Merge pull request #8 from MirkoCovizzi/master

Add OpenGL context on Windows

Cargo.toml

@@ -15,7 +15,8 @@ edition = "2018"
 xcb = { version = "0.9", features = ["thread", "xlib_xcb", "dri2"] }
 
 [target.'cfg(target_os="windows")'.dependencies]
-winapi = { version = "0.3.8", features = ["libloaderapi", "winuser", "windef", "minwindef", "guiddef", "combaseapi"] }
+winapi = { version = "0.3.8", features = ["libloaderapi", "winuser", "windef", "minwindef", "guiddef", "combaseapi", "wingdi"] }
+gl = "0.14.0"
 
 [target.'cfg(target_os="macos")'.dependencies]
 cocoa = "0.20.1"

src/win/window.rs

@@ -1,15 +1,20 @@
 extern crate winapi;
 
+use std::ffi::CString;
 use std::ptr::null_mut;
 
-use self::winapi::_core::mem::MaybeUninit;
 use self::winapi::shared::guiddef::GUID;
-use self::winapi::shared::minwindef::{LPARAM, LPVOID, LRESULT, UINT, WPARAM};
+use self::winapi::shared::minwindef::{LPARAM, LRESULT, UINT, WPARAM};
-use self::winapi::shared::windef::{HBRUSH, HICON, HMENU, HWND};
+use self::winapi::shared::windef::{HGLRC, HWND};
 use self::winapi::um::combaseapi::CoCreateGuid;
-use self::winapi::um::libloaderapi::GetModuleHandleA;
+use self::winapi::um::libloaderapi::{GetProcAddress, LoadLibraryA};
+use self::winapi::um::wingdi::{
+    wglCreateContext, wglMakeCurrent, ChoosePixelFormat, SetPixelFormat, SwapBuffers,
+    PFD_DOUBLEBUFFER, PFD_DRAW_TO_WINDOW, PFD_MAIN_PLANE, PFD_SUPPORT_OPENGL, PFD_TYPE_RGBA,
+    PIXELFORMATDESCRIPTOR,
+};
 use self::winapi::um::winuser::{
-    CreateWindowExA, DefWindowProcA, DispatchMessageA, PeekMessageA, PostQuitMessage,
+    CreateWindowExA, DefWindowProcA, DispatchMessageA, GetDC, PeekMessageA, PostQuitMessage,
     RegisterClassA, TranslateMessage, CS_HREDRAW, CS_OWNDC, CS_VREDRAW, CW_USEDEFAULT, MSG,
     PM_REMOVE, WM_DESTROY, WM_QUIT, WNDCLASSA, WS_OVERLAPPEDWINDOW, WS_VISIBLE,
 };
@@ -19,10 +24,11 @@ use crate::WindowOpenOptions;
 pub struct Window;
 
 impl Window {
+    // todo: we should decide this interface
     pub fn open(options: WindowOpenOptions) -> Self {
         unsafe {
             // We generate a unique name for the new window class to prevent name collisions
-            let mut guid: GUID = MaybeUninit::uninit().assume_init();
+            let mut guid: GUID = std::mem::zeroed();
             CoCreateGuid(&mut guid);
             let class_name = format!(
                 "Baseview-{:0X}-{:0X}-{:0X}-{:0X}{:0X}-{:0X}{:0X}{:0X}{:0X}{:0X}{:0X}\0",
@@ -39,23 +45,22 @@ impl Window {
                 guid.Data4[7]
             );
 
-            let hinstance = GetModuleHandleA(0 as *const i8);
             let wnd_class = WNDCLASSA {
                 // todo: for OpenGL, will use it later
                 style: CS_OWNDC | CS_HREDRAW | CS_VREDRAW,
                 lpfnWndProc: Some(wnd_proc),
-                hInstance: hinstance,
+                hInstance: null_mut(),
                 lpszClassName: class_name.as_ptr() as *const i8,
                 cbClsExtra: 0,
                 cbWndExtra: 0,
-                hIcon: 0 as HICON,
+                hIcon: null_mut(),
-                hCursor: 0 as HICON,
+                hCursor: null_mut(),
-                hbrBackground: 0 as HBRUSH,
+                hbrBackground: null_mut(),
-                lpszMenuName: 0 as *const i8,
+                lpszMenuName: std::ptr::null::<i8>(),
             };
             RegisterClassA(&wnd_class);
 
-            let _hwnd = CreateWindowExA(
+            let hwnd = CreateWindowExA(
                 0,
                 class_name.as_ptr() as *const i8,
                 (options.title.to_owned() + "\0").as_ptr() as *const i8,
@@ -66,16 +71,60 @@ impl Window {
                 // todo: check if usize fits into i32
                 options.width as i32,
                 options.height as i32,
-                0 as HWND,
+                null_mut(),
-                0 as HMENU,
+                null_mut(),
-                hinstance,
+                null_mut(),
-                0 as LPVOID,
+                null_mut(),
             );
 
+            let hdc = GetDC(hwnd);
+
+            let mut pfd: PIXELFORMATDESCRIPTOR = std::mem::zeroed();
+            pfd.nSize = std::mem::size_of::<PIXELFORMATDESCRIPTOR>() as u16;
+            pfd.nVersion = 1;
+            pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
+            pfd.iPixelType = PFD_TYPE_RGBA;
+            pfd.cColorBits = 32;
+            // todo: ask wrl why 24 instead of 32?
+            pfd.cDepthBits = 24;
+            pfd.cStencilBits = 8;
+            pfd.iLayerType = PFD_MAIN_PLANE;
+
+            let pf_id: i32 = ChoosePixelFormat(hdc, &pfd);
+            if pf_id == 0 {
+                return Window;
+            }
+
+            if SetPixelFormat(hdc, pf_id, &pfd) == 0 {
+                return Window;
+            }
+
+            let gl_context: HGLRC = wglCreateContext(hdc);
+            if gl_context == 0 as HGLRC {
+                return Window;
+            }
+
+            if wglMakeCurrent(hdc, gl_context) == 0 {
+                return Window;
+            }
+
+            let h = LoadLibraryA("opengl32.dll\0".as_ptr() as *const i8);
+            gl::load_with(|symbol| {
+                let symbol = CString::new(symbol.as_bytes()).unwrap();
+                let symbol = symbol.as_ptr();
+                GetProcAddress(h, symbol) as *const _
+            });
+
+            // todo: decide what to do with the message pump
             loop {
                 if !handle_msg(null_mut()) {
                     break;
                 }
+
+                // todo: pass callback rendering function instead
+                gl::ClearColor(0.3, 0.8, 0.3, 1.0);
+                gl::Clear(gl::COLOR_BUFFER_BIT);
+                SwapBuffers(hdc);
             }
         }
 
@@ -85,7 +134,7 @@ impl Window {
 
 fn handle_msg(_window: HWND) -> bool {
     unsafe {
-        let mut msg: MSG = MaybeUninit::uninit().assume_init();
+        let mut msg: MSG = std::mem::zeroed();
         loop {
             if PeekMessageA(&mut msg, 0 as HWND, 0, 0, PM_REMOVE) == 0 {
                 return true;
@@ -113,5 +162,5 @@ unsafe extern "system" fn wnd_proc(
             return DefWindowProcA(hwnd, msg, w_param, l_param);
         }
     }
-    return 0;
+    0
 }