Function LargeWorldCallback

src/screenshot.cpp:88–126

* generate a large piece of the world * @param vp Viewport area to draw * @param buf Videobuffer with same bitdepth as current blitter * @param y First line to render * @param pitch Pitch of the videobuffer * @param n Number of lines to render */

 * @param n Number of lines to render
 */
static void LargeWorldCallback(Viewport &vp, void *buf, uint y, uint pitch, uint n)
{
	DrawPixelInfo dpi{
		.dst_ptr = buf,
		.left = 0,
		.top = static_cast<int>(y),
		.width = vp.width,
		.height = static_cast<int>(n),
		.pitch = static_cast<int>(pitch),
		.zoom = ZoomLevel::WorldScreenshot
	};

	/* We are no longer rendering to the screen */
	AutoRestoreBackup screen_backup(_screen, {
		.dst_ptr = buf,
		.left = 0,
		.top = 0,
		.width = static_cast<int>(pitch),
		.height = static_cast<int>(n),
		.pitch = static_cast<int>(pitch),
		.zoom = ZoomLevel::Min
	});
	AutoRestoreBackup disable_anim_backup(_screen_disable_anim, true);
	AutoRestoreBackup dpi_backup(_cur_dpi, &dpi);

	/* Render viewport in blocks of 1600 pixels width */
	int left = 0;
	while (vp.width - left != 0) {
		int wx = std::min(vp.width - left, 1600);
		left += wx;

		ViewportDoDraw(vp,
			ScaleByZoom(left - wx - vp.left, vp.zoom) + vp.virtual_left,
			ScaleByZoom(y - vp.top, vp.zoom) + vp.virtual_top,
			ScaleByZoom(left - vp.left, vp.zoom) + vp.virtual_left,
			ScaleByZoom((y + n) - vp.top, vp.zoom) + vp.virtual_top
		);
	}
}

/**
 * Construct a pathname for a screenshot file.