[poppler] [PATCH v2 2/5] SplashXPathScanner: Reset span state explicitly when advancing line

[Stefan Brüns]

Avoid checking for a line change in each span. The required state reset
can be done from the call site.
---
 splash/Splash.cc             |  9 +++++++++
 splash/SplashXPathScanner.cc | 19 ++++++++++---------
 splash/SplashXPathScanner.h  | 12 ++++++------
 3 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/splash/Splash.cc b/splash/Splash.cc
index d749ab03..1eb907d8 100644
--- a/splash/Splash.cc
+++ b/splash/Splash.cc
@@ -2612,6 +2612,9 @@ SplashError Splash::fillWithPattern(SplashPath *path, GBool eo,
       }
     } else {
       for (y = yMinI; y <= yMaxI; ++y) {
+	if (!scanner->setRow(y)) {
+          continue;
+        }
 	while (scanner->getNextSpan(y, &x0, &x1)) {
 	  if (clipRes == splashClipAllInside) {
 	    drawSpan(&pipe, x0, x1, y, gTrue);
@@ -2736,6 +2739,9 @@ SplashError Splash::xorFill(SplashPath *path, GBool eo) {
 
     // draw the spans
     for (y = yMinI; y <= yMaxI; ++y) {
+      if (!scanner->setRow(y)) {
+        continue;
+      }
       while (scanner->getNextSpan(y, &x0, &x1)) {
 	if (clipRes == splashClipAllInside) {
 	  drawSpan(&pipe, x0, x1, y, gTrue);
@@ -6492,6 +6498,9 @@ SplashError Splash::shadedFill(SplashPath *path, GBool hasBBox,
     } else {
       SplashClipResult clipRes2;
       for (y = yMinI; y <= yMaxI; ++y) {
+        if (!scanner->setRow(y)) {
+          continue;
+        }
         while (scanner->getNextSpan(y, &x0, &x1)) {
           if (clipRes == splashClipAllInside) {
             drawSpan(&pipe, x0, x1, y, gTrue);
diff --git a/splash/SplashXPathScanner.cc b/splash/SplashXPathScanner.cc
index 1e48e90b..b36f5322 100644
--- a/splash/SplashXPathScanner.cc
+++ b/splash/SplashXPathScanner.cc
@@ -122,7 +122,6 @@ SplashXPathScanner::SplashXPathScanner(SplashXPath *xPathA, GBool eoA,
   allInter = nullptr;
   inter = nullptr;
   computeIntersections();
-  interY = yMin - 1;
 }
 
 SplashXPathScanner::~SplashXPathScanner() {
@@ -216,14 +215,6 @@ GBool SplashXPathScanner::testSpan(int x0, int x1, int y) {
 GBool SplashXPathScanner::getNextSpan(int y, int *x0, int *x1) {
   int interEnd, xx0, xx1;
 
-  if (y < yMin || y > yMax) {
-    return gFalse;
-  }
-  if (interY != y) {
-    interY = y;
-    interIdx = inter[y - yMin];
-    interCount = 0;
-  }
   interEnd = inter[y - yMin + 1];
   if (interIdx >= interEnd) {
     return gFalse;
@@ -246,6 +237,16 @@ GBool SplashXPathScanner::getNextSpan(int y, int *x0, int *x1) {
   return gTrue;
 }
 
+GBool SplashXPathScanner::setRow(int y) {
+  if (y < yMin || y > yMax) {
+    return gFalse;
+  }
+
+  interCount = 0;
+  interIdx = inter[y - yMin];
+  return gTrue;
+}
+
 void SplashXPathScanner::computeIntersections() {
   SplashXPathSeg *seg;
   SplashCoord segXMin, segXMax, segYMin, segYMax, xx0, xx1;
diff --git a/splash/SplashXPathScanner.h b/splash/SplashXPathScanner.h
index b6c358d9..99f2c28f 100644
--- a/splash/SplashXPathScanner.h
+++ b/splash/SplashXPathScanner.h
@@ -69,13 +69,14 @@ public:
   // path.
   GBool testSpan(int x0, int x1, int y);
 
-  // Returns the next span inside the path at <y>.  If <y> is
-  // different than the previous call to getNextSpan, this returns the
-  // first span at <y>; otherwise it returns the next span (relative
-  // to the previous call to getNextSpan).  Returns false if there are
-  // no more spans at <y>.
+  // Returns the next span inside the path at <y>.
+  // Returns false if there are no more spans at <y>.
   GBool getNextSpan(int y, int *x0, int *x1);
 
+  // Sets the current span to the first span at <y>.
+  // Returns false if the row is outside the path.
+  GBool setRow(int y);
+
   // Renders one anti-aliased line into <aaBuf>.  Returns the min and
   // max x coordinates with non-zero pixels in <x0> and <x1>.
   void renderAALine(SplashBitmap *aaBuf, int *x0, int *x1, int y,
@@ -102,7 +103,6 @@ private:
   int allInterLen;		// number of intersections in <allInter>
   int allInterSize;		// size of the <allInter> array
   int *inter;			// indexes into <allInter> for each y value
-  int interY;			// current y value - used by getNextSpan
   int interIdx;			// current index into <inter> - used by
 				//   getNextSpan 
   int interCount;		// current EO/NZWN counter - used by
-- 
2.16.3