finish GLFW impl

3 files changed, 108 insertions, 28 deletions

diff --git a/src/c.zig b/src/c.zig
index eeea35f..a4e20cc 100644
--- a/src/c.zig
+++ b/src/c.zig
@@ -1,5 +1,6 @@
 pub usingnamespace @cImport({
-    @cDefine("CIMGUI_DEFINE_ENUMS_AND_STRUCTS", "1");
-    @cInclude("cimgui.h");
-    @cInclude("GLFW/glfw3.h");
+  @cInclude("epoxy/gl.h");
+  @cDefine("CIMGUI_DEFINE_ENUMS_AND_STRUCTS", "1");
+  @cInclude("cimgui.h");
+  @cInclude("GLFW/glfw3.h");
 });
diff --git a/src/glfw_impl.zig b/src/glfw_impl.zig
index 7ef2f63..9b79374 100644
--- a/src/glfw_impl.zig
+++ b/src/glfw_impl.zig
@@ -10,16 +10,16 @@ pub const ClientApi = enum {
 var g_Window: ?*c.GLFWwindow = null;
 var g_ClientApi: ClientApi = .Unknown;
 var g_Time: f32 = 0.0;
-var g_MouseJustPressed = [5]bool;
-var g_MouseCursors = [_]?*c.GLFWcursor{null} ** @enumToInt(c.ImGuiMouseCursor_COUNT);
+var g_MouseJustPressed = [_]bool{ false } ** 5;
+var g_MouseCursors = [_]?*c.GLFWcursor{ null } ** @enumToInt(c.ImGuiMouseCursor_COUNT);
 var g_WantUpdateMonitors = true;
 
 // Chain GLFW callbacks for main viewport:
 // our callbacks will call the user's previously installed callbacks, if any.
-var g_PrevUserCallbackMousebutton: ?*c.GLFWmousebuttonfun = null;
-var g_PrevUserCallbackScroll: ?*c.GLFWscrollfun = null;
-var g_PrevUserCallbackKey: ?*c.GLFWkeyfun = null;
-var g_PrevUserCallbackChar: ?*c.GLFWcharfun = null;
+var g_PrevUserCallbackMousebutton: ?c.GLFWmousebuttonfun = null;
+var g_PrevUserCallbackScroll: ?c.GLFWscrollfun = null;
+var g_PrevUserCallbackKey: ?c.GLFWkeyfun = null;
+var g_PrevUserCallbackChar: ?c.GLFWcharfun = null;
 
 pub fn Init(window: *c.GLFWwindow, install_callbacks: bool, client_api: ClientApi) void {
   g_Window = window;
@@ -30,10 +30,10 @@ pub fn Init(window: *c.GLFWwindow, install_callbacks: bool, client_api: ClientAp
   io.*.BackendFlags |= @enumToInt(c.ImGuiBackendFlags_HasMouseCursors); // We can honor GetMouseCursor() values (optional)
   io.*.BackendFlags |= @enumToInt(c.ImGuiBackendFlags_HasSetMousePos); // We can honor io.WantSetMousePos requests (optional, rarely used)
   io.*.BackendFlags |= @enumToInt(c.ImGuiBackendFlags_PlatformHasViewports); // We can create multi-viewports on the Platform side (optional)
-  if (false and c.GLFW_HAS_GLFW_HOVERED and builtin.os == builtin.Os.windows) {
+  if (@hasField(c, "GLFW_HAS_GLFW_HOVERED") and builtin.os == builtin.Os.windows) {
     io.*.BackendFlags |= @enumToInt(ImGuiBackendFlags_HasMouseHoveredViewport); // We can set io.MouseHoveredViewport correctly (optional, not easy)
   }
-  io.*.BackendPlatformName = c"imgui_impl_glfw";
+  io.*.BackendPlatformName = c"imgui_impl_glfw.zig";
 
   // Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array.
   io.*.KeyMap[@enumToInt(c.ImGuiKey_Tab)] = c.GLFW_KEY_TAB;
@@ -59,6 +59,7 @@ pub fn Init(window: *c.GLFWwindow, install_callbacks: bool, client_api: ClientAp
   io.*.KeyMap[@enumToInt(c.ImGuiKey_Y)] = c.GLFW_KEY_Y;
   io.*.KeyMap[@enumToInt(c.ImGuiKey_Z)] = c.GLFW_KEY_Z;
 
+  // @TODO: Clipboard
   // io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
   // io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
   // io.ClipboardUserData = g_Window;
@@ -77,11 +78,11 @@ pub fn Init(window: *c.GLFWwindow, install_callbacks: bool, client_api: ClientAp
   g_PrevUserCallbackScroll = null;
   g_PrevUserCallbackKey = null;
   g_PrevUserCallbackChar = null;
-  if (install_callbacks and false) {
-    // g_PrevUserCallbackMousebutton = glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback);
-    // g_PrevUserCallbackScroll = glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback);
-    // g_PrevUserCallbackKey = glfwSetKeyCallback(window, ImGui_ImplGlfw_KeyCallback);
-    // g_PrevUserCallbackChar = glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback);
+  if (install_callbacks) {
+    g_PrevUserCallbackMousebutton = c.glfwSetMouseButtonCallback(window, Callback_MouseButton);
+    g_PrevUserCallbackScroll = c.glfwSetScrollCallback(window, Callback_Scroll);
+    g_PrevUserCallbackKey = c.glfwSetKeyCallback(window, Callback_Key);
+    g_PrevUserCallbackChar = c.glfwSetCharCallback(window, Callback_Char);
   }
 
   // Our mouse update function expect PlatformHandle to be filled for the main viewport
@@ -91,6 +92,7 @@ pub fn Init(window: *c.GLFWwindow, install_callbacks: bool, client_api: ClientAp
     main_viewport.*.PlatformHandleRaw = c.glfwGetWin32Window(g_Window);
   }
 
+  // @TODO: Platform Interface (Viewport)
   // if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable != 0)
   //    ImGui_ImplGlfw_InitPlatformInterface();
 
@@ -98,10 +100,73 @@ pub fn Init(window: *c.GLFWwindow, install_callbacks: bool, client_api: ClientAp
 }
 
 pub fn Shutdown() void {
+  // @TODO: Platform Interface (Viewport)
   // ImGui_ImplGlfw_ShutdownPlatformInterface();
+
   for (g_MouseCursors) |*cursor| {
     c.glfwDestroyCursor(cursor.*);
     cursor.* = null;
   }
   g_ClientApi = .Unknown;
 }
+
+pub fn NewFrame() void {
+  const io = c.igGetIO();
+  // @TODO: assert font atlas
+
+  var w : c_int = undefined;
+  var h : c_int = undefined;
+  var display_w : c_int = undefined;
+  var display_h : c_int = undefined;
+  c.glfwGetWindowSize(g_Window, &w, &h);
+  c.glfwGetFramebufferSize(g_Window, &display_w, &display_h);
+  io.*.DisplaySize = c.ImVec2{ .x = @intToFloat(f32, w), .y = @intToFloat(f32, h) };
+}
+
+// GLFW Callbacks
+extern fn Callback_MouseButton(window: ?*c.GLFWwindow, button: c_int, action: c_int, mods: c_int) void {
+  // @TODO: delegate up
+
+  if (button < 0) 
+    return;
+
+  const button_u = @intCast(usize, button);
+  if (action == c.GLFW_PRESS and button_u < g_MouseJustPressed.len)
+    g_MouseJustPressed[button_u] = true;
+}
+
+extern fn Callback_Scroll(window: ?*c.GLFWwindow, dx: f64, dy: f64) void {
+  // @TODO: delegate up
+
+  const io = c.igGetIO();
+  io.*.MouseWheelH += @floatCast(f32, dx);
+  io.*.MouseWheel  += @floatCast(f32, dy);
+}
+
+extern fn Callback_Key(window: ?*c.GLFWwindow, key: c_int, scancode: c_int, action: c_int, modifiers: c_int) void {
+  // @TODO: delegate up
+
+  if (key < 0)
+    unreachable;
+
+  const key_u = @intCast(usize, key);
+
+  const io = c.igGetIO();
+  if (action == c.GLFW_PRESS)
+    io.*.KeysDown[key_u] = true;
+  if (action == c.GLFW_RELEASE)
+    io.*.KeysDown[key_u] = false;
+
+  // Modifiers are not reliable across systems
+  io.*.KeyCtrl = io.*.KeysDown[c.GLFW_KEY_LEFT_CONTROL] or io.*.KeysDown[c.GLFW_KEY_RIGHT_CONTROL];
+  io.*.KeyShift = io.*.KeysDown[c.GLFW_KEY_LEFT_SHIFT] or io.*.KeysDown[c.GLFW_KEY_RIGHT_SHIFT];
+  io.*.KeyAlt = io.*.KeysDown[c.GLFW_KEY_LEFT_ALT] or io.*.KeysDown[c.GLFW_KEY_RIGHT_ALT];
+  io.*.KeySuper = io.*.KeysDown[c.GLFW_KEY_LEFT_SUPER] or io.*.KeysDown[c.GLFW_KEY_RIGHT_SUPER];
+}
+
+extern fn Callback_Char(window: ?*c.GLFWwindow, char: c_uint) void {
+  // @TODO: delegate up
+
+  const io = c.igGetIO();
+  c.ImGuiIO_AddInputCharacter(io, char);
+}
diff --git a/src/main.zig b/src/main.zig
index 42fa152..08f5bea 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -4,7 +4,7 @@ const panic = std.debug.panic;
 const glfw_impl = @import("glfw_impl.zig");
 
 extern fn errorCallback(err: c_int, description: [*c]const u8) void {
-      panic("Error: {}\n", description);
+  panic("Error: {}\n", description);
 }
 
 var window: *c.GLFWwindow = undefined;
@@ -13,7 +13,7 @@ pub fn main() void {
   _ = c.glfwSetErrorCallback(errorCallback);
 
   if (c.glfwInit() == c.GL_FALSE) {
-      panic("GLFW init failure\n");
+    panic("GLFW init failure\n");
   }
   defer c.glfwTerminate();
 
@@ -30,7 +30,7 @@ pub fn main() void {
   const window_width = 640;
   const window_height = 480;
   window = c.glfwCreateWindow(window_width, window_height, c"ImGUI Test", null, null) orelse {
-      panic("unable to create window\n");
+    panic("unable to create window\n");
   };
   defer c.glfwDestroyWindow(window);
 
@@ -54,24 +54,38 @@ pub fn main() void {
   }
 
   glfw_impl.Init(window, true, glfw_impl.ClientApi.OpenGL);
-  // ImGui_InitForOpenGL(window, true);
+  defer glfw_impl.Shutdown();
+
   // ImGui_ImplOpenGL3_Init(glsl_version);
 
   const start_time = c.glfwGetTime();
   var prev_time = start_time;
 
   while (c.glfwWindowShouldClose(window) == c.GL_FALSE) {
-    // c.glClear(c.GL_COLOR_BUFFER_BIT | c.GL_DEPTH_BUFFER_BIT | c.GL_STENCIL_BUFFER_BIT);
-
-    const now_time = c.glfwGetTime();
-    const elapsed = now_time - prev_time;
-    prev_time = now_time;
+    c.glfwPollEvents();
 
+    glfw_impl.NewFrame();
+    // gl3_impl.NewFrame();
+    c.igNewFrame();
+
+    // main part
+    c.igShowDemoWindow(null);
+
+    c.igRender();
+    var w: c_int = undefined;
+    var h: c_int = undefined;
+    c.glfwGetFramebufferSize(window, &w, &h);
+    c.glViewport(0, 0, w, h);
+    c.glClearColor(0.0, 0.0, 0.0, 0.0);
+    c.glClear(c.GL_COLOR_BUFFER_BIT);
+    // gl3_impl.RenderDrawData(c.igGetDrawData());
+
+    // const now_time = c.glfwGetTime();
+    // const elapsed = now_time - prev_time;
+    // prev_time = now_time;
     // nextFrame(t, elapsed);
-
     // draw(t, @This());
+    
     c.glfwSwapBuffers(window);
-
-    c.glfwPollEvents();
   }
 }