+			}
 			/* Move ps2 in front of ps */
 			ParentSpriteToDraw *temp = ps2;
 			for (auto psd3 = psd2; psd3 > psd; psd3--) {
 				*psd3 = *(psd3 - 1);
 			preceding.push_back(p);
 			preceding_prev = p_prev;
+		}
 		if (preceding.empty()) {
 			/* No preceding sprites, add current one to the output */
 			*(out++) = s;
 			s->order = ORDER_RETURNED;
 			continue;
+		}
 		/* Optimization for the case when we only have 1 sprite to move. */
 		if (preceding.size() == 1) {
 			auto p = preceding[0];
 			/* We can only output the preceding sprite if there can't be any other sprites preceding it. */
 			if (p->xmax <= s->xmax && p->ymax <= s->ymax && p->zmax <= s->zmax) {
 				p->order = ORDER_RETURNED;
 				s->order = ORDER_RETURNED;
 				sprite_list.erase_after(preceding_prev);
 				*(out++) = p;
 				*(out++) = s;
 				continue;
+			}
 			*psd = temp;
+		}
 		/* Sort all preceding sprites by order and assign new orders in reverse (as original sorter did). */
 		std::sort(preceding.begin(), preceding.end(), [](const ParentSpriteToDraw *a, const ParentSpriteToDraw *b) {
 			return a->order >  b->order;
 		});
 		s->order = ORDER_COMPARED;
 		sprite_order.push(s);  // Still need to output so push it back for now
 		for (auto p: preceding) {
 			p->order = next_order++;
 			sprite_order.push(p);
+		}
+	}
+}
 static void ViewportDrawParentSprites(const ParentSpriteToSortVector *psd, const ChildScreenSpriteToDrawVector *csstdv)
+{
 	for (const ParentSpriteToDraw *ps : *psd) {

src/viewport_sprite_sorter.h

➞

Show inline comments

@@ @@ -36,7 +36,7 @@ struct ParentSpriteToDraw { @@
 	int32 top;                      ///< minimal screen Y coordinate of sprite (= y + sprite->y_offs), reference point for child sprites
 	int32 first_child;              ///< the first child to draw.
-	bool comparison_done;           ///< Used during sprite sorting: true if sprite has been compared with all other sprites
+	uint32 order;                   ///< Used during sprite sorting
 };
 typedef std::vector<ParentSpriteToDraw*> ParentSpriteToSortVector;

src/viewport_sprite_sorter_sse4.cpp

➞

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@@ @@ -13,6 +13,9 @@ @@
 #include "cpu.h"
 #include "smmintrin.h"
 #include "viewport_sprite_sorter.h"
 #include <forward_list>
 #include <map>
 #include <stack>
 #include "safeguards.h"
@@ @@ -23,74 +26,145 @@ @@
 #	define LOAD_128 _mm_loadu_si128
 #endif
 /** Sort parent sprites pointer array using SSE4.1 optimizations. */
 void ViewportSortParentSpritesSSE41(ParentSpriteToSortVector *psdv)
+{
 	if (psdv->size() < 2) return;
 	const __m128i mask_ptest = _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  0,  0,  0,  0);
 	auto const psdvend = psdv->end();
 	auto psd = psdv->begin();
 	while (psd != psdvend) {
 		ParentSpriteToDraw * const ps = *psd;
 	/* We rely on sprites being, for the most part, already ordered.
 	 * So we don't need to move many of them and can keep track of their
 	 * order efficiently by using stack. We always move sprites to the front
 	 * of the current position, i.e. to the top of the stack.
 	 * Also use special constants to indicate sorting state without
 	 * adding extra fields to ParentSpriteToDraw structure.
 	 */
 	const uint32 ORDER_COMPARED = UINT32_MAX; // Sprite was compared but we still need to compare the ones preceding it
 	const uint32 ORDER_RETURNED = UINT32_MAX - 1; // Mark sorted sprite in case there are other occurrences of it in the stack
 	std::stack<ParentSpriteToDraw *> sprite_order;
 	uint32 next_order = 0;
 	std::forward_list<std::pair<int64, ParentSpriteToDraw *>> sprite_list;  // We store sprites in a list sorted by xmin+ymin
 		if (ps->comparison_done) {
 			psd++;
 	/* Initialize sprite list and order. */
 	for (auto p = psdv->rbegin(); p != psdv->rend(); p++) {
 		sprite_list.push_front(std::make_pair((*p)->xmin + (*p)->ymin, *p));
 		sprite_order.push(*p);
 		(*p)->order = next_order++;
+	}
 	sprite_list.sort();
 	std::vector<ParentSpriteToDraw*> preceding;  // Temporarily stores sprites that precede current and their position in the list
 	auto preceding_prev = sprite_list.begin(); // Store iterator in case we need to delete a single preciding sprite
 	auto out = psdv->begin();  // Iterator to output sorted sprites
 	while (!sprite_order.empty()) {
 		auto s = sprite_order.top();
 		sprite_order.pop();
 		/* Sprite is already sorted, ignore it. */
 		if (s->order == ORDER_RETURNED) continue;
 		/* Sprite was already compared, just need to output it. */
 		if (s->order == ORDER_COMPARED) {
 			*(out++) = s;
 			s->order = ORDER_RETURNED;
 			continue;
+		}
 		ps->comparison_done = true;
 		for (auto psd2 = psd + 1; psd2 != psdvend; psd2++) {
 			ParentSpriteToDraw * const ps2 = *psd2;
 			if (ps2->comparison_done) continue;
 		preceding.clear();
 			/*
 			 * Decide which comparator to use, based on whether the bounding boxes overlap
+			 *
 			 * Original code:
 			 * if (ps->xmax >= ps2->xmin && ps->xmin <= ps2->xmax && // overlap in X?
 			 *     ps->ymax >= ps2->ymin && ps->ymin <= ps2->ymax && // overlap in Y?
 			 *     ps->zmax >= ps2->zmin && ps->zmin <= ps2->zmax) { // overlap in Z?
+			 *
 			 * Above conditions are equivalent to:
 			 * 1/    !( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin)   &&    (ps->xmin <= ps2->xmax) && (ps->ymin <= ps2->ymax) && (ps->zmin <= ps2->zmax) )
 			 * 2/    !( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin)   &&    (ps2->xmax >= ps->xmin) && (ps2->ymax >= ps->ymin) && (ps2->zmax >= ps->zmin) )
 			 * 3/  !( ( (ps->xmax >= ps2->xmin) && (ps->ymax >= ps2->ymin) && (ps->zmax >= ps2->zmin) ) &&  ( (ps2->xmax >= ps->xmin) && (ps2->ymax >= ps->ymin) && (ps2->zmax >= ps->zmin) ) )
 			 * 4/ !( !( (ps->xmax <  ps2->xmin) || (ps->ymax <  ps2->ymin) || (ps->zmax <  ps2->zmin) ) && !( (ps2->xmax <  ps->xmin) || (ps2->ymax <  ps->ymin) || (ps2->zmax <  ps->zmin) ) )
 			 * 5/ PTEST <---------------------------------- rslt1 ---------------------------------->         <------------------------------ rslt2 -------------------------------------->
 			 */
 			__m128i ps1_max = LOAD_128((__m128i*) &ps->xmax);
 			__m128i ps2_min = LOAD_128((__m128i*) &ps2->xmin);
 			__m128i rslt1 = _mm_cmplt_epi32(ps1_max, ps2_min);
 			if (!_mm_testz_si128(mask_ptest, rslt1))
 		/* We only need sprites with xmin <= s->xmax && ymin <= s->ymax && zmin <= s->zmax
 		 * So by iterating sprites with xmin + ymin <= s->xmax + s->ymax
 		 * we get all we need and some more that we filter out later.
 		 * We don't include zmin into the sum as there are usually more neighbors on x and y than z
 		 * so including it will actually increase the amount of false positives.
 		 * Also min coordinates can be > max so using max(xmin, xmax) + max(ymin, ymax)
 		 * to ensure that we iterate the current sprite as we need to remove it from the list.
 		 */
 		auto ssum = max(s->xmax, s->xmin) + max(s->ymax, s->ymin);
 		auto prev = sprite_list.before_begin();
 		auto x = sprite_list.begin();
 		while (x != sprite_list.end() && ((*x).first <= ssum)) {
 			auto p = (*x).second;
 			if (p == s) {
 				/* We found the current sprite, remove it and move on. */
 				x = sprite_list.erase_after(prev);
 				continue;
+			}
 			auto p_prev = prev;
 			prev = x++;
 			/* Check that p->xmin <= s->xmax && p->ymin <= s->ymax && p->zmin <= s->zmax */
 			__m128i s_max = LOAD_128((__m128i*) &s->xmax);
 			__m128i p_min = LOAD_128((__m128i*) &p->xmin);
 			__m128i r1 = _mm_cmplt_epi32(s_max, p_min);
 			if (!_mm_testz_si128(mask_ptest, r1))
 				continue;
 			__m128i ps1_min = LOAD_128((__m128i*) &ps->xmin);
 			__m128i ps2_max = LOAD_128((__m128i*) &ps2->xmax);
 			__m128i rslt2 = _mm_cmplt_epi32(ps2_max, ps1_min);
 			if (_mm_testz_si128(mask_ptest, rslt2)) {
 			/* Check if sprites overlap, i.e.
 			 * s->xmin <= p->xmax && s->ymin <= p->ymax && s->zmin <= p->zmax
 			 */
 			__m128i s_min = LOAD_128((__m128i*) &s->xmin);
 			__m128i p_max = LOAD_128((__m128i*) &p->xmax);
 			__m128i r2 = _mm_cmplt_epi32(p_max, s_min);
 			if (_mm_testz_si128(mask_ptest, r2)) {
 				/* Use X+Y+Z as the sorting order, so sprites closer to the bottom of
 				 * the screen and with higher Z elevation, are drawn in front.
 				 * Here X,Y,Z are the coordinates of the "center of mass" of the sprite,
 				 * i.e. X=(left+right)/2, etc.
 				 * However, since we only care about order, don't actually divide / 2
 				 */
 				if (ps->xmin + ps->xmax + ps->ymin + ps->ymax + ps->zmin + ps->zmax <=
 						ps2->xmin + ps2->xmax + ps2->ymin + ps2->ymax + ps2->zmin + ps2->zmax) {
 				if (s->xmin + s->xmax + s->ymin + s->ymax + s->zmin + s->zmax <=
 						p->xmin + p->xmax + p->ymin + p->ymax + p->zmin + p->zmax) {
 					continue;
+				}
+			}
 			/* Move ps2 in front of ps */
 			ParentSpriteToDraw * const temp = ps2;
 			for (auto psd3 = psd2; psd3 > psd; psd3--) {
 				*psd3 = *(psd3 - 1);
 			preceding.push_back(p);
 			preceding_prev = p_prev;
+		}
 		if (preceding.empty()) {
 			/* No preceding sprites, add current one to the output */
 			*(out++) = s;
 			s->order = ORDER_RETURNED;
 			continue;
+		}
 		/* Optimization for the case when we only have 1 sprite to move. */
 		if (preceding.size() == 1) {
 			auto p = preceding[0];
 			/* We can only output the preceding sprite if there can't be any other sprites preceding it. */
 			if (p->xmax <= s->xmax && p->ymax <= s->ymax && p->zmax <= s->zmax) {
 				p->order = ORDER_RETURNED;
 				s->order = ORDER_RETURNED;
 				sprite_list.erase_after(preceding_prev);
 				*(out++) = p;
 				*(out++) = s;
 				continue;
+			}
 			*psd = temp;
+		}
 		/* Sort all preceding sprites by order and assign new orders in reverse (as original sorter did). */
 		std::sort(preceding.begin(), preceding.end(), [](const ParentSpriteToDraw *a, const ParentSpriteToDraw *b) {
 			return a->order >  b->order;
 		});
 		s->order = ORDER_COMPARED;
 		sprite_order.push(s);  // Still need to output so push it back for now
 		for (auto p: preceding) {
 			p->order = next_order++;
 			sprite_order.push(p);
+		}
+	}
+}
 /**
  * Check whether the current CPU supports SSE 4.1.
  * @return True iff the CPU supports SSE 4.1.

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