When grabbing the white balance, grab a single pixel instead of the entire framebuffer.

diff --git a/glwidget.cpp b/glwidget.cpp
index 574bf61a6b3e116fa219a5df1245fddb780f37e2..bf537de2dbdb0806d2c41fec0b8ebf3fcd74d8e7 100644 (file)
--- a/glwidget.cpp
+++ b/glwidget.cpp
@@ -152,11 +152,12 @@ void GLWidget::paintGL()
        }
 
        if (should_grab) {
-               QRgb reference_color = grabFrameBuffer().pixel(grab_x, grab_y);
+               GLfloat reference_color[4];
+               glReadPixels(grab_x, current_height - grab_y - 1, 1, 1, GL_BGRA, GL_FLOAT, reference_color);
 
-               double r = srgb_to_linear(qRed(reference_color) / 255.0);
-               double g = srgb_to_linear(qGreen(reference_color) / 255.0);
-               double b = srgb_to_linear(qBlue(reference_color) / 255.0);
+               double r = srgb_to_linear(reference_color[2]);
+               double g = srgb_to_linear(reference_color[1]);
+               double b = srgb_to_linear(reference_color[0]);
                global_mixer->set_wb(grab_output, r, g, b);
                should_grab = false;
        }