HDR: add menu brightness setting, remove MaxNits, refactor HDR UBO

Repurpose the old max_nits/Peak Luminance setting as a menu brightness
control. When compositing the SDR menu/overlay into the HDR backbuffer,
the driver temporarily overrides paper_white_nits with the new menu_nits
value so the existing shader handles brightness correctly.

- Rename set_hdr_max_nits -> set_hdr_menu_nits across all drivers
- Remove MaxNits from slang reflection and internal shader UBOs
- InverseTonemap/Tonemap now take explicit arguments (no UBO dependency)
- Internal shaders use BrightnessNits consistently for scRGB scaling
- Menu composite path: paper_white_nits = menu_nits during draw
- New setting in Settings > User Interface > Appearance (HDR only)
- Remove old Peak Luminance translations from locale files
- Fix HDR Brightness format string (whole number, no decimal/suffix)
- Default 200 nits, range 40-1000

Author: MajorPainTheCactus

config.def.h

@@ -503,8 +503,8 @@
 /* HDR output mode: 0 = off, 1 = HDR10, 2 = scRGB */
 #define DEFAULT_VIDEO_HDR_MODE 0
 
-/* The maximum nunmber of nits the actual display can show - needs to be calibrated */
-#define DEFAULT_VIDEO_HDR_MAX_NITS 1000.0f
+/* Brightness of the SDR menu/overlay when composited into the HDR backbuffer */
+#define DEFAULT_MENU_HDR_BRIGHTNESS_NITS 200.0f
 
 /* The number of nits that paper white is at */
 #define DEFAULT_VIDEO_HDR_PAPER_WHITE_NITS 200.0f

configuration.c

@@ -2384,7 +2384,7 @@ static struct config_float_setting *populate_settings_float(
    SETTING_FLOAT("video_message_pos_y",          &settings->floats.video_msg_pos_y, true, DEFAULT_MESSAGE_POS_OFFSET_Y, false);
    SETTING_FLOAT("video_font_size",              &settings->floats.video_font_size, true, DEFAULT_FONT_SIZE, false);
    SETTING_FLOAT("video_msg_bgcolor_opacity",    &settings->floats.video_msg_bgcolor_opacity, true, DEFAULT_MESSAGE_BGCOLOR_OPACITY, false);
-   SETTING_FLOAT("video_hdr_max_nits",           &settings->floats.video_hdr_max_nits, true, DEFAULT_VIDEO_HDR_MAX_NITS, false);
+   SETTING_FLOAT("video_hdr_menu_nits",           &settings->floats.video_hdr_menu_nits, true, DEFAULT_MENU_HDR_BRIGHTNESS_NITS, false);
    SETTING_FLOAT("video_hdr_paper_white_nits",   &settings->floats.video_hdr_paper_white_nits, true, DEFAULT_VIDEO_HDR_PAPER_WHITE_NITS, false);
 
    SETTING_FLOAT("input_axis_threshold",         &settings->floats.input_axis_threshold,     true, DEFAULT_AXIS_THRESHOLD, false);

configuration.h

@@ -429,7 +429,7 @@ typedef struct settings
       float video_msg_color_g;
       float video_msg_color_b;
       float video_msg_bgcolor_opacity;
-      float video_hdr_max_nits;
+      float video_hdr_menu_nits;
       float video_hdr_paper_white_nits;
 
       float menu_scale_factor;

gfx/common/dxgi_common.h

@@ -35,7 +35,6 @@ typedef struct ALIGN(16)
       float height;
    } output_size;
    float             paper_white_nits;    /* 200.0f  */
-   float             max_nits;            /* 1000.0f */
    unsigned          subpixel_layout;     /* 0       */
    float             scanlines;           /* 1.0f    */
    unsigned          expand_gamut;        /* 0       */

gfx/drivers/caca_gfx.c

@@ -416,7 +416,7 @@ static const video_poke_interface_t caca_poke_interface = {
    NULL, /* get_current_shader */
    NULL, /* get_current_software_framebuffer */
    NULL, /* get_hw_render_interface */
-   NULL, /* set_hdr_max_nits */
+   NULL, /* set_hdr_menu_nits */
    NULL, /* set_hdr_paper_white_nits */
    NULL, /* set_hdr_expand_gamut */
    NULL, /* set_hdr_scanlines */

gfx/drivers/ctr_gfx.c

@@ -2986,7 +2986,7 @@ static const video_poke_interface_t ctr_poke_interface = {
    NULL, /* get_current_shader */
    NULL, /* get_current_software_framebuffer */
    NULL, /* get_hw_render_interface */
-   NULL, /* set_hdr_max_nits */
+   NULL, /* set_hdr_menu_nits */
    NULL, /* set_hdr_paper_white_nits */
    NULL, /* set_hdr_expand_gamut */
    NULL, /* set_hdr_scanlines */

gfx/drivers/d3d10.c

@@ -3268,7 +3268,7 @@ static const video_poke_interface_t d3d10_poke_interface = {
 #else
    NULL, /* get_hw_render_interface */
 #endif
-   NULL, /* set_hdr_max_nits */
+   NULL, /* set_hdr_menu_nits */
    NULL, /* set_hdr_paper_white_nits */
    NULL, /* set_hdr_expand_gamut */
    NULL, /* set_hdr_scanlines */

gfx/drivers/d3d11.c

@@ -350,6 +350,7 @@ typedef struct
    {
       dxgi_hdr_uniform_t               ubo_values;
       D3D11Buffer                      ubo;
+      float                            menu_nits;
       float                            max_output_nits;
       float                            min_output_nits;
       float                            max_cll;
@@ -411,7 +412,6 @@ typedef struct
 #ifdef HAVE_DXGI_HDR
       unsigned                   hdr_mode;
       float                      paper_white_nits;
-      float                      max_nits;
       unsigned                   expand_gamut;
       float                      scanlines;
       unsigned                   subpixel_layout;
@@ -1576,13 +1576,12 @@ static void d3d11_render_overlay(d3d11_video_t *d3d11)
 #endif
 
 #ifdef HAVE_DXGI_HDR
-static void d3d11_set_hdr_max_nits(void *data, float max_nits)
+static void d3d11_set_hdr_menu_nits(void *data, float menu_nits)
 {
    D3D11_MAPPED_SUBRESOURCE mapped_ubo;
    d3d11_video_t* d3d11                   = (d3d11_video_t*)data;
 
-   d3d11->hdr.max_output_nits             = max_nits;
-   d3d11->hdr.ubo_values.max_nits         = max_nits;
+   d3d11->hdr.menu_nits        = menu_nits;
 
    d3d11->context->lpVtbl->Map(
          d3d11->context, (D3D11Resource)d3d11->hdr.ubo, 0, D3D11_MAP_WRITE_NO_OVERWRITE, 0, &mapped_ubo);
@@ -1591,20 +1590,6 @@ static void d3d11_set_hdr_max_nits(void *data, float max_nits)
       *ubo                    = d3d11->hdr.ubo_values;
    }
    d3d11->context->lpVtbl->Unmap(d3d11->context, (D3D11Resource)d3d11->hdr.ubo, 0);
-
-   /* Do NOT update display HDR metadata here.  max_nits is an internal
-    * shader parameter (InverseTonemap target), not the actual mastering
-    * display luminance.  Sending it as MaxMasteringLuminance causes the
-    * display's tone mapper to switch modes every time the user moves the
-    * slider, producing color shifts and delays. */
-
-   if(d3d11->shader_preset)
-   {
-      for (unsigned i = 0; i < d3d11->shader_preset->passes; i++)
-      {
-         d3d11->pass[i].max_nits     = max_nits;
-      }
-   }
 }
 
 static void d3d11_set_hdr_paper_white_nits(void* data, float paper_white_nits)
@@ -1989,7 +1974,6 @@ static bool d3d11_gfx_set_shader(void* data, enum rarch_shader_type type, const
 #ifdef HAVE_DXGI_HDR
             &d3d11->pass[i].hdr_mode,        /* HDRMode */
             &d3d11->pass[i].paper_white_nits,/* PaperWhiteNits */
-            &d3d11->pass[i].max_nits,        /* MaxNits */
             &d3d11->pass[i].scanlines,       /* Scanlines */
             &d3d11->pass[i].subpixel_layout, /* SubpixelLayout */
             &d3d11->pass[i].expand_gamut,    /* ExpandGamut */
@@ -2632,7 +2616,7 @@ static void *d3d11_gfx_init(const video_info_t* video,
    DXGICreateFactory1(&d3d11->factory);
 #endif
 #ifdef HAVE_DXGI_HDR
-   d3d11->hdr.max_output_nits             = settings->floats.video_hdr_max_nits;
+   d3d11->hdr.max_output_nits             = 1000.0f;
    d3d11->hdr.min_output_nits             = 0.001f;
    d3d11->hdr.max_cll                     = 0.0f;
    d3d11->hdr.max_fall                    = 0.0f;
@@ -2738,8 +2722,8 @@ static void *d3d11_gfx_init(const video_info_t* video,
       d3d11->hdr.ubo_values.source_size.height  = 0.0f;
       d3d11->hdr.ubo_values.output_size.width   = d3d11->frame.output_size.x;
       d3d11->hdr.ubo_values.output_size.height  = d3d11->frame.output_size.y;
-      d3d11->hdr.ubo_values.max_nits         =
-         settings->floats.video_hdr_max_nits;
+      d3d11->hdr.menu_nits        =
+         settings->floats.video_hdr_menu_nits;
       d3d11->hdr.ubo_values.paper_white_nits =
          settings->floats.video_hdr_paper_white_nits;
       d3d11->hdr.ubo_values.scanlines    =
@@ -3688,7 +3672,6 @@ static bool d3d11_gfx_frame(
             if (d3d11->flags & D3D11_ST_FLAG_HDR_ENABLE)
             {
                d3d11->pass[i].paper_white_nits  = settings->floats.video_hdr_paper_white_nits;
-               d3d11->pass[i].max_nits          = settings->floats.video_hdr_max_nits;
                d3d11->pass[i].scanlines         = settings->bools.video_hdr_scanlines ? 1.0f : 0.0f;
                d3d11->pass[i].subpixel_layout   = settings->uints.video_hdr_subpixel_layout;
                d3d11->pass[i].expand_gamut      = settings->uints.video_hdr_expand_gamut;
@@ -4171,9 +4154,13 @@ static bool d3d11_gfx_frame(
          const float    prev_inverse_tonemap       = d3d11->hdr.ubo_values.inverse_tonemap;
          const float    prev_hdr10                 = d3d11->hdr.ubo_values.hdr10;
          const unsigned prev_hdr_mode              = d3d11->hdr.ubo_values.hdr_mode;
+         const float    prev_paper_white_nits      = d3d11->hdr.ubo_values.paper_white_nits;
 
          d3d11->hdr.ubo_values.scanlines           = 0.0f;
 
+         /* Menu/overlay composite: use menu_nits for SDR menu brightness */
+         d3d11->hdr.ubo_values.paper_white_nits    = d3d11->hdr.menu_nits;
+
          if (video_info->hdr_mode == 2) /* scRGB: menu source is SDR */
          {
             d3d11->hdr.ubo_values.inverse_tonemap  = 0.0f;
@@ -4203,6 +4190,7 @@ static bool d3d11_gfx_frame(
          d3d11->hdr.ubo_values.inverse_tonemap  = prev_inverse_tonemap;
          d3d11->hdr.ubo_values.hdr10            = prev_hdr10;
          d3d11->hdr.ubo_values.hdr_mode         = prev_hdr_mode;
+         d3d11->hdr.ubo_values.paper_white_nits = prev_paper_white_nits;
       }
 
       context->lpVtbl->VSSetConstantBuffers(context, 0, 1, &d3d11->hdr.ubo);
@@ -4698,13 +4686,13 @@ static const video_poke_interface_t d3d11_poke_interface = {
    NULL, /* get_current_software_framebuffer */
    d3d11_get_hw_render_interface,
 #ifdef HAVE_DXGI_HDR
-   d3d11_set_hdr_max_nits,
+   d3d11_set_hdr_menu_nits,
    d3d11_set_hdr_paper_white_nits,
    d3d11_set_hdr_expand_gamut,
    d3d11_set_hdr_scanlines,
    d3d11_set_hdr_subpixel_layout
 #else
-   NULL, /* set_hdr_max_nits */
+   NULL, /* set_hdr_menu_nits */
    NULL, /* set_hdr_paper_white_nits */
    NULL, /* set_hdr_expand_gamut */
    NULL, /* set_hdr_scanlines */

gfx/drivers/d3d12.c

@@ -340,6 +340,7 @@ typedef struct
       D3D12_CONSTANT_BUFFER_VIEW_DESC  ubo_view;
       D3D12Resource                    ubo_post;
       D3D12_CONSTANT_BUFFER_VIEW_DESC  ubo_post_view;
+      float                            menu_nits;
       float                            max_output_nits;
       float                            min_output_nits;
       float                            max_cll;
@@ -406,7 +407,6 @@ typedef struct
 #ifdef HAVE_DXGI_HDR
       unsigned                        hdr_mode;
       float                           paper_white_nits;
-      float                           max_nits;
       float                           scanlines;
       unsigned                        subpixel_layout;
       unsigned                        expand_gamut;
@@ -1885,25 +1885,10 @@ static void d3d12_render_overlay(d3d12_video_t *d3d12)
 #endif
 
 #ifdef HAVE_DXGI_HDR
-static void d3d12_set_hdr_max_nits(void* data, float max_nits)
+static void d3d12_set_hdr_menu_nits(void* data, float menu_nits)
 {
    d3d12_video_t *d3d12                   = (d3d12_video_t*)data;
-   d3d12->hdr.max_output_nits             = max_nits;
-   d3d12->hdr.ubo_values.max_nits         = max_nits;
-
-   /* Do NOT update display HDR metadata here.  max_nits is an internal
-    * shader parameter (InverseTonemap target), not the actual mastering
-    * display luminance.  Sending it as MaxMasteringLuminance causes the
-    * display's tone mapper to switch modes every time the user moves the
-    * slider, producing color shifts and delays. */
-
-   if(d3d12->shader_preset)
-   {
-      for (unsigned i = 0; i < d3d12->shader_preset->passes; i++)
-      {
-         d3d12->pass[i].max_nits     = max_nits;
-      }
-   }
+   d3d12->hdr.menu_nits        = menu_nits;
 }
 
 static void d3d12_set_hdr_paper_white_nits(void* data, float paper_white_nits)
@@ -2270,7 +2255,6 @@ static bool d3d12_gfx_set_shader(void* data, enum rarch_shader_type type, const
 #ifdef HAVE_DXGI_HDR
             &d3d12->pass[i].hdr_mode,       /* HDRMode */
             &d3d12->pass[i].paper_white_nits,/* PaperWhiteNits */
-            &d3d12->pass[i].max_nits,        /* MaxNits */
             &d3d12->pass[i].scanlines,       /* Scanlines */
             &d3d12->pass[i].subpixel_layout, /* SubpixelLayout */
             &d3d12->pass[i].expand_gamut,    /* ExpandGamut */
@@ -3592,7 +3576,7 @@ static void *d3d12_gfx_init(const video_info_t* video,
       d3d12->flags                       |=  D3D12_ST_FLAG_HDR_ENABLE;
    else
       d3d12->flags                       &= ~D3D12_ST_FLAG_HDR_ENABLE;
-   d3d12->hdr.max_output_nits             = settings->floats.video_hdr_max_nits;
+   d3d12->hdr.max_output_nits             = 1000.0f;
    d3d12->hdr.min_output_nits             = 0.001f;
    d3d12->hdr.max_cll                     = 0.0f;
    d3d12->hdr.max_fall                    = 0.0f;
@@ -3678,7 +3662,7 @@ static void *d3d12_gfx_init(const video_info_t* video,
          d3d12_create_buffer(d3d12->device, d3d12->hdr.ubo_post_view.SizeInBytes, &d3d12->hdr.ubo_post);
 
    d3d12->hdr.ubo_values.mvp                 = d3d12->mvp_no_rot;
-   d3d12->hdr.ubo_values.max_nits            = settings->floats.video_hdr_max_nits;
+   d3d12->hdr.menu_nits           = settings->floats.video_hdr_menu_nits;
    d3d12->hdr.ubo_values.paper_white_nits    = settings->floats.video_hdr_paper_white_nits;
 
    d3d12->hdr.ubo_values.source_size.width   = 0.0f;
@@ -4429,7 +4413,6 @@ static bool d3d12_gfx_frame(
          if(d3d12->flags & D3D12_ST_FLAG_HDR_ENABLE)
          {
             d3d12->pass[i].paper_white_nits     = settings->floats.video_hdr_paper_white_nits;
-            d3d12->pass[i].max_nits             = settings->floats.video_hdr_max_nits;
             d3d12->pass[i].scanlines            = settings->bools.video_hdr_scanlines ? 1.0f : 0.0f;
             d3d12->pass[i].subpixel_layout      = settings->uints.video_hdr_subpixel_layout;
             d3d12->pass[i].expand_gamut         = settings->uints.video_hdr_expand_gamut;
@@ -5029,9 +5012,13 @@ static bool d3d12_gfx_frame(
          const float    prev_inverse_tonemap       = d3d12->hdr.ubo_values.inverse_tonemap;
          const float    prev_hdr10                 = d3d12->hdr.ubo_values.hdr10;
          const unsigned prev_hdr_mode              = d3d12->hdr.ubo_values.hdr_mode;
+         const float    prev_paper_white_nits      = d3d12->hdr.ubo_values.paper_white_nits;
 
          d3d12->hdr.ubo_values.scanlines           = 0.0f;
 
+         /* Menu/overlay composite: use menu_nits for SDR menu brightness */
+         d3d12->hdr.ubo_values.paper_white_nits    = d3d12->hdr.menu_nits;
+
          if (video_info->hdr_mode == 2) /* scRGB: menu source is SDR */
          {
             d3d12->hdr.ubo_values.inverse_tonemap  = 0.0f;
@@ -5063,6 +5050,7 @@ static bool d3d12_gfx_frame(
          d3d12->hdr.ubo_values.inverse_tonemap     = prev_inverse_tonemap;
          d3d12->hdr.ubo_values.hdr10               = prev_hdr10;
          d3d12->hdr.ubo_values.hdr_mode            = prev_hdr_mode;
+         d3d12->hdr.ubo_values.paper_white_nits    = prev_paper_white_nits;
       }
 
       cmd->lpVtbl->IASetVertexBuffers(cmd, 0, 1, &d3d12->frame.vbo_view);
@@ -5462,13 +5450,13 @@ static const video_poke_interface_t d3d12_poke_interface = {
    NULL, /* get_current_software_framebuffer */
    d3d12_get_hw_render_interface,
 #ifdef HAVE_DXGI_HDR
-   d3d12_set_hdr_max_nits,
+   d3d12_set_hdr_menu_nits,
    d3d12_set_hdr_paper_white_nits,
    d3d12_set_hdr_expand_gamut,
    d3d12_set_hdr_scanlines,
    d3d12_set_hdr_subpixel_layout
 #else
-   NULL, /* set_hdr_max_nits */
+   NULL, /* set_hdr_menu_nits */
    NULL, /* set_hdr_paper_white_nits */
    NULL, /* set_hdr_expand_gamut */
    NULL, /* set_hdr_scanlines */

gfx/drivers/d3d8.c

@@ -2172,7 +2172,7 @@ static const video_poke_interface_t d3d_poke_interface = {
    NULL, /* get_current_shader */
    NULL, /* get_current_software_framebuffer */
    NULL, /* get_hw_render_interface */
-   NULL, /* set_hdr_max_nits */
+   NULL, /* set_hdr_menu_nits */
    NULL, /* set_hdr_paper_white_nits */
    NULL, /* set_hdr_expand_gamut */
    NULL, /* set_hdr_scanlines */