win32 gui: mouse drag

initial implementation for left mouse drag

src/renderer/win32/renderer.zig

@@ -274,6 +274,39 @@ pub fn process_renderer_event(self: *Self, msg: []const u8) !void {
             return;
         }
     }
+    {
+        var args: struct {
+            pos: MousePos,
+            button_id: u8,
+        } = undefined;
+        if (try cbor.match(msg, .{
+            cbor.any,
+            "D",
+            cbor.extract(&args.button_id),
+            cbor.extract(&args.pos.col),
+            cbor.extract(&args.pos.row),
+            cbor.extract(&args.pos.xoffset),
+            cbor.extract(&args.pos.yoffset),
+        })) {
+            var buf: [200]u8 = undefined;
+            if (self.dispatch_mouse_drag) |f| f(
+                self.handler_ctx,
+                @intCast(args.pos.row),
+                @intCast(args.pos.col),
+                fmtmsg(&buf, .{
+                    "D",
+                    input.event.press,
+                    args.button_id,
+                    input.utils.button_id_string(@enumFromInt(args.button_id)),
+                    args.pos.col,
+                    args.pos.row,
+                    args.pos.xoffset,
+                    args.pos.yoffset,
+                }),
+            );
+            return;
+        }
+    }
     return error.UnexpectedRendererEvent;
 }
 

src/win32/gui.zig

@@ -588,6 +588,16 @@ pub fn fmtmsg(buf: []u8, value: anytype) []const u8 {
     return buf[0..fbs.pos];
 }
 
+const MouseFlags = packed struct(u8) {
+    left_down: bool,
+    right_down: bool,
+    shift_down: bool,
+    control_down: bool,
+    middle_down: bool,
+    xbutton1_down: bool,
+    xbutton2_down: bool,
+    _: bool,
+};
 fn sendMouse(
     hwnd: win32.HWND,
     kind: enum {
@@ -597,6 +607,7 @@ fn sendMouse(
         right_down,
         right_up,
     },
+    wparam: win32.WPARAM,
     lparam: win32.LPARAM,
 ) void {
     const point = ddui.pointFromLparam(lparam);
@@ -607,14 +618,25 @@ fn sendMouse(
     };
     const cell = CellPos.init(cell_size, point.x, point.y);
     switch (kind) {
-        .move => state.pid.send(.{
+        .move => {
+            const flags: MouseFlags = @bitCast(@as(u8, @intCast(0xff & wparam)));
+            if (flags.left_down) state.pid.send(.{
+                "RDR",
+                "D",
+                @intFromEnum(input.mouse.BUTTON1),
+                cell.cell.x,
+                cell.cell.y,
+                cell.offset.x,
+                cell.offset.y,
+            }) catch |e| onexit(e) else state.pid.send(.{
                 "RDR",
                 "M",
                 cell.cell.x,
                 cell.cell.y,
                 cell.offset.x,
                 cell.offset.y,
-        }) catch |e| onexit(e),
+            }) catch |e| onexit(e);
+        },
         else => |b| state.pid.send(.{
             "RDR",
             "B",
@@ -953,23 +975,23 @@ fn WndProc(
 
     switch (msg) {
         win32.WM_MOUSEMOVE => {
-            sendMouse(hwnd, .move, lparam);
+            sendMouse(hwnd, .move, wparam, lparam);
             return 0;
         },
         win32.WM_LBUTTONDOWN => {
-            sendMouse(hwnd, .left_down, lparam);
+            sendMouse(hwnd, .left_down, wparam, lparam);
             return 0;
         },
         win32.WM_LBUTTONUP => {
-            sendMouse(hwnd, .left_up, lparam);
+            sendMouse(hwnd, .left_up, wparam, lparam);
             return 0;
         },
         win32.WM_RBUTTONDOWN => {
-            sendMouse(hwnd, .right_down, lparam);
+            sendMouse(hwnd, .right_down, wparam, lparam);
             return 0;
         },
         win32.WM_RBUTTONUP => {
-            sendMouse(hwnd, .right_up, lparam);
+            sendMouse(hwnd, .right_up, wparam, lparam);
             return 0;
         },
         win32.WM_MOUSEWHEEL => {