Acs::PixelCacheRenderer Class Reference

#include <kis_acs_pixel_cache_renderer.h>

Static Public Member Functions
template<class Sampler >
static void	render (Sampler *sampler, const KisDisplayColorConverter *converter, const QRect &sampleRect, KisPaintDeviceSP &realPixelCache, QImage &pixelCache, QPoint &pixelCacheOffset, qreal devicePixelRatioF)

Detailed Description

Definition at line 18 of file kis_acs_pixel_cache_renderer.h.

Member Function Documentation

render()

template<class Sampler >

static void Acs::PixelCacheRenderer::render ( Sampler * sampler, const KisDisplayColorConverter * converter, const QRect & sampleRect, KisPaintDeviceSP & realPixelCache, QImage & pixelCache, QPoint & pixelCacheOffset, qreal devicePixelRatioF )

inlinestatic

Sampler class must provide one method:

• KoColor Sampler::colorAt(float x, float y);

How to handle High DPI:

• sampleRect - is in device independent pixels coordinates space (amount of space on the widget)
• devicePixelRatioF - the amount of UI scaling
• pixelCache and realPixelCache gets the size of sampleRect.size()*devicePixelRatioF and sets the device pixel ratio, and color samplers need to take it into account. That way you can paint on the cache the same way you'd paint on a low dpi display and then just use painter->drawImage() and it works.

Definition at line 36 of file kis_acs_pixel_cache_renderer.h.

            {
                const KoColorSpace *cacheColorSpace = converter->paintingColorSpace();
                const int pixelSize = cacheColorSpace->pixelSize();
 
                if (!realPixelCache || realPixelCache->colorSpace() != cacheColorSpace) {
                    realPixelCache = new KisPaintDevice(cacheColorSpace);
                }
 
                KoColor color;
 
                QRect sampleRectHighDPI = QRect(sampleRect.topLeft(), sampleRect.size()*devicePixelRatioF);
                KisSequentialIterator it(realPixelCache, sampleRectHighDPI);
 
                while (it.nextPixel()) {
                    color = sampler->colorAt(it.x()/devicePixelRatioF, it.y()/devicePixelRatioF);
                    memcpy(it.rawData(), color.data(), pixelSize);
                }
 
 
                // NOTE: toQImage() function of the converter copies exactBounds() only!
                pixelCache = converter->toQImage(realPixelCache);
                pixelCache.setDevicePixelRatio(devicePixelRatioF);
                pixelCacheOffset = realPixelCache->exactBounds().topLeft()/devicePixelRatioF - sampleRect.topLeft();
        }

References KisPaintDevice::colorSpace(), KoColor::data(), KisPaintDevice::exactBounds(), KisSequentialIteratorBase< IteratorPolicy, SourcePolicy, ProgressPolicy >::nextPixel(), KisDisplayColorConverter::paintingColorSpace(), KoColorSpace::pixelSize(), KisSequentialIteratorBase< IteratorPolicy, SourcePolicy, ProgressPolicy >::rawData(), KisDisplayColorConverter::toQImage(), KisSequentialIteratorBase< IteratorPolicy, SourcePolicy, ProgressPolicy >::x(), and KisSequentialIteratorBase< IteratorPolicy, SourcePolicy, ProgressPolicy >::y().

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The documentation for this class was generated from the following file:

• libs/global/kis_acs_pixel_cache_renderer.h