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Fix for ticket #475. The fix has introduced an intermittent off-by-on…
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…e-pixel

display problem, but that's better than the original problem! 

The solution was to remove what looked like some testing code that somehow got
committed a while ago.


git-svn-id: http://svn.osgeo.org/qgis/trunk@6358 c8812cc2-4d05-0410-92ff-de0c093fc19c
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g_j_m committed Dec 31, 2006
1 parent 5604200 commit de66849
Showing 1 changed file with 0 additions and 85 deletions.
85 changes: 0 additions & 85 deletions src/raster/qgsrasterlayer.cpp
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Expand Up @@ -1132,14 +1132,6 @@ __FUNCTION__, __LINE__);
myRasterViewPort->clippedHeightInt =
abs(static_cast < int >(myRasterViewPort->clippedYMaxDouble - myRasterViewPort->clippedYMinDouble)) + 2;

/*
// Add one to the raster dimensions to guard against the integer truncation
// effects of static_cast<int>
// TODO: Can we get rid of this now that we are rounding at the point of the static_cast?
myRasterViewPort->clippedWidthInt++;
myRasterViewPort->clippedHeightInt++;
*/

// but make sure the intended SE corner extent doesn't exceed the SE corner
// of the source raster, otherwise GDAL's RasterIO gives an error and returns nothing.
// The SE corner = NW origin + dimensions of the image itself.
Expand All @@ -1156,92 +1148,15 @@ __FUNCTION__, __LINE__);
rasterYDimInt - myRasterViewPort->rectYOffsetInt;
}

/*
if (myRasterViewPort->clippedWidthInt > rasterXDimInt)
{
myRasterViewPort->clippedWidthInt = rasterXDimInt;
}
if (myRasterViewPort->clippedHeightInt > rasterYDimInt)
{
myRasterViewPort->clippedHeightInt = rasterYDimInt;
}
*/

// get dimensions of clipped raster image in device coordinate space (this is the size of the viewport)
myRasterViewPort->topLeftPoint = theQgsMapToPixel->transform(myRasterExtent.xMin(), myRasterExtent.yMax());
myRasterViewPort->bottomRightPoint = theQgsMapToPixel->transform(myRasterExtent.xMax(), myRasterExtent.yMin());

// Try a different method - round up to the nearest whole source pixel.
myRasterViewPort->drawableAreaXDimInt =
abs(static_cast<int> (myRasterViewPort->clippedWidthInt / theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[1]));
myRasterViewPort->drawableAreaYDimInt =
abs(static_cast<int> (myRasterViewPort->clippedHeightInt / theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[5]));

/*
myRasterViewPort->drawableAreaXDimInt =
static_cast<int> ((myRasterViewPort->clippedXMaxDouble - myRasterViewPort->clippedXMinDouble) /
theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[1]);
myRasterViewPort->drawableAreaYDimInt =
static_cast<int> ((myRasterViewPort->clippedYMaxDouble - myRasterViewPort->clippedYMinDouble) /
theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[5]);
*/

/*
// Since GDAL's RasterIO can't handle floating point, we have to round to
// the nearest pixel. Add 0.5 to get rounding instead of truncation
// out of static_cast<int>.
myRasterViewPort->drawableAreaXDimInt =
static_cast<int>(myRasterViewPort->bottomRightPoint.x() + 0.5) -
static_cast<int>(myRasterViewPort->topLeftPoint .x() + 0.5);
*/

// get dimensions of clipped raster image in raster pixel space/ RasterIO will do the scaling for us.
// So for example, if the user is zoomed in a long way, there may only be e.g. 5x5 pixels retrieved from
// the raw raster data, but rasterio will seamlessly scale the up to whatever the screen coordinats are
// e.g. a 600x800 display window (see next section below)
myRasterViewPort->clippedXMinDouble = (myRasterExtent.xMin() - adfGeoTransform[0]) / adfGeoTransform[1];
myRasterViewPort->clippedXMaxDouble = (myRasterExtent.xMax() - adfGeoTransform[0]) / adfGeoTransform[1];
myRasterViewPort->clippedYMinDouble = (myRasterExtent.yMin() - adfGeoTransform[3]) / adfGeoTransform[5];
myRasterViewPort->clippedYMaxDouble = (myRasterExtent.yMax() - adfGeoTransform[3]) / adfGeoTransform[5];
myRasterViewPort->clippedWidthInt =
abs(static_cast < int >(myRasterViewPort->clippedXMaxDouble - myRasterViewPort->clippedXMinDouble));
myRasterViewPort->clippedHeightInt =
abs(static_cast < int >(myRasterViewPort->clippedYMaxDouble - myRasterViewPort->clippedYMinDouble));

// Add one to the raster dimensions to guard against the integer truncation
// effects of static_cast<int>
// TODO: Can we get rid of this now that we are rounding at the point of the static_cast?
myRasterViewPort->clippedWidthInt++;
myRasterViewPort->clippedHeightInt++;

// make sure we don't exceed size of raster, otherwise GDAL RasterIO doesn't like it
if (myRasterViewPort->clippedWidthInt > rasterXDimInt)
{
myRasterViewPort->clippedWidthInt = rasterXDimInt;
}
if (myRasterViewPort->clippedHeightInt > rasterYDimInt)
{
myRasterViewPort->clippedHeightInt = rasterYDimInt;
}

// get dimensions of clipped raster image in device coordinate space (this is the size of the viewport)
myRasterViewPort->topLeftPoint = theQgsMapToPixel->transform(myRasterExtent.xMin(), myRasterExtent.yMax());
myRasterViewPort->bottomRightPoint = theQgsMapToPixel->transform(myRasterExtent.xMax(), myRasterExtent.yMin());

// Since GDAL's RasterIO can't handle floating point, we have to round to
// the nearest pixel. Add 0.5 to get rounding instead of truncation
// out of static_cast<int>.
myRasterViewPort->drawableAreaXDimInt =
static_cast<int>(myRasterViewPort->bottomRightPoint.x() + 0.5) -
static_cast<int>(myRasterViewPort->topLeftPoint .x() + 0.5);

myRasterViewPort->drawableAreaYDimInt =
static_cast<int>(myRasterViewPort->bottomRightPoint.y() + 0.5) -
static_cast<int>(myRasterViewPort->topLeftPoint .y() + 0.5);

#ifdef QGISDEBUG
QgsLogger::debug("QgsRasterLayer::draw: mapUnitsPerPixel", theQgsMapToPixel->mapUnitsPerPixel(), 1, __FILE__,\
__FUNCTION__, __LINE__);
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