GTE: Make widescreen hack use display aspect ratio

README.md

@@ -13,6 +13,7 @@ A "BIOS" ROM image is required to to start the emulator and to play games. You c
 
 ## Latest News
 
+- 2020/11/10: Widescreen hack now renders in the display aspect ratio instead of always 16:9.
 - 2020/11/01: Exclusive fullscreen option added for Windows D3D11 users. Enjoy buttery smooth PAL games.
 - 2020/10/31: Multisample antialiasing added as an enhancement.
 - 2020/10/30: Option to use analog stick as d-pad for analog controller added.

src/core/gte.cpp

@@ -613,10 +613,52 @@ static void RTPS(const s16 V[3], u8 shift, bool lm, bool last)
   // MAC0=(((H*20000h/SZ3)+1)/2)*IR2+OFY, SY2=MAC0/10000h ;ScrY FIFO -400h..+3FFh
   const s64 result = static_cast<s64>(ZeroExtend64(UNRDivide(REGS.H, REGS.SZ3)));
 
-  // (4 / 3) / (16 / 9) -> 0.75 -> (3 / 4)
+  s64 Sx;
-  const s64 Sx = g_settings.gpu_widescreen_hack ?
+  if (g_settings.gpu_widescreen_hack)
-                   ((((s64(result) * s64(REGS.IR1)) * s64(3)) / s64(4)) + s64(REGS.OFX)) :
+  {
-                   (s64(result) * s64(REGS.IR1) + s64(REGS.OFX));
+    const DisplayAspectRatio ar = g_settings.display_aspect_ratio;
+    switch (ar)
+    {
+      case DisplayAspectRatio::R16_9:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(3)) / s64(4)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R16_10:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(5)) / s64(6)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R19_9:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(12)) / s64(19)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R21_9:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(4)) / s64(7)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R8_7:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(7)) / s64(6)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R2_1:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(2)) / s64(3)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R1_1:
+        Sx = ((((s64(result) * s64(REGS.IR1)) * s64(7)) / s64(6)) + s64(REGS.OFX));
+        break;
+
+      case DisplayAspectRatio::R4_3:
+      case DisplayAspectRatio::PAR1_1:
+      default:
+        Sx = (s64(result) * s64(REGS.IR1) + s64(REGS.OFX));
+        break;
+    }
+  }
+  else
+  {
+    Sx = (s64(result) * s64(REGS.IR1) + s64(REGS.OFX));
+  }
+
   const s64 Sy = s64(result) * s64(REGS.IR2) + s64(REGS.OFY);
   CheckMACOverflow<0>(Sx);
   CheckMACOverflow<0>(Sy);
@@ -654,7 +696,53 @@ static void RTPS(const s16 V[3], u8 shift, bool lm, bool last)
     const float precise_h_div_sz = float(REGS.H) / precise_z;
     const float fofx = float(REGS.OFX) / float(1 << 16);
     const float fofy = float(REGS.OFY) / float(1 << 16);
-    float precise_x = fofx + (precise_ir1 * precise_h_div_sz) * ((g_settings.gpu_widescreen_hack) ? 0.75f : 1.00f);
+    float precise_x;
+    if (g_settings.gpu_widescreen_hack)
+    {
+      precise_x = precise_ir1 * precise_h_div_sz;
+      const DisplayAspectRatio ar = g_settings.display_aspect_ratio;
+      switch (ar)
+      {
+        case DisplayAspectRatio::R16_9:
+          precise_x = (precise_x * 3.0f) / 4.0f;
+          break;
+
+        case DisplayAspectRatio::R16_10:
+          precise_x = (precise_x * 5.0f) / 6.0f;
+          break;
+
+        case DisplayAspectRatio::R19_9:
+          precise_x = (precise_x * 12.0f) / 19.0f;
+          break;
+
+        case DisplayAspectRatio::R21_9:
+          precise_x = (precise_x * 4.0f) / 7.0f;
+          break;
+
+        case DisplayAspectRatio::R8_7:
+          precise_x = (precise_x * 7.0f) / 6.0f;
+          break;
+
+        case DisplayAspectRatio::R2_1:
+          precise_x = (precise_x * 2.0f) / 3.0f;
+          break;
+
+        case DisplayAspectRatio::R1_1:
+          precise_x = (precise_x * 7.0f) / 6.0f;
+          break;
+
+        case DisplayAspectRatio::R4_3:
+        case DisplayAspectRatio::PAR1_1:
+        default:
+          break;
+      }
+      precise_x += fofx;
+    }
+    else
+    {
+      precise_x = fofx + (precise_ir1 * precise_h_div_sz);
+    }
+
     float precise_y = fofy + (precise_ir2 * precise_h_div_sz);
 
     precise_x = std::clamp<float>(precise_x, -1024.0f, 1023.0f);

src/duckstation-libretro/libretro_host_interface.cpp

@@ -624,8 +624,8 @@ static std::array<retro_core_option_definition, 42> s_option_definitions = {{
    "Nearest"},
   {"duckstation_GPU.WidescreenHack",
    "Widescreen Hack",
-   "Increases the field of view from 4:3 to 16:9 in 3D games. For 2D games, or games which use pre-rendered "
+   "Increases the field of view from 4:3 to the chosen display aspect ratio in 3D games. For 2D games, or games which "
-   "backgrounds, this enhancement will not work as expected.",
+   "use pre-rendered backgrounds, this enhancement will not work as expected.",
    {{"true", "Enabled"}, {"false", "Disabled"}},
    "false"},
   {"duckstation_GPU.PGXPEnable",

src/duckstation-qt/enhancementsettingswidget.cpp

@@ -20,9 +20,9 @@ EnhancementSettingsWidget::EnhancementSettingsWidget(QtHostInterface* host_inter
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.force43For24Bit, "Display", "Force4_3For24Bit");
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.chromaSmoothingFor24Bit, "GPU",
                                                "ChromaSmoothing24Bit");
-  SettingWidgetBinder::BindWidgetToEnumSetting(
+  SettingWidgetBinder::BindWidgetToEnumSetting(m_host_interface, m_ui.textureFiltering, "GPU", "TextureFilter",
-    m_host_interface, m_ui.textureFiltering, "GPU", "TextureFilter", &Settings::ParseTextureFilterName,
+                                               &Settings::ParseTextureFilterName, &Settings::GetTextureFilterName,
-    &Settings::GetTextureFilterName, Settings::DEFAULT_GPU_TEXTURE_FILTER);
+                                               Settings::DEFAULT_GPU_TEXTURE_FILTER);
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.widescreenHack, "GPU", "WidescreenHack");
 
   SettingWidgetBinder::BindWidgetToBoolSetting(m_host_interface, m_ui.pgxpEnable, "GPU", "PGXPEnable", false);
@@ -88,9 +88,9 @@ EnhancementSettingsWidget::EnhancementSettingsWidget(QtHostInterface* host_inter
   dialog->registerWidgetHelp(
     m_ui.widescreenHack, tr("Widescreen Hack"), tr("Unchecked"),
     tr("Scales vertex positions in screen-space to a widescreen aspect ratio, essentially "
-       "increasing the field of view from 4:3 to 16:9 in 3D games. <br>For 2D games, or games which "
+       "increasing the field of view from 4:3 to the chosen display aspect ratio in 3D games. <br>For 2D games, or "
-       "use pre-rendered backgrounds, this enhancement will not work as expected. <br><b><u>May not be compatible with "
+       "games which use pre-rendered backgrounds, this enhancement will not work as expected. <br><b><u>May not be "
-       "all games.</u></b>"));
+       "compatible with all games.</u></b>"));
   dialog->registerWidgetHelp(
     m_ui.pgxpEnable, tr("Geometry Correction"), tr("Unchecked"),
     tr("Reduces \"wobbly\" polygons and \"warping\" textures that are common in PS1 games. <br>Only "

src/duckstation-qt/enhancementsettingswidget.ui

@@ -69,7 +69,7 @@
       <item row="5" column="0" colspan="2">
        <widget class="QCheckBox" name="widescreenHack">
         <property name="text">
-         <string>Widescreen Hack (render 3D in 16:9)</string>
+         <string>Widescreen Hack (render 3D in display aspect ratio)</string>
         </property>
        </widget>
       </item>