+ if (x <= 0) {
+ return 0;
+ }
+ if (x > 255) {
+ return 255;
+ }
+ return x;
+}
+
+void ImageViewer::slotUpdate()
+{
+ m_convertedImage =
+ m_convertedImage.mirrored(false, flipCheckBox->isChecked());
+
+ double lowerValue = lowerSpinBox->value();
+ double upperValue = upperSpinBox->value();
+
+ bool opaque = opaqueCheckBox->isChecked();
+ bool alpha = alphaCheckBox->isChecked();
+
+ if (lowerValue != 0.0 || upperValue != 1.0 || opaque || alpha) {
+ /*
+ * Rescale the image.
+ *
+ * XXX: This would be much more useful if done with the full precision
+ * of the original image
+ */
+
+ int offset = - lowerValue * 255;
+ int scale = 256 / (upperValue - lowerValue);
+
+ m_convertedImage =
+ m_convertedImage.convertToFormat(QImage::Format_ARGB32);
+
+ if (0) {
+ qDebug()
+ << "offset = " << offset << "\n"
+ << "scale = " << scale << "\n";
+ }
+
+ int width = m_convertedImage.width();
+ int height = m_convertedImage.height();
+
+ int aMask = opaque ? 0xff : 0;
+
+ for (int y = 0; y < height; ++y) {
+ QRgb *scanline = (QRgb *)m_convertedImage.scanLine(y);
+ for (int x = 0; x < width; ++x) {
+ QRgb pixel = scanline[x];
+ int r = qRed(pixel);
+ int g = qGreen(pixel);
+ int b = qBlue(pixel);
+ int a = qAlpha(pixel);
+ if (alpha) {
+ a = clamp(((a + offset) * scale) >> 8);
+ scanline[x] = qRgba(a, a, a, 0xff);
+ } else {
+ r = clamp(((r + offset) * scale) >> 8);
+ g = clamp(((g + offset) * scale) >> 8);
+ b = clamp(((b + offset) * scale) >> 8);
+ a |= aMask;
+ scanline[x] = qRgba(r, g, b, a);
+ }
+ }
+ }
+ }
+
+ m_pixelWidget->setSurface(m_convertedImage);
+