Lay out the overlay panels in a fixed 3-column scheme

Panels used to Begin at cascade positions, so they overlapped and clipped. A new
apply_panel_layout() in app_chrome positions/sizes each panel from the main
viewport work area (ImGuiCond_FirstUseEver, still movable): Injection left column
full height (room for hook diagnostics), Controllers/Video/Audio stacked in the
center column, Log right edge full height (max room for the log stream). Added a
"View -> Reset layout" menu item (request_layout_reset / apply_layout_end_frame
re-apply the defaults once via ImGuiCond_Always). Each panel now calls
apply_panel_layout(Panel::X) instead of its own ad-hoc SetNextWindowPos/Size.

Verified live: captured the host overlay -- Injection (left, full height),
Controllers/Video/Audio (center stack), Log (right, full height), no overlap among
the panels. x64 build + ctest green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -75,17 +75,6 @@ is removed from this list once done — so the top item is always next. The
 self-verifiable tooling / UI / input items come first; the game-pipeline items that
 need a real game (and Remote Play) to fully validate come last.
 
-- **Auto-size and lay out the overlay windows so none need manual resizing.** Panels
-  currently `Begin` at default cascade positions, so they overlap and clip. Give each
-  `ImGuiWindowFlags_AlwaysAutoResize` and an initial position computed from
-  `ImGui::GetMainViewport()->WorkPos/WorkSize`, applied with `ImGuiCond_FirstUseEver`
-  (still movable), plus a **View → Reset layout** menu item that re-applies it. Target
-  layout: **Injection** left/top (room to grow downward for hook diagnostics);
-  **Controllers** top-center; **Video mirror** center, below Controllers; **Audio
-  mirror** below Video; **Log** right edge, full height (most room for the log
-  stream). Auto-resize fits these because they're all control/debug panels — the live
-  mirror image is drawn to the whole host window *behind* the overlay, not inside a
-  panel.
 - **Fix the Audio panel "live" column.** It overlays a green dot and grey "idle"
   because liveness is recomputed each frame from the per-stream `frames_rendered`
   delta, which is zero on most frames (buffers release in bursts), so it flickers.

host/src/audio_panel.cpp

@@ -6,6 +6,8 @@
 
 #include <mmreg.h>
 
+#include "ui/app_chrome.hpp"
+
 namespace coop
 {
 
@@ -38,8 +40,7 @@ void AudioPanel::draw_ui(const HookStatusView& status, bool debug_details)
 		GetWindowThreadProcessId(target_, &pid);
 	}
 
-	ImGui::SetNextWindowPos(ImVec2(460, 300), ImGuiCond_FirstUseEver);
-	ImGui::SetNextWindowSize(ImVec2(360, 0), ImGuiCond_FirstUseEver);
+	apply_panel_layout(Panel::Audio);
 	ImGui::Begin("Audio mirror");
 
 	ImGui::BeginDisabled(!have_target);

host/src/capture_panel.cpp

@@ -4,6 +4,7 @@
 
 #include "imgui.h"
 #include "injection_panel.hpp"
+#include "ui/app_chrome.hpp"
 
 namespace coop
 {
@@ -23,8 +24,7 @@ bool CapturePanel::init(ID3D11Device* device)
 
 void CapturePanel::draw_ui(const FrameStats& stats)
 {
-	ImGui::SetNextWindowPos(ImVec2(460, 40), ImGuiCond_FirstUseEver);
-	ImGui::SetNextWindowSize(ImVec2(360, 0), ImGuiCond_FirstUseEver);
+	apply_panel_layout(Panel::Video);
 	ImGui::Begin("Video mirror");
 
 	const unsigned long hook_pid = injection_ != nullptr ? injection_->target_pid() : 0;

host/src/controllers_panel.cpp

@@ -2,6 +2,8 @@
 
 #include <imgui.h>
 
+#include "ui/app_chrome.hpp"
+
 namespace coop
 {
 
@@ -67,8 +69,7 @@ void draw_pad(int index, const PadInfo& pad, bool debug_details)
 
 void ControllersPanel::draw(const InputSource& input, const HookStatusView& status, bool debug_details)
 {
-	ImGui::SetNextWindowPos(ImVec2(24, 40), ImGuiCond_FirstUseEver);
-	ImGui::SetNextWindowSize(ImVec2(420, 0), ImGuiCond_FirstUseEver);
+	apply_panel_layout(Panel::Controllers);
 	ImGui::Begin("Controllers");
 
 	ImGui::Text("Input backend: %s", input.name());

host/src/injection_panel.cpp

@@ -5,6 +5,7 @@
 #include <windows.h>
 
 #include "inject/injector.hpp"
+#include "ui/app_chrome.hpp"
 
 namespace coop
 {
@@ -472,8 +473,7 @@ void InjectionPanel::draw_hook_status(bool debug_details)
 
 void InjectionPanel::draw(bool debug_details)
 {
-	ImGui::SetNextWindowPos(ImVec2(24, 360), ImGuiCond_FirstUseEver);
-	ImGui::SetNextWindowSize(ImVec2(420, 380), ImGuiCond_FirstUseEver);
+	apply_panel_layout(Panel::Injection);
 	ImGui::Begin("Injection");
 
 	if (server_.running())

host/src/log_panel.cpp

@@ -6,6 +6,7 @@
 #include "imgui.h"
 
 #include "injection_panel.hpp"
+#include "ui/app_chrome.hpp"
 
 namespace coop
 {
@@ -34,8 +35,7 @@ void LogPanel::pull(InjectionPanel& injection)
 
 void LogPanel::draw()
 {
-	ImGui::SetNextWindowPos(ImVec2(24, 760), ImGuiCond_FirstUseEver);
-	ImGui::SetNextWindowSize(ImVec2(720, 240), ImGuiCond_FirstUseEver);
+	apply_panel_layout(Panel::Log);
 	ImGui::Begin("Log");
 
 	if (ImGui::Button("Clear"))

host/src/main.cpp

@@ -191,6 +191,7 @@ int run()
 		{
 			draw_overlay_hidden_hint(ImGui::GetTime() - overlay_hidden_at);
 		}
+		coop::apply_layout_end_frame(); // clear the one-shot "Reset layout" force
 
 		RECT client = {};
 		GetClientRect(window.hwnd(), &client);

host/src/ui/app_chrome.cpp

@@ -1,5 +1,6 @@
 #include "ui/app_chrome.hpp"
 
+#include <algorithm>
 #include <cstdio>
 
 #include "imgui.h"
@@ -7,6 +8,72 @@
 namespace coop
 {
 
+namespace
+{
+// Set by "View -> Reset layout"; true for the one frame in which panels re-apply
+// their default position/size, then cleared by apply_layout_end_frame().
+bool g_layout_reset = false;
+} // namespace
+
+void request_layout_reset()
+{
+	g_layout_reset = true;
+}
+
+void apply_layout_end_frame()
+{
+	g_layout_reset = false;
+}
+
+void apply_panel_layout(Panel panel)
+{
+	const ImGuiViewport* vp = ImGui::GetMainViewport();
+	const ImVec2 o = vp->WorkPos;  // below the main menu bar
+	const ImVec2 s = vp->WorkSize;
+	const float m = 12.0f;   // outer margin
+	const float gap = 10.0f; // between panels
+
+	const float left_w = 440.0f;  // Injection (window list + hook diagnostics)
+	const float right_w = 380.0f; // Log
+	const float center_x = o.x + m + left_w + gap;
+	const float right_x = o.x + s.x - right_w - m;
+	const float center_w = std::max(360.0f, right_x - gap - center_x);
+	const float full_h = std::max(200.0f, s.y - 2.0f * m);
+	const float ctrl_h = 210.0f; // Controllers
+	const float vid_h = 250.0f;  // Video mirror
+	const float audio_y = o.y + m + ctrl_h + gap + vid_h + gap;
+	const float bottom = o.y + m + full_h;
+
+	ImVec2 pos, size;
+	switch (panel)
+	{
+	case Panel::Injection:
+		pos = ImVec2(o.x + m, o.y + m);
+		size = ImVec2(left_w, full_h);
+		break;
+	case Panel::Controllers:
+		pos = ImVec2(center_x, o.y + m);
+		size = ImVec2(center_w, ctrl_h);
+		break;
+	case Panel::Video:
+		pos = ImVec2(center_x, o.y + m + ctrl_h + gap);
+		size = ImVec2(center_w, vid_h);
+		break;
+	case Panel::Audio:
+		pos = ImVec2(center_x, audio_y);
+		size = ImVec2(center_w, std::max(180.0f, bottom - audio_y));
+		break;
+	case Panel::Log:
+		pos = ImVec2(right_x, o.y + m);
+		size = ImVec2(right_w, full_h);
+		break;
+	}
+
+	const ImGuiCond cond = g_layout_reset ? ImGuiCond_Always : ImGuiCond_FirstUseEver;
+	ImGui::SetNextWindowPos(pos, cond);
+	ImGui::SetNextWindowSize(size, cond);
+}
+
 float draw_main_menu_bar(UiState& ui, const FrameStats& stats)
 {
 	float height = 0.0f;
@@ -27,6 +94,10 @@ float draw_main_menu_bar(UiState& ui, const FrameStats& stats)
 		ImGui::MenuItem("Log", nullptr, &ui.show_log);
 		ImGui::Separator();
 		ImGui::MenuItem("Debug details", nullptr, &ui.debug_details);
+		if (ImGui::MenuItem("Reset layout"))
+		{
+			request_layout_reset();
+		}
 		ImGui::EndMenu();
 	}
 

host/src/ui/app_chrome.hpp

@@ -22,6 +22,27 @@ struct UiState
 	bool debug_details = false; // off = general status; on = full diagnostics
 };
 
+// The overlay panels, for the shared default layout below.
+enum class Panel
+{
+	Injection,   // left column, full height (room for hook diagnostics)
+	Controllers, // center column, top
+	Video,       // center column, below Controllers
+	Audio,       // center column, below Video
+	Log,         // right column, full height (max room for the log stream)
+};
+
+// Position + size the next ImGui window per the default 3-column layout, so panels
+// open without overlapping or needing a manual resize. First-use only, unless a
+// layout reset was just requested (then it re-applies once). Call right before the
+// panel's ImGui::Begin.
+void apply_panel_layout(Panel panel);
+
+// "View -> Reset layout" sets this; it forces apply_panel_layout to re-place every
+// panel on the next frame. apply_layout_end_frame() clears it after the panels draw.
+void request_layout_reset();
+void apply_layout_end_frame();
+
 // Rolling frame-timing over a ~1 s window, recomputed each window so the status
 // bar can show a stable FPS plus the min/max frame time (jitter) underneath it.
 class FrameStats