UX: Add CPU overclock and display rate override settings

These settings can be used to improve framerate or set a new framerate
limit (different from the typical 30/60 FPS).

Many games work well with this, but using overrides will break games
that are not designed around FPS-independent physics. Therefore, submitting
compatibility reports is disabled if either of the overrides are active.

Co-authored-by: Hugo Locurcio <hugo.locurcio@hugo.pro>

config_spec.yml

@@ -265,3 +265,15 @@ perf:
   cache_shaders:
     type: bool
     default: true
+  override_clockspeed:
+    type: bool
+    default: false
+  cpu_clockspeed_scale:
+    type: number
+    default: 1
+  override_display_rate:
+    type: bool
+    default: false
+  display_rate_scale:
+    type: number
+    default: 1

hw/i386/x86-cpu.c

@@ -31,11 +31,19 @@
 #include "hw/irq.h"
 #include "sysemu/kvm.h"
 
+#ifdef XBOX
+#include "ui/xemu-settings.h"
+#endif
+
 /* TSC handling */
 uint64_t cpu_get_tsc(CPUX86State *env)
 {
 #ifdef XBOX
-    return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 733333333,
+    float clockspeed_scale = 1.0f;
+    if (g_config.perf.override_clockspeed) {
+        clockspeed_scale = g_config.perf.cpu_clockspeed_scale;
+    }
+    return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 733333333 * clockspeed_scale,
                     NANOSECONDS_PER_SECOND);
 #else
     return cpus_get_elapsed_ticks();

ui/xemu.c

@@ -318,7 +318,7 @@ static void handle_keydown(SDL_Event *ev)
 {
     int win;
     struct sdl2_console *scon = get_scon_from_window(ev->key.windowID);
-    if (scon == NULL) return; 
+    if (scon == NULL) return;
     int gui_key_modifier_pressed = get_mod_state();
     int gui_keysym = 0;
 
@@ -1079,10 +1079,14 @@ void sdl2_gl_refresh(DisplayChangeListener *dcl)
     qemu_mutex_unlock_main_loop();
 
     /*
-     * Throttle to make sure swaps happen at 60Hz
+     * Throttle to make sure swaps happen at 60 Hz (divided by the display rate scale if overridden)
      */
     static int64_t last_update = 0;
-    int64_t deadline = last_update + 16666666;
+    float display_rate_scale = 1.0f;
+    if (g_config.perf.override_display_rate) {
+        display_rate_scale /= g_config.perf.display_rate_scale;
+    }
+    int64_t deadline = last_update + 16666666 * display_rate_scale;
 
 #ifdef DEBUG_XEMU_C
     int64_t sleep_acc = 0;

ui/xui/compat.cc

@@ -203,6 +203,14 @@ void CompatibilityReporter::Draw()
         ImGui::SameLine();
     }
 
+    if (g_config.perf.override_clockspeed || g_config.perf.override_display_rate) {
+        ImGui::PushItemFlag(ImGuiItemFlags_Disabled, true);
+        ImGui::PushStyleVar(ImGuiStyleVar_Alpha, ImGui::GetStyle().Alpha * 0.5f);
+
+        ImGui::Text("Reports cannot be made while using overridden CPU clock speed or display rate");
+        ImGui::SameLine();
+    }
+
     ImGui::SetCursorPosX(ImGui::GetWindowWidth()-(120+10)*g_viewport_mgr.m_scale);
 
     ImGui::SetItemDefaultFocus();
@@ -213,7 +221,10 @@ void CompatibilityReporter::Draw()
             is_open = false;
         }
     }
-
+    if (g_config.perf.override_clockspeed) {
+        ImGui::PopItemFlag();
+        ImGui::PopStyleVar();
+    }
     ImGui::End();
 }
 

ui/xui/main-menu.cc

@@ -66,6 +66,30 @@ void MainMenuGeneralView::Draw()
     Toggle("Cache shaders to disk", &g_config.perf.cache_shaders,
            "Reduce stutter in games by caching previously generated shaders");
 
+    SectionTitle("Tweaks");
+    Toggle("Emulated CPU clock override", &g_config.perf.override_clockspeed,
+           "Override default CPU clock speed (can break games)");
+
+    char cpu_clock_buf[32];
+    snprintf(cpu_clock_buf, sizeof(cpu_clock_buf), "Clock speed: %d%% (%.2f MHz)", (int)(g_config.perf.cpu_clockspeed_scale * 100), (733333333 * g_config.perf.cpu_clockspeed_scale) / 1000000);
+    Slider("Virtual CPU clock", &g_config.perf.cpu_clockspeed_scale, cpu_clock_buf, 0.25f, 4.f, 0.01f);
+
+    if (fabs(g_config.perf.cpu_clockspeed_scale - 1.f) <= 0.0099f) {
+        g_config.perf.cpu_clockspeed_scale = 1;
+    }
+
+    Toggle("Display rate override", &g_config.perf.override_display_rate,
+        "Override default presentation frame rate (can break games)");
+
+    char display_rate_buf[35];
+    snprintf(display_rate_buf, sizeof(display_rate_buf), "Display rate: %d%% (%d / %d FPS)", (int)(g_config.perf.display_rate_scale * 100), (int)(30 * g_config.perf.display_rate_scale), (int)(60 * g_config.perf.display_rate_scale));
+    // Set slider increment so that 60 FPS games can be adjusted at a per-FPS level in terms of precision
+    Slider("Display rate", &g_config.perf.display_rate_scale, display_rate_buf, 0.3333333f, 4.f, 0.0166667f);
+
+    if (fabs(g_config.perf.display_rate_scale - 1.f) <= 0.0099f) {
+        g_config.perf.display_rate_scale = 1;
+    }
+
     SectionTitle("Miscellaneous");
     Toggle("Skip startup animation", &g_config.general.skip_boot_anim,
            "Skip the full Xbox boot animation sequence");
@@ -172,14 +196,14 @@ void MainMenuInputView::Draw()
         driver = DRIVER_DUKE_DISPLAY_NAME;
     else if (strcmp(driver, DRIVER_S) == 0)
         driver = DRIVER_S_DISPLAY_NAME;
-    
+
     ImGui::SetNextItemWidth(-FLT_MIN);
     if (ImGui::BeginCombo("###InputDrivers", driver,
                           ImGuiComboFlags_NoArrowButton)) {
         const char *available_drivers[] = { DRIVER_DUKE, DRIVER_S };
-        const char *driver_display_names[] = { 
+        const char *driver_display_names[] = {
-            DRIVER_DUKE_DISPLAY_NAME, 
+            DRIVER_DUKE_DISPLAY_NAME,
-            DRIVER_S_DISPLAY_NAME 
+            DRIVER_S_DISPLAY_NAME
             };
         bool is_selected = false;
         int num_drivers = sizeof(driver_display_names) / sizeof(driver_display_names[0]);

ui/xui/widgets.cc

@@ -22,6 +22,7 @@
 #include "viewport-manager.hh"
 #include "ui/xemu-os-utils.h"
 #include "gl-helpers.hh"
+#include <algorithm>
 
 void Separator()
 {
@@ -222,8 +223,9 @@ bool Toggle(const char *str_id, bool *v, const char *description)
     return status;
 }
 
-void Slider(const char *str_id, float *v, const char *description)
+void Slider(const char *str_id, float *v, const char *description, float min, float max, float increment)
 {
+    float x = (*v - min) / (max - min);
     ImGui::PushStyleColor(ImGuiCol_Button, IM_COL32_BLACK_TRANS);
 
     ImGuiStyle &style = ImGui::GetStyle();
@@ -238,6 +240,8 @@ void Slider(const char *str_id, float *v, const char *description)
                 GetWidgetTitleDescriptionHeight(str_id, description));
     WidgetTitleDescription(str_id, description, p);
 
+    ImGui::PushID(str_id);
+
     // XXX: Internal API
     ImVec2 wpos = ImGui::GetCursorPos();
     ImRect bb(p, ImVec2(p.x + size.x, p.y + size.y));
@@ -261,13 +265,13 @@ void Slider(const char *str_id, float *v, const char *description)
             ImGui::IsKeyPressed(ImGuiKey_GamepadDpadLeft) ||
             ImGui::IsKeyPressed(ImGuiKey_GamepadLStickLeft) ||
             ImGui::IsKeyPressed(ImGuiKey_GamepadRStickLeft)) {
-                *v -= 0.05;
+                x -= increment / max;
         }
         if (ImGui::IsKeyPressed(ImGuiKey_RightArrow) ||
             ImGui::IsKeyPressed(ImGuiKey_GamepadDpadRight) ||
             ImGui::IsKeyPressed(ImGuiKey_GamepadLStickRight) ||
             ImGui::IsKeyPressed(ImGuiKey_GamepadRStickRight)) {
-                *v += 0.05;
+                x += increment / max;
         }
 
         if (
@@ -286,15 +290,17 @@ void Slider(const char *str_id, float *v, const char *description)
 
     if (ImGui::IsItemActive()) {
         ImVec2 mouse = ImGui::GetMousePos();
-        *v = GetSliderValueForMousePos(mouse, slider_pos, slider_size);
+        x = GetSliderValueForMousePos(mouse, slider_pos, slider_size);
     }
-    *v = fmax(0, fmin(*v, 1));
+    x = std::clamp(x, 0.f, 1.f);
-    DrawSlider(*v, ImGui::IsItemHovered() || ImGui::IsItemActive(), slider_pos,
+    *v = x * (max - min) + min;
+    DrawSlider(x, ImGui::IsItemHovered() || ImGui::IsItemActive(), slider_pos,
                slider_size);
 
     ImVec2 slider_max = ImVec2(slider_pos.x + slider_size.x, slider_pos.y + slider_size.y);
     ImGui::RenderNavHighlight(ImRect(slider_pos, slider_max), window->GetID("###slider"));
 
+    ImGui::PopID();
     ImGui::PopStyleColor();
 }
 

ui/xui/widgets.hh

@@ -34,7 +34,7 @@ float GetSliderValueForMousePos(ImVec2 mouse, ImVec2 pos, ImVec2 size);
 void DrawSlider(float v, bool hovered, ImVec2 pos, ImVec2 size);
 void DrawToggle(bool enabled, bool hovered, ImVec2 pos, ImVec2 size);
 bool Toggle(const char *str_id, bool *v, const char *description = nullptr);
-void Slider(const char *str_id, float *v, const char *description = nullptr);
+void Slider(const char *str_id, float *v, const char *description = nullptr, float min = 0, float max = 1, float increment = 0.05);
 bool FilePicker(const char *str_id, const char **buf, const char *filters,
                 bool dir = false);
 void DrawComboChevron();