Faster draw for multiband color in case there is no transparency, strech, inversion

mhugent · mhugent · commit 3b36620c49df · 2012-01-28T13:16:05.000+01:00
diff --git a/src/core/raster/qgsmultibandcolorrenderer.cpp b/src/core/raster/qgsmultibandcolorrenderer.cpp
@@ -18,6 +18,7 @@
 #include "qgsmultibandcolorrenderer.h"
 #include "qgscontrastenhancement.h"
 #include "qgsrastertransparency.h"
+#include "qgsrasterviewport.h"
 #include <QImage>
 #include <QSet>
 
@@ -41,6 +42,13 @@ void QgsMultiBandColorRenderer::draw( QPainter* p, QgsRasterViewPort* viewPort,
     return;
   }
 
+  //In some (common) cases, we can simplify the drawing loop considerably and save render time
+  bool fastDraw = (
+                    !usesTransparency( viewPort->mSrcCRS, viewPort->mDestCRS )
+                    && mRedBand > 0 && mGreenBand > 0 && mBlueBand > 0
+                    && mAlphaBand < 1 && !mRedContrastEnhancement && !mGreenContrastEnhancement && !mBlueContrastEnhancement
+                    && !mInvertColor );
+
   QgsRasterDataProvider::DataType redType;
   if ( mRedBand > 0 )
   {
@@ -155,15 +163,26 @@ void QgsMultiBandColorRenderer::draw( QPainter* p, QgsRasterViewPort* viewPort,
       imageScanLine = ( QRgb* )( img.scanLine( i ) );
       for ( int j = 0; j < nRasterCols; ++j )
       {
-        if ( mRedBand )
+
+        if ( fastDraw ) //fast rendering if no transparency, stretching, color inversion, etc.
+        {
+          redVal = readValue( redData, redType, currentRasterPos );
+          greenVal = readValue( greenData, greenType, currentRasterPos );
+          blueVal = readValue( blueData, blueType, currentRasterPos );
+          imageScanLine[j] = qRgba( redVal, greenVal, blueVal, 255 );
+          ++currentRasterPos;
+          continue;
+        }
+
+        if ( mRedBand > 0 )
         {
           redVal = readValue( redData, redType, currentRasterPos );
         }
-        if ( mGreenBand )
+        if ( mGreenBand > 0 )
         {
           greenVal = readValue( greenData, greenType, currentRasterPos );
         }
-        if ( mBlueBand )
+        if ( mBlueBand > 0 )
         {
           blueVal = readValue( blueData, blueType, currentRasterPos );
         }
diff --git a/src/core/raster/qgsrasterlayer.cpp b/src/core/raster/qgsrasterlayer.cpp
@@ -693,21 +693,30 @@ void QgsRasterLayer::setRendererForDrawingStyle( const DrawingStyle &  theDrawin
       if ( mRedBandName != TRSTRING_NOT_SET )
       {
         red = bandNumber( mRedBandName );
-        redEnhancement = contrastEnhancement( red );
+        if ( contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement )
+        {
+          redEnhancement = contrastEnhancement( red );
+        }
       }
       int green = -1;
       QgsContrastEnhancement* greenEnhancement = 0;
       if ( mGreenBandName != TRSTRING_NOT_SET )
       {
         green = bandNumber( mGreenBandName );
-        greenEnhancement = contrastEnhancement( green );
+        if ( contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement )
+        {
+          greenEnhancement = contrastEnhancement( green );
+        }
       }
       int blue = -1;
       QgsContrastEnhancement* blueEnhancement = 0;
       if ( mBlueBandName != TRSTRING_NOT_SET )
       {
         blue = bandNumber( mBlueBandName );
-        blueEnhancement = contrastEnhancement( blue );
+        if ( contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement )
+        {
+          blueEnhancement = contrastEnhancement( blue );
+        }
       }
       renderer = new QgsMultiBandColorRenderer( mDataProvider, red, green, blue,
           redEnhancement, greenEnhancement, blueEnhancement );
diff --git a/src/core/raster/qgsrastertransparency.cpp b/src/core/raster/qgsrastertransparency.cpp
@@ -177,6 +177,6 @@ bool QgsRasterTransparency::isEmpty( double nodataValue ) const
              ( mTransparentSingleValuePixelList.size() == 1 && doubleNear( mTransparentSingleValuePixelList.at( 0 ).pixelValue, nodataValue ) ) )
            &&
            ( mTransparentThreeValuePixelList.isEmpty() ||
-             ( mTransparentThreeValuePixelList.size() == 1 && doubleNear( mTransparentThreeValuePixelList.at( 0 ).red, nodataValue ) &&
+             ( mTransparentThreeValuePixelList.size() < 4 && doubleNear( mTransparentThreeValuePixelList.at( 0 ).red, nodataValue ) &&
                doubleNear( mTransparentThreeValuePixelList.at( 0 ).green, nodataValue ) && doubleNear( mTransparentThreeValuePixelList.at( 0 ).blue, nodataValue ) ) ) );
 }

Original file line number	Diff line number	Diff line change
`@@ -18,6 +18,7 @@`
`18`	`18`	`#include "qgsmultibandcolorrenderer.h"`
`19`	`19`	`#include "qgscontrastenhancement.h"`
`20`	`20`	`#include "qgsrastertransparency.h"`
	`21`	`+#include "qgsrasterviewport.h"`
`21`	`22`	`#include <QImage>`
`22`	`23`	`#include <QSet>`
`23`	`24`
`@@ -41,6 +42,13 @@ void QgsMultiBandColorRenderer::draw( QPainter* p, QgsRasterViewPort* viewPort,`
`41`	`42`	`return;`
`42`	`43`	`}`
`43`	`44`
	`45`	`+ //In some (common) cases, we can simplify the drawing loop considerably and save render time`
	`46`	`+ bool fastDraw = (`
	`47`	`+ !usesTransparency( viewPort->mSrcCRS, viewPort->mDestCRS )`
	`48`	`+ && mRedBand > 0 && mGreenBand > 0 && mBlueBand > 0`
	`49`	`+ && mAlphaBand < 1 && !mRedContrastEnhancement && !mGreenContrastEnhancement && !mBlueContrastEnhancement`
	`50`	`+ && !mInvertColor );`
	`51`	`+`
`44`	`52`	`QgsRasterDataProvider::DataType redType;`
`45`	`53`	`if ( mRedBand > 0 )`
`46`	`54`	`{`
`@@ -155,15 +163,26 @@ void QgsMultiBandColorRenderer::draw( QPainter* p, QgsRasterViewPort* viewPort,`
`155`	`163`	`imageScanLine = ( QRgb* )( img.scanLine( i ) );`
`156`	`164`	`for ( int j = 0; j < nRasterCols; ++j )`
`157`	`165`	`{`
`158`		`- if ( mRedBand )`
	`166`	`+`
	`167`	`+ if ( fastDraw ) //fast rendering if no transparency, stretching, color inversion, etc.`
	`168`	`+ {`
	`169`	`+ redVal = readValue( redData, redType, currentRasterPos );`
	`170`	`+ greenVal = readValue( greenData, greenType, currentRasterPos );`
	`171`	`+ blueVal = readValue( blueData, blueType, currentRasterPos );`
	`172`	`+ imageScanLine[j] = qRgba( redVal, greenVal, blueVal, 255 );`
	`173`	`+ ++currentRasterPos;`
	`174`	`+ continue;`
	`175`	`+ }`
	`176`	`+`
	`177`	`+ if ( mRedBand > 0 )`
`159`	`178`	`{`
`160`	`179`	`redVal = readValue( redData, redType, currentRasterPos );`
`161`	`180`	`}`
`162`		`- if ( mGreenBand )`
	`181`	`+ if ( mGreenBand > 0 )`
`163`	`182`	`{`
`164`	`183`	`greenVal = readValue( greenData, greenType, currentRasterPos );`
`165`	`184`	`}`
`166`		`- if ( mBlueBand )`
	`185`	`+ if ( mBlueBand > 0 )`
`167`	`186`	`{`
`168`	`187`	`blueVal = readValue( blueData, blueType, currentRasterPos );`
`169`	`188`	`}`
Original file line number	Diff line number	Diff line change
`@@ -693,21 +693,30 @@ void QgsRasterLayer::setRendererForDrawingStyle( const DrawingStyle & theDrawin`
`693`	`693`	`if ( mRedBandName != TRSTRING_NOT_SET )`
`694`	`694`	`{`
`695`	`695`	`red = bandNumber( mRedBandName );`
`696`		`- redEnhancement = contrastEnhancement( red );`
	`696`	`+ if ( contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement )`
	`697`	`+ {`
	`698`	`+ redEnhancement = contrastEnhancement( red );`
	`699`	`+ }`
`697`	`700`	`}`
`698`	`701`	`int green = -1;`
`699`	`702`	`QgsContrastEnhancement* greenEnhancement = 0;`
`700`	`703`	`if ( mGreenBandName != TRSTRING_NOT_SET )`
`701`	`704`	`{`
`702`	`705`	`green = bandNumber( mGreenBandName );`
`703`		`- greenEnhancement = contrastEnhancement( green );`
	`706`	`+ if ( contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement )`
	`707`	`+ {`
	`708`	`+ greenEnhancement = contrastEnhancement( green );`
	`709`	`+ }`
`704`	`710`	`}`
`705`	`711`	`int blue = -1;`
`706`	`712`	`QgsContrastEnhancement* blueEnhancement = 0;`
`707`	`713`	`if ( mBlueBandName != TRSTRING_NOT_SET )`
`708`	`714`	`{`
`709`	`715`	`blue = bandNumber( mBlueBandName );`
`710`		`- blueEnhancement = contrastEnhancement( blue );`
	`716`	`+ if ( contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement )`
	`717`	`+ {`
	`718`	`+ blueEnhancement = contrastEnhancement( blue );`
	`719`	`+ }`
`711`	`720`	`}`
`712`	`721`	`renderer = new QgsMultiBandColorRenderer( mDataProvider, red, green, blue,`
`713`	`722`	`redEnhancement, greenEnhancement, blueEnhancement );`
Original file line number	Diff line number	Diff line change
`@@ -177,6 +177,6 @@ bool QgsRasterTransparency::isEmpty( double nodataValue ) const`
`177`	`177`	`( mTransparentSingleValuePixelList.size() == 1 && doubleNear( mTransparentSingleValuePixelList.at( 0 ).pixelValue, nodataValue ) ) )`
`178`	`178`	`&&`
`179`	`179`	`( mTransparentThreeValuePixelList.isEmpty() \|\|`
`180`		`- ( mTransparentThreeValuePixelList.size() == 1 && doubleNear( mTransparentThreeValuePixelList.at( 0 ).red, nodataValue ) &&`
	`180`	`+ ( mTransparentThreeValuePixelList.size() < 4 && doubleNear( mTransparentThreeValuePixelList.at( 0 ).red, nodataValue ) &&`
`181`	`181`	`doubleNear( mTransparentThreeValuePixelList.at( 0 ).green, nodataValue ) && doubleNear( mTransparentThreeValuePixelList.at( 0 ).blue, nodataValue ) ) ) );`
`182`	`182`	`}`