Frame graph + Precise 60 fps timing (#998)

* video info: add frame graph

Toggle advanced info with CTRL+F10.
Also fixed imgui using gamepad for nav in wrong situations

* 60fps!

Implemented a timer that accumulates the time spent sleeping and sleeps for the remaining time.
Also measure entire PresentThread time instead of just the time spent in Flip.

* sceKernelGettimeofday: replace chrono by win32 api. Better performance

bb uses this function too much. Consuming almost 30% of cpu time

src/imgui/layer/video_info.cpp

@@ -2,16 +2,121 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <imgui.h>
+
+#include "common/config.h"
+#include "common/types.h"
+#include "imgui_internal.h"
 #include "video_info.h"
 
-void ImGui::Layers::VideoInfo::Draw() {
-    const ImGuiIO& io = GetIO();
+using namespace ImGui;
 
-    m_show = IsKeyPressed(ImGuiKey_F10, false) ^ m_show;
+struct FrameInfo {
+    u32 num;
+    float delta;
+};
 
-    if (m_show) {
-        if (Begin("Video Info", 0, ImGuiWindowFlags_NoNav)) {
-            Text("Frame time: %.3f ms (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+static bool show = false;
+static bool show_advanced = false;
+
+static u32 current_frame = 0;
+constexpr float TARGET_FPS = 60.0f;
+constexpr u32 FRAME_BUFFER_SIZE = 1024;
+constexpr float BAR_WIDTH_MULT = 1.4f;
+constexpr float BAR_HEIGHT_MULT = 1.25f;
+constexpr float FRAME_GRAPH_PADDING_Y = 3.0f;
+static std::array<FrameInfo, FRAME_BUFFER_SIZE> frame_list;
+static float frame_graph_height = 50.0f;
+
+static void DrawSimple() {
+    const auto io = GetIO();
+    Text("Frame time: %.3f ms (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+}
+
+static void DrawAdvanced() {
+    const auto& ctx = *GetCurrentContext();
+    const auto& io = ctx.IO;
+    const auto& window = *ctx.CurrentWindow;
+    auto& draw_list = *window.DrawList;
+
+    Text("Frame time: %.3f ms (%.1f FPS)", io.DeltaTime * 1000.0f, io.Framerate);
+
+    SeparatorText("Frame graph");
+    const float full_width = GetContentRegionAvail().x;
+    { // Frame graph - inspired by
+      // https://asawicki.info/news_1758_an_idea_for_visualization_of_frame_times
+        auto pos = GetCursorScreenPos();
+        const ImVec2 size{full_width, frame_graph_height + FRAME_GRAPH_PADDING_Y * 2.0f};
+        ItemSize(size);
+        if (!ItemAdd({pos, pos + size}, GetID("FrameGraph"))) {
+            return;
+        }
+
+        float target_dt = 1.0f / (TARGET_FPS * (float)Config::vblankDiv());
+        float cur_pos_x = pos.x + full_width;
+        pos.y += FRAME_GRAPH_PADDING_Y;
+        const float final_pos_y = pos.y + frame_graph_height;
+
+        draw_list.AddRectFilled({pos.x, pos.y - FRAME_GRAPH_PADDING_Y},
+                                {pos.x + full_width, final_pos_y + FRAME_GRAPH_PADDING_Y},
+                                IM_COL32(0x33, 0x33, 0x33, 0xFF));
+        draw_list.PushClipRect({pos.x, pos.y}, {pos.x + full_width, final_pos_y}, true);
+        for (u32 i = 0; i < FRAME_BUFFER_SIZE; ++i) {
+            const auto& frame_info = frame_list[(current_frame - i) % FRAME_BUFFER_SIZE];
+            const float dt_factor = target_dt / frame_info.delta;
+
+            const float width = std::ceil(BAR_WIDTH_MULT / dt_factor);
+            const float height =
+                std::min(std::log2(BAR_HEIGHT_MULT / dt_factor) / 3.0f, 1.0f) * frame_graph_height;
+
+            ImU32 color;
+            if (dt_factor >= 0.95f) { // BLUE
+                color = IM_COL32(0x33, 0x33, 0xFF, 0xFF);
+            } else if (dt_factor >= 0.5f) { // GREEN <> YELLOW
+                float t = 1.0f - (dt_factor - 0.5f) * 2.0f;
+                int r = (int)(0xFF * t);
+                color = IM_COL32(r, 0xFF, 0, 0xFF);
+            } else { // YELLOW <> RED
+                float t = dt_factor * 2.0f;
+                int g = (int)(0xFF * t);
+                color = IM_COL32(0xFF, g, 0, 0xFF);
+            }
+            draw_list.AddRectFilled({cur_pos_x - width, final_pos_y - height},
+                                    {cur_pos_x, final_pos_y}, color);
+            cur_pos_x -= width;
+            if (cur_pos_x < width) {
+                break;
+            }
+        }
+        draw_list.PopClipRect();
+    }
+}
+
+void Layers::VideoInfo::Draw() {
+    const auto io = GetIO();
+
+    const FrameInfo frame_info{
+        .num = ++current_frame,
+        .delta = io.DeltaTime,
+    };
+    frame_list[current_frame % FRAME_BUFFER_SIZE] = frame_info;
+
+    if (IsKeyPressed(ImGuiKey_F10, false)) {
+        const bool changed_ctrl = io.KeyCtrl != show_advanced;
+        show_advanced = io.KeyCtrl;
+        show = changed_ctrl || !show;
+    }
+
+    if (show) {
+        if (show_advanced) {
+            if (Begin("Video debug info", &show, 0)) {
+                DrawAdvanced();
+            }
+        } else {
+            if (Begin("Video Info", nullptr,
+                      ImGuiWindowFlags_NoNav | ImGuiWindowFlags_NoDecoration |
+                          ImGuiWindowFlags_AlwaysAutoResize)) {
+                DrawSimple();
+            }
         }
         End();
     }

src/imgui/layer/video_info.h

@@ -11,7 +11,6 @@ class RendererVulkan;
 namespace ImGui::Layers {
 
 class VideoInfo : public Layer {
-    bool m_show = false;
     ::Vulkan::RendererVulkan* renderer{};
 
 public:

src/imgui/renderer/imgui_impl_sdl3.cpp

@@ -703,8 +703,8 @@ static void UpdateGamepads() {
     const int thumb_dead_zone = 8000; // SDL_gamepad.h suggests using this value.
     UpdateGamepadButton(bd, io, ImGuiKey_GamepadStart, SDL_GAMEPAD_BUTTON_START);
     UpdateGamepadButton(bd, io, ImGuiKey_GamepadBack, SDL_GAMEPAD_BUTTON_BACK);
-    UpdateGamepadButton(bd, io, ImGuiKey_GamepadFaceLeft,
-                        SDL_GAMEPAD_BUTTON_WEST); // Xbox X, PS Square
+    /*UpdateGamepadButton(bd, io, ImGuiKey_GamepadFaceLeft,
+                        SDL_GAMEPAD_BUTTON_WEST); // Xbox X, PS Square*/ // Disable to avoid menu toggle
     UpdateGamepadButton(bd, io, ImGuiKey_GamepadFaceRight,
                         SDL_GAMEPAD_BUTTON_EAST); // Xbox B, PS Circle
     UpdateGamepadButton(bd, io, ImGuiKey_GamepadFaceUp,