gfx: rename {fpga,gdi}_t::video_{width,height,pitch,bits} to frame_*

Same rename as gfx/gl1 in d654940, applied to the FPGA and GDI
drivers for consistency.  The four `video_*` fields on each driver
struct hold the libretro core's emulated frame size — assigned from
`video->width` / `video->height` at init and updated from
`frame_width` / `frame_height` per-call — not the window or
backbuffer size.  Both drivers already have separate fields for the
distinct concepts they track:

  fpga_t:  menu_width / menu_height / menu_pitch / menu_bits
           (the menu surface, sibling to the core frame group)

  gdi_t:   screen_width / screen_height (actual surface size)
           full_width / full_height     (window size last published
                                         via video_driver_set_size)
           bmp_width / bmp_height       (DDB's own size)
           menu_width / menu_height / menu_pitch / menu_bits

For gdi, the semantic mismatch was already partially documented in
two defensive comments in gdi_defines.h (lines 114-116 and 119-124
before this commit) and one in gdi_gfx.c (around line 2853).
Renaming the fields lets those comments shrink: the field name now
says what it is, so the explanations no longer need to warn the
reader off the wrong reading.

Rename in both drivers:

  video_width  -> frame_width
  video_height -> frame_height
  video_pitch  -> frame_pitch
  video_bits   -> frame_bits

fpga_t is file-private (declared at the top of fpga_gfx.c with no
header counterpart): the rename is contained to that one file, 11
reference sites plus the four declarations.

gdi_t lives in the shared header gfx/common/gdi_defines.h, used by
both gfx/drivers/gdi_gfx.c and gfx/common/win32_common.c (the
shared WM_PAINT body for the three GDI window procs).  20 reference
sites updated in gdi_gfx.c, 3 in win32_common.c, plus the four
declarations and three comment rewrites.  No callers outside these
three files (verified by grep across the source tree).

Same risk profile as gl1: pure rename, no behavior change, no new
code paths.  Causes future cross-driver copy-paste from gl2 / gl3
to fail at compile time (`fpga->video_width` / `gdi->video_width`
no longer exist) instead of silently producing a different result.

Verified that no stale `fpga->video_(...)` or `gdi->video_(...)`
field references remain, and that the renamed fields compile clean
at -std=c89 -pedantic against stub harnesses.

gfx/common/gdi_defines.h

@@ -107,19 +107,18 @@ typedef struct gdi
    unsigned  scratch_rgui_w;
    unsigned  scratch_rgui_h;
 
-   unsigned video_width;
-   unsigned video_height;
+   unsigned frame_width;
+   unsigned frame_height;
    unsigned screen_width;
    unsigned screen_height;
    /* Surface (window) size last published via video_driver_set_size,
-    * tracked here so gdi_alive can read it without locking.  Distinct
-    * from video_width / video_height which is the core's frame size. */
+    * tracked here so gdi_alive can read it without locking. */
    unsigned full_width;
    unsigned full_height;
-   /* Actual size of gdi->bmp (the DDB).  Separate from video_width
+   /* Actual size of gdi->bmp (the DDB).  Separate from frame_width
     * because when RGUI is active we draw the menu (a different size
     * than the core) into bmp; without a dedicated tracker, the
-    * comparison against video_width would trigger a destructive
+    * comparison against frame_width would trigger a destructive
     * DeleteObject + CreateCompatibleBitmap on every frame, racing
     * with WM_PAINT and producing visible flicker. */
    unsigned bmp_width;
@@ -128,8 +127,8 @@ typedef struct gdi
    unsigned menu_width;
    unsigned menu_height;
    unsigned menu_pitch;
-   unsigned video_pitch;
-   unsigned video_bits;
+   unsigned frame_pitch;
+   unsigned frame_bits;
    unsigned menu_bits;
    int win_major;
    int win_minor;

gfx/common/win32_common.c

@@ -1345,16 +1345,16 @@ static LRESULT wnd_proc_wm_gdi_create(HWND hwnd)
  * outside the rect with black to produce letterbox / pillarbox
  * bars.  Reads bmp_width / bmp_height for the source rect (the
  * DDB's actual size); when RGUI is alive bmp holds the menu image
- * at the menu's resolution while gdi->video_width still tracks
- * the core, so video_width is only the fallback. */
+ * at the menu's resolution while gdi->frame_width still tracks
+ * the core, so frame_width is only the fallback. */
 static void wnd_proc_gdi_paint(gdi_t *gdi)
 {
    int       vp_x   = gdi->vp.x;
    int       vp_y   = gdi->vp.y;
    unsigned  vp_w   = gdi->vp.width  ? gdi->vp.width  : gdi->screen_width;
    unsigned  vp_h   = gdi->vp.height ? gdi->vp.height : gdi->screen_height;
-   unsigned  src_w  = gdi->bmp_width  ? gdi->bmp_width  : gdi->video_width;
-   unsigned  src_h  = gdi->bmp_height ? gdi->bmp_height : gdi->video_height;
+   unsigned  src_w  = gdi->bmp_width  ? gdi->bmp_width  : gdi->frame_width;
+   unsigned  src_h  = gdi->bmp_height ? gdi->bmp_height : gdi->frame_height;
 
    /* Letterbox / pillarbox bars: paint the four areas outside the
     * viewport rect black before the StretchBlt.  We do this even

gfx/drivers/fpga_gfx.c

@@ -57,10 +57,10 @@ typedef struct fpga
    unsigned menu_width;
    unsigned menu_height;
    unsigned menu_pitch;
-   unsigned video_width;
-   unsigned video_height;
-   unsigned video_pitch;
-   unsigned video_bits;
+   unsigned frame_width;
+   unsigned frame_height;
+   unsigned frame_pitch;
+   unsigned frame_bits;
    unsigned menu_bits;
    bool rgb32;
 } fpga_t;
@@ -138,16 +138,16 @@ static void *fpga_init(const video_info_t *video,
    *input                               = NULL;
    *input_data                          = NULL;
 
-   fpga->video_width                    = video->width;
-   fpga->video_height                   = video->height;
+   fpga->frame_width                    = video->width;
+   fpga->frame_height                   = video->height;
    fpga->rgb32                          = video->rgb32;
 
-   fpga->video_bits                     = video->rgb32 ? 32 : 16;
+   fpga->frame_bits                     = video->rgb32 ? 32 : 16;
 
    if (video->rgb32)
-      fpga->video_pitch = video->width * 4;
+      fpga->frame_pitch = video->width * 4;
    else
-      fpga->video_pitch = video->width * 2;
+      fpga->frame_pitch = video->width * 2;
 
    fpga_create(fpga);
 
@@ -168,7 +168,7 @@ static bool fpga_frame(void *data, const void *frame,
    unsigned height           = 0;
    bool draw                 = true;
    fpga_t *fpga              = (fpga_t*)data;
-   unsigned bits             = fpga->video_bits;
+   unsigned bits             = fpga->frame_bits;
 #ifdef HAVE_MENU
    bool menu_is_alive = (video_info->menu_st_flags & MENU_ST_FLAG_ALIVE) ? true : false;
 #endif
@@ -180,15 +180,15 @@ static bool fpga_frame(void *data, const void *frame,
    menu_driver_frame(menu_is_alive, video_info);
 #endif
 
-   if (     (fpga->video_width  != frame_width)
-         || (fpga->video_height != frame_height)
-         || (fpga->video_pitch  != pitch))
+   if (     (fpga->frame_width  != frame_width)
+         || (fpga->frame_height != frame_height)
+         || (fpga->frame_pitch  != pitch))
    {
       if (frame_width > 4 && frame_height > 4)
       {
-         fpga->video_width = frame_width;
-         fpga->video_height = frame_height;
-         fpga->video_pitch = pitch;
+         fpga->frame_width = frame_width;
+         fpga->frame_height = frame_height;
+         fpga->frame_pitch = pitch;
       }
    }
 
@@ -204,9 +204,9 @@ static bool fpga_frame(void *data, const void *frame,
    else
 #endif
    {
-      width         = fpga->video_width;
-      height        = fpga->video_height;
-      pitch         = fpga->video_pitch;
+      width         = fpga->frame_width;
+      height        = fpga->frame_height;
+      pitch         = fpga->frame_pitch;
 
       if (frame_width == 4 && frame_height == 4 && (frame_width < width && frame_height < height))
          draw = false;

gfx/drivers/gdi_gfx.c

@@ -2171,8 +2171,8 @@ static void gdi_font_render_msg(
    else
    {
       dst_bmp = gdi->bmp;
-      width   = gdi->bmp_width  ? gdi->bmp_width  : gdi->video_width;
-      height  = gdi->bmp_height ? gdi->bmp_height : gdi->video_height;
+      width   = gdi->bmp_width  ? gdi->bmp_width  : gdi->frame_width;
+      height  = gdi->bmp_height ? gdi->bmp_height : gdi->frame_height;
    }
 
    if (!dst_bmp || !width || !height)
@@ -2474,16 +2474,16 @@ static void *gdi_init(const video_info_t *video,
    *input                               = NULL;
    *input_data                          = NULL;
 
-   gdi->video_width                     = video->width;
-   gdi->video_height                    = video->height;
+   gdi->frame_width                     = video->width;
+   gdi->frame_height                    = video->height;
    gdi->rgb32                           = video->rgb32;
 
-   gdi->video_bits                      = video->rgb32 ? 32 : 16;
+   gdi->frame_bits                      = video->rgb32 ? 32 : 16;
 
    if (video->rgb32)
-      gdi->video_pitch                  = video->width * 4;
+      gdi->frame_pitch                  = video->width * 4;
    else
-      gdi->video_pitch                  = video->width * 2;
+      gdi->frame_pitch                  = video->width * 2;
 
    /* Aspect-ratio handling.  Pulled from video_info_t at init the
     * same way d3d8/d3d9 do it; the user can override via the
@@ -2575,7 +2575,7 @@ static bool gdi_frame(void *data, const void *frame,
    unsigned height                  = 0;
    bool draw                        = true;
    gdi_t *gdi                       = (gdi_t*)data;
-   unsigned bits                    = gdi->video_bits;
+   unsigned bits                    = gdi->frame_bits;
    HWND hwnd                        = win32_get_window();
 #ifdef HAVE_MENU
    bool menu_is_alive               = (video_info->menu_st_flags & MENU_ST_FLAG_ALIVE)
@@ -2639,8 +2639,8 @@ static bool gdi_frame(void *data, const void *frame,
             gdi->winDC, frame_width, frame_height);
       gdi->bmp_width    = frame_width;
       gdi->bmp_height   = frame_height;
-      gdi->video_width  = frame_width;
-      gdi->video_height = frame_height;
+      gdi->frame_width  = frame_width;
+      gdi->frame_height = frame_height;
    }
 
    /* --- Step 2: figure out the on-screen surface size. */
@@ -2788,7 +2788,7 @@ static bool gdi_frame(void *data, const void *frame,
          && frame_height > 4)
    {
       gdi_upload_core_frame_to_menu(gdi, frame,
-            frame_width, frame_height, pitch, gdi->video_bits);
+            frame_width, frame_height, pitch, gdi->frame_bits);
    }
 #endif
 
@@ -2803,15 +2803,15 @@ static bool gdi_frame(void *data, const void *frame,
    /* --- Step 6: track core-frame size changes (needed for both the
     * RGUI-overlay path and the no-menu path).  We resize bmp here
     * if the core's announced dimensions changed. */
-   if (     (gdi->video_width  != frame_width)
-         || (gdi->video_height != frame_height)
-         || (gdi->video_pitch  != pitch))
+   if (     (gdi->frame_width  != frame_width)
+         || (gdi->frame_height != frame_height)
+         || (gdi->frame_pitch  != pitch))
    {
       if (frame_width > 4 && frame_height > 4)
       {
-         gdi->video_width  = frame_width;
-         gdi->video_height = frame_height;
-         gdi->video_pitch  = pitch;
+         gdi->frame_width  = frame_width;
+         gdi->frame_height = frame_height;
+         gdi->frame_pitch  = pitch;
       }
    }
 
@@ -2832,9 +2832,9 @@ static bool gdi_frame(void *data, const void *frame,
    else
 #endif
    {
-      width         = gdi->video_width;
-      height        = gdi->video_height;
-      pitch         = gdi->video_pitch;
+      width         = gdi->frame_width;
+      height        = gdi->frame_height;
+      pitch         = gdi->frame_pitch;
 
       if (  frame_width  == 4
          && frame_height == 4
@@ -2850,7 +2850,7 @@ static bool gdi_frame(void *data, const void *frame,
    /* --- Step 8: resize bmp if its current size doesn't match the
     * effective draw target size (width/height computed in Step 7).
     * We compare against bmp_width/bmp_height (the DDB's own size),
-    * NOT video_width — the latter holds the core's announced frame
+    * NOT frame_width — the latter holds the core's announced frame
     * size, which can legitimately differ from the menu's frame size
     * when RGUI is alive.  Conflating the two causes a destructive
     * recreate every frame as Steps 6 and 8 fight over the field. */