From 79de08db06d358c4aae243532d2e530e62780687 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Camilla=20L=C3=B6wy?= Date: Tue, 30 Nov 2021 20:34:47 +0100 Subject: [PATCH] Cleanup --- src/x11_window.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/src/x11_window.c b/src/x11_window.c index ea775cd4..a5255215 100644 --- a/src/x11_window.c +++ b/src/x11_window.c @@ -2115,20 +2115,19 @@ void _glfwSetWindowIconX11(_GLFWwindow* window, int count, const GLFWimage* imag for (int j = 0; j < images[i].width * images[i].height; j++) { - *target++ = (((unsigned long)images[i].pixels[j * 4 + 0]) << 16) | - (((unsigned long)images[i].pixels[j * 4 + 1]) << 8) | - (((unsigned long)images[i].pixels[j * 4 + 2]) << 0) | - (((unsigned long)images[i].pixels[j * 4 + 3]) << 24); + *target++ = (((unsigned long) images[i].pixels[j * 4 + 0]) << 16) | + (((unsigned long) images[i].pixels[j * 4 + 1]) << 8) | + (((unsigned long) images[i].pixels[j * 4 + 2]) << 0) | + (((unsigned long) images[i].pixels[j * 4 + 3]) << 24); } } - // Important: Despite XChangeProperty docs indicating that `icon` (unsigned char*) would be - // in the format of the icon image, e.g. 32-bit below, the function actually casts the ptr - // (unsigned char*) internally to (long*) and then if long is defined as 64-bits, as on IL64 - // platforms, extracts only 32 bits from the long leaving the other 32 unused. That is, on a - // 64-bit platform XChangeProperty expects 64-bit integers representing 32-bit pixels. - // - // See https://github.com/glfw/glfw/pull/1986#issuecomment-962445299 + // NOTE: XChangeProperty expects 32-bit values like the image data above to be + // placed in the 32 least significant bits of individual longs. This is + // true even if long is 64-bit and a WM protocol calls for "packed" data. + // This is because of a historical mistake that then became part of the Xlib + // ABI. Xlib will pack these values into a regular array of 32-bit values + // before sending it over the wire. XChangeProperty(_glfw.x11.display, window->x11.handle, _glfw.x11.NET_WM_ICON, XA_CARDINAL, 32,