tahoma2d/toonz/sources/toonzqt/pickrgbutils.cpp

#include "tgl.h"

//Qt includes
#include <QPixmap>
#include <QImage>
#include <QGLWidget>
#include <QDesktopWidget>
#include <QApplication>

#include "toonzqt/pickrgbutils.h"

//*************************************************************************************
//    Local namespace
//*************************************************************************************

namespace
{

QRgb meanColor(const QImage &img, const QRect &rect)
{
	if (rect.width() == 1 && rect.height() == 1)
		return img.pixel(rect.left(), rect.top());

	int r, g, b, m;
	int x, y, x1 = rect.right(), y1 = rect.bottom(), count = rect.width() * rect.height();

	r = g = b = m = 0;
	for (y = rect.top(); y <= y1; ++y)
		for (x = rect.left(); x <= x1; ++x) {
			QRgb color = img.pixel(x, y);

			r += (color & 0xff);
			g += ((color >> 8) & 0xff);
			b += ((color >> 16) & 0xff);
			m += ((color >> 24) & 0xff);
		}

	r = r / count;
	g = g / count;
	b = b / count;
	m = m / count;

	return r | (g << 8) | (b << 16) | (m << 24);
}
}

//==============================================================================

QRgb pickRGB(QWidget *widget, const QRect &rect)
{
	QImage img(QPixmap::grabWidget(widget, rect.x(), rect.y(), rect.width(), rect.height()).toImage());
	return meanColor(img, img.rect());
}

//------------------------------------------------------------------------------

QRgb pickScreenRGB(const QRect &rect)
{
	QWidget *widget = QApplication::desktop();

#ifdef MACOSX

	//   #Bugzilla 6514, possibly related to #QTBUG 23516

	// Screen grabbing on a secondary screen seems to be broken on MAC
	// (see what happens using PixelTool), when no piece of the *primary*
	// screen is involved in the grab. As it seems to be very Qt-based,
	// the workaround is to trivially grab the smallest rect including the
	// requested one and a part of the primary screen.

	const QRect &screen0Geom = QApplication::desktop()->screenGeometry(0);

	int left = std::min(rect.left(), screen0Geom.right());
	int top = std::min(rect.top(), screen0Geom.bottom());
	int right = std::max(rect.right(), screen0Geom.left());
	int bottom = std::max(rect.bottom(), screen0Geom.right());

	QRect theRect(QPoint(left, top), QPoint(right, bottom));

#else

	const QRect &theRect = rect;

#endif

	QImage img(QPixmap::grabWindow(widget->winId(), theRect.x(), theRect.y(), theRect.width(), theRect.height()).toImage());
	return meanColor(img, QRect(rect.left() - theRect.left(), rect.top() - theRect.top(), rect.width(), rect.height()));
}

//------------------------------------------------------------------------------

QRgb pickRGB(QGLWidget *widget, const QRect &rect)
{
	widget->makeCurrent();

	glReadBuffer(GL_FRONT);

	QImage img(rect.size(), QImage::Format_ARGB32);
	glReadPixels(rect.x(), widget->height() - rect.y(), rect.width(), rect.height(),
				 GL_BGRA_EXT, GL_UNSIGNED_BYTE, img.bits());

	widget->doneCurrent();

	return meanColor(img, img.rect());
}