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From Eric Wing, fix for compute of the bounding box when handling outline/backdrop text.

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This commit is contained in:
Robert Osfield
2006-08-22 10:23:58 +00:00
parent 71c79506e9
commit 98cdf9b3c7
2 changed files with 97 additions and 34 deletions
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127
src/osgText/Text.cpp
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@@ -722,12 +722,73 @@ void Text::computeGlyphRepresentation()
}
computePositions();
computeBackdropBoundingBox();
computeColorGradients();
}
// Returns false if there are no glyphs and the width/height values are invalid.
// Also sets avg_width and avg_height to 0.0f if the value is invalid.
// This method is used several times in a loop for the same object which will produce the same values.
// Further optimization may try saving these values instead of recomputing them.
bool Text::computeAverageGlypthWidthAndHeight(float& avg_width, float& avg_height) const
{
float width = 0.0f;
float height = 0.0f;
float running_width = 0.0f;
float running_height = 0.0f;
avg_width = 0.0f;
avg_height = 0.0f;
int counter = 0;
unsigned int i;
bool is_valid_size = true;
// This section is going to try to compute the average width and height
// for a character among the text. The reason I shift by an
// average amount per-character instead of shifting each character
// by its per-instance amount is because it may look strange to see
// the individual backdrop text letters not space themselves the same
// way the foreground text does. Using one value gives uniformity.
// Note: This loop is repeated for each context. I think it may produce
// the same values regardless of context. This code be optimized by moving
// this loop outside the loop.
for(TextureGlyphQuadMap::const_iterator const_titr=_textureGlyphQuadMap.begin();
const_titr!=_textureGlyphQuadMap.end();
++const_titr)
{
const GlyphQuads& glyphquad = const_titr->second;
const GlyphQuads::Coords2& coords2 = glyphquad._coords;
for(i = 0; i < coords2.size(); i+=4)
{
width = coords2[i+2].x() - coords2[i].x();
height = coords2[i].y() - coords2[i+1].y();
running_width += width;
running_height += height;
counter++;
}
}
if(0 == counter)
{
is_valid_size = false;
}
else
{
avg_width = running_width/counter;
avg_height = running_height/counter;
}
return is_valid_size;
}
void Text::computePositions()
{
unsigned int size = osg::maximum(osg::DisplaySettings::instance()->getMaxNumberOfGraphicsContexts(),_autoTransformCache.size());
// FIXME: OPTIMIZE: This would be one of the ideal locations to
// call computeAverageGlypthWidthAndHeight(). It is out of the contextID loop
// so the value would be computed fewer times. But the code will need changes
// to get the value down to the locations it is needed. (Either pass through parameters
// or member variables, but we would need a system to know if the values are stale.)
for(unsigned int i=0;i<size;++i)
{
computePositions(i);
@@ -896,42 +957,19 @@ void Text::computeBackdropPositions(unsigned int contextID) const
return;
}
float width = 0.0f;
float height = 0.0f;
float running_width = 0.0f;
float running_height = 0.0f;
float avg_width = 0.0f;
float avg_height = 0.0f;
int counter = 0;
unsigned int i;
bool is_valid_size;
AutoTransformCache& atc = _autoTransformCache[contextID];
osg::Matrix& matrix = atc._matrix;
// This section is going to try to compute the average width and height
// for a character among the text. The reason I shift by an
// average amount per-character instead of shifting each character
// by its per-instance amount is because it may look strange to see
// the individual backdrop text letters not space themselves the same
// way the foreground text does. Using one value gives uniformity.
for(TextureGlyphQuadMap::const_iterator const_titr=_textureGlyphQuadMap.begin();
const_titr!=_textureGlyphQuadMap.end();
++const_titr)
{
const GlyphQuads& glyphquad = const_titr->second;
const GlyphQuads::Coords2& coords2 = glyphquad._coords;
for(i = 0; i < coords2.size(); i+=4)
{
width = coords2[i+2].x() - coords2[i].x();
height = coords2[i].y() - coords2[i+1].y();
running_width += width;
running_height += height;
counter++;
}
}
avg_width = running_width/counter;
avg_height = running_height/counter;
// FIXME: OPTIMIZE: This function produces the same value regardless of contextID.
// Since we tend to loop over contextID, we should cache this value some how
// instead of recomputing it each time.
is_valid_size = computeAverageGlypthWidthAndHeight(avg_width, avg_height);
// now apply matrix to the glyphs.
for(TextureGlyphQuadMap::iterator titr=_textureGlyphQuadMap.begin();
titr!=_textureGlyphQuadMap.end();
@@ -1036,11 +1074,33 @@ void Text::computeBackdropPositions(unsigned int contextID) const
}
}
}
}
#if 0
// note, commenting out right now as its causing bounding box problems
// which haven't yet been located and fixed. Robert Osfield, August 2006.
// This method adjusts the bounding box to account for the expanded area caused by the backdrop.
// This assumes that the bounding box has already been computed for the text without the backdrop.
void Text::computeBackdropBoundingBox() const
{
if(_backdropType == NONE)
{
return;
}
float avg_width = 0.0f;
float avg_height = 0.0f;
bool is_valid_size;
// FIXME: OPTIMIZE: It is possible that this value has already been computed before
// from previous calls to this function. This might be worth optimizing.
is_valid_size = computeAverageGlypthWidthAndHeight(avg_width, avg_height);
// Finally, we have one more issue to deal with.
// Now that the text takes more space, we need
// to adjust the size of the bounding box.
if((!_textBB.valid() || !is_valid_size))
{
return;
}
// Finally, we have one more issue to deal with.
// Now that the text takes more space, we need
// to adjust the size of the bounding box.
@@ -1158,7 +1218,6 @@ void Text::computeBackdropPositions(unsigned int contextID) const
break;
}
}
#endif
}
void Text::computeColorGradients() const