/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *  Copyright (C) 2016-2019 - Brad Parker
 *
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */
#include "gfx_display.h"

#include "video_coord_array.h"
#include "../configuration.h"
#include "../verbosity.h"

/* Standard reference DPI value, used when determining
 * DPI-aware scaling factors */
#define REFERENCE_DPI 96.0f

/* 'OZONE_SIDEBAR_WIDTH' must be kept in sync
 * with Ozone driver metrics */
#define OZONE_SIDEBAR_WIDTH 408

/* TODO/FIXME - global that gets referenced outside,
 * needs to be refactored */
uintptr_t gfx_display_white_texture;

static bool gfx_display_null_font_init_first(
      void **font_handle, void *video_data,
      const char *font_path, float font_size,
      bool is_threaded)
{
   font_data_t **handle = (font_data_t**)font_handle;
   if ((*handle = font_driver_init_first(video_data,
         font_path, font_size, true,
         is_threaded,
         FONT_DRIVER_RENDER_DONT_CARE)))
      return true;
   return false;
}

static const float *null_get_default_matrix(void)
{
   static float dummy[16] = {0.0f};
   return &dummy[0];
}

gfx_display_ctx_driver_t gfx_display_ctx_null = {
   NULL,                                     /* draw            */
   NULL,                                     /* draw_pipeline   */
   NULL,                                     /* blend_begin     */
   NULL,                                     /* blend_end       */
   NULL,                                     /* get_default_mvp */
   null_get_default_matrix,
   null_get_default_matrix,
   gfx_display_null_font_init_first,
   GFX_VIDEO_DRIVER_GENERIC,
   "null",
   false,
   NULL,
   NULL
};

/* Menu display drivers */
static gfx_display_ctx_driver_t *gfx_display_ctx_drivers[] = {
#ifdef HAVE_D3D8
   &gfx_display_ctx_d3d8,
#endif
#ifdef HAVE_D3D9
   &gfx_display_ctx_d3d9,
#endif
#ifdef HAVE_D3D10
   &gfx_display_ctx_d3d10,
#endif
#ifdef HAVE_D3D11
   &gfx_display_ctx_d3d11,
#endif
#ifdef HAVE_D3D12
   &gfx_display_ctx_d3d12,
#endif
#ifdef HAVE_OPENGL
   &gfx_display_ctx_gl,
#endif
#ifdef HAVE_OPENGL1
   &gfx_display_ctx_gl1,
#endif
#ifdef HAVE_OPENGL_CORE
   &gfx_display_ctx_gl_core,
#endif
#ifdef HAVE_VULKAN
   &gfx_display_ctx_vulkan,
#endif
#ifdef HAVE_METAL
   &gfx_display_ctx_metal,
#endif
#ifdef HAVE_VITA2D
   &gfx_display_ctx_vita2d,
#endif
#ifdef _3DS
   &gfx_display_ctx_ctr,
#endif
#ifdef WIIU
   &gfx_display_ctx_wiiu,
#endif
#if defined(_WIN32) && !defined(_XBOX) && !defined(__WINRT__)
#ifdef HAVE_GDI
   &gfx_display_ctx_gdi,
#endif
#endif
   &gfx_display_ctx_null,
   NULL,
};

float gfx_display_get_adjusted_scale(
      gfx_display_t *p_disp,
      float base_scale, float scale_factor, unsigned width)
{
   /* Apply user-set scaling factor */
   float adjusted_scale   = base_scale * scale_factor;
#ifdef HAVE_OZONE
   /* Ozone has a capped scale factor */
   if (p_disp->menu_driver_id == MENU_DRIVER_ID_OZONE)
   {
      float new_width    = (float)width * 0.3333333f;
      if (((float)OZONE_SIDEBAR_WIDTH * adjusted_scale)
            > new_width)
         adjusted_scale  = (new_width / (float)OZONE_SIDEBAR_WIDTH);
   }
#endif

   /* Ensure final scale is 'sane' */
   if (adjusted_scale <= 0.0001f)
      return 1.0f;
   return adjusted_scale;
}

/* Check if the current menu driver is compatible
 * with your video driver. */
static bool gfx_display_check_compatibility(
      enum gfx_display_driver_type type,
      bool video_is_threaded)
{
   const char *video_driver = video_driver_get_ident();

   switch (type)
   {
      case GFX_VIDEO_DRIVER_GENERIC:
         return true;
      case GFX_VIDEO_DRIVER_OPENGL:
         if (string_is_equal(video_driver, "gl"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_OPENGL1:
         if (string_is_equal(video_driver, "gl1"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_OPENGL_CORE:
         if (string_is_equal(video_driver, "glcore"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_VULKAN:
         if (string_is_equal(video_driver, "vulkan"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_METAL:
         if (string_is_equal(video_driver, "metal"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_DIRECT3D8:
         if (string_is_equal(video_driver, "d3d8"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_DIRECT3D9:
         if (string_is_equal(video_driver, "d3d9"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_DIRECT3D10:
         if (string_is_equal(video_driver, "d3d10"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_DIRECT3D11:
         if (string_is_equal(video_driver, "d3d11"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_DIRECT3D12:
         if (string_is_equal(video_driver, "d3d12"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_VITA2D:
         if (string_is_equal(video_driver, "vita2d"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_CTR:
         if (string_is_equal(video_driver, "ctr"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_WIIU:
         if (string_is_equal(video_driver, "gx2"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_GDI:
         if (string_is_equal(video_driver, "gdi"))
            return true;
         break;
      case GFX_VIDEO_DRIVER_SWITCH:
         if (string_is_equal(video_driver, "switch"))
            return true;
         break;
   }

   return false;
}

float gfx_display_get_dpi_scale_internal(
      unsigned width, unsigned height)
{
   float dpi;
   float diagonal_pixels;
   float pixel_scale;
   static unsigned last_width  = 0;
   static unsigned last_height = 0;
   static float scale          = 0.0f;
   static bool scale_cached    = false;
   gfx_ctx_metrics_t metrics;

   if (scale_cached &&
       (width == last_width) &&
       (height == last_height))
      return scale;

   /* Determine the diagonal 'size' of the display
    * (or window) in terms of pixels */
   diagonal_pixels = (float)sqrt(
         (double)((width * width) + (height * height)));

   /* TODO/FIXME: On Mac, calling video_context_driver_get_metrics()
    * here causes RetroArch to crash (EXC_BAD_ACCESS). This is
    * unfortunate, and needs to be fixed at the gfx context driver
    * level. Until this is done, all we can do is fallback to using
    * the old legacy 'magic number' scaling on Mac platforms. */
#if !defined(HAVE_COCOATOUCH) && (defined(HAVE_COCOA) || defined(HAVE_COCOA_METAL))
   if (true)
   {
      scale        = (diagonal_pixels / 6.5f) / 212.0f;
      scale_cached = true;
      last_width   = width;
      last_height  = height;
      return scale;
   }
#endif

   /* Get pixel scale relative to baseline 1080p display */
   pixel_scale = diagonal_pixels / DIAGONAL_PIXELS_1080P;

   /* Attempt to get display DPI */
   metrics.type  = DISPLAY_METRIC_DPI;
   metrics.value = &dpi;

   if (video_context_driver_get_metrics(&metrics) && (dpi > 0.0f))
   {
      float display_size;
      float dpi_scale;

#if defined(ANDROID) || defined(HAVE_COCOATOUCH)
      /* Android/iOS devices tell complete lies when
       * reporting DPI values. From the Android devices
       * I've had access to, the DPI is generally
       * overestimated by 17%. All we can do is apply
       * a blind correction factor... */
      dpi *= 0.83f;
#endif

      /* Note: If we are running in windowed mode, this
       * 'display size' is actually the window size - which
       * kinda makes a mess of everything. Since we cannot
       * get fullscreen resolution when running in windowed
       * mode, there is nothing we can do about this. So just
       * treat the window as a display, and hope for the best... */
      display_size = diagonal_pixels / dpi;
      dpi_scale    = dpi / REFERENCE_DPI;

      /* Note: We have tried leveraging every possible metric
       * (and numerous studies on TV/monitor/mobile device
       * usage habits) to determine an appropriate auto scaling
       * factor. *None of these 'smart'/technical methods work
       * consistently in the real world* - there is simply too
       * much variance.
       * So instead we have implemented a very fuzzy/loose
       * method which is crude as can be, but actually has
       * some semblance of usability... */

      if (display_size > 24.0f)
      {
         /* DPI scaling fails miserably when using large
          * displays. Having a UI element that's 1 inch high
          * on all screens might seem like a good idea - until
          * you realise that a HTPC user is probably sitting
          * several metres from their TV, which makes something
          * 1 inch high virtually invisible.
          * So we make some assumptions:
          * - Normal size displays <= 24 inches are probably
          *   PC monitors, with an eye-to-screen distance of
          *   1 arm length. Under these conditions, fixed size
          *   (DPI scaled) UI elements should be visible for most
          *   users
          * - Large displays > 24 inches start to encroach on
          *   TV territory. Once we start working with TVs, we
          *   have to consider users sitting on a couch - and
          *   in this situation, we fall back to the age-old
          *   standard of UI elements occupying a fixed fraction
          *   of the display size (i.e. just look at the menu of
          *   any console system for the past decade)
          * - 24 -> 32 inches is a grey area, where the display
          *   might be a monitor or a TV. Above 32 inches, a TV
          *   is almost a certainty. So we simply lerp between
          *   dpi scaling and pixel scaling as the display size
          *   increases from 24 to 32 */
         float fraction  = (display_size > 32.0f) ? 32.0f : display_size;
         fraction       -= 24.0f;
         fraction       /= (32.0f - 24.0f);

         scale           =   ((1.0f - fraction) * dpi_scale) 
                           + (fraction * pixel_scale);
      }
      else if (display_size < 12.0f)
      {
         /* DPI scaling also fails when using very small
          * displays - i.e. mobile devices (tablets/phones).
          * That 1 inch UI element is going to look pretty
          * dumb on a 5 inch screen in landscape orientation...
          * We're essentially in the opposite situation to the
          * TV case above, and it turns out that a similar
          * solution provides relief: as screen size reduces
          * from 12 inches to zero, we lerp from dpi scaling
          * to pixel scaling */
         float fraction = display_size / 12.0f;

         scale          =   ((1.0f - fraction) * pixel_scale) 
                          + (fraction * dpi_scale);
      }
      else
         scale          = dpi_scale;
   }
   /* If DPI retrieval is unsupported, all we can do
    * is use the raw pixel scale */
   else
      scale             = pixel_scale;

   scale_cached         = true;
   last_width           = width;
   last_height          = height;

   return scale;
}

float gfx_display_get_dpi_scale(
      gfx_display_t *p_disp,
      void *settings_data,
      unsigned width, unsigned height)
{
   static unsigned last_width                          = 0;
   static unsigned last_height                         = 0;
   static float scale                                  = 0.0f;
   static bool scale_cached                            = false;
   bool scale_updated                                  = false;
   static float last_menu_scale_factor                 = 0.0f;
   static enum menu_driver_id_type last_menu_driver_id = MENU_DRIVER_ID_UNKNOWN;
   static float adjusted_scale                         = 1.0f;
   settings_t *settings                                = (settings_t*)settings_data;
   float menu_scale_factor                             = settings->floats.menu_scale_factor;

   /* Scale is based on display metrics - these are a fixed
    * hardware property. To minimise performance overheads
    * we therefore only call video_context_driver_get_metrics()
    * on first run, or when the current video resolution changes */
   if (!scale_cached ||
       (width  != last_width) ||
       (height != last_height))
   {
      scale         = gfx_display_get_dpi_scale_internal(width, height);
      scale_cached  = true;
      scale_updated = true;
      last_width    = width;
      last_height   = height;
   }

   /* Adjusted scale calculation may also be slow, so
    * only update if something changes */
   if (scale_updated ||
       (menu_scale_factor != last_menu_scale_factor) ||
       (p_disp->menu_driver_id != last_menu_driver_id))
   {
      adjusted_scale         = gfx_display_get_adjusted_scale(
            p_disp,
            scale, menu_scale_factor, width);
      last_menu_scale_factor = menu_scale_factor;
      last_menu_driver_id    = p_disp->menu_driver_id;
   }

   return adjusted_scale;
}

/* Begin scissoring operation */
void gfx_display_scissor_begin(
      gfx_display_t *p_disp,
      void *userdata,
      unsigned video_width,
      unsigned video_height,
      int x, int y, unsigned width, unsigned height)
{
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;
   if (dispctx && dispctx->scissor_begin)
   {
      if (y < 0)
      {
         if (height < (unsigned)(-y))
            height = 0;
         else
            height += y;
         y = 0;
      }
      if (x < 0)
      {
         if (width < (unsigned)(-x))
            width = 0;
         else
            width += x;
         x = 0;
      }
      if (y >= (int)video_height)
      {
         height = 0;
         y = 0;
      }
      if (x >= (int)video_width)
      {
         width = 0;
         x = 0;
      }
      if ((y + height) > video_height)
         height = video_height - y;
      if ((x + width) > video_width)
         width = video_width - x;

      dispctx->scissor_begin(userdata,
            video_width, video_height,
            x, y, width, height);
   }
}

font_data_t *gfx_display_font_file(
      gfx_display_t *p_disp,
      char* fontpath, float menu_font_size, bool is_threaded)
{
   font_data_t            *font_data = NULL;
   float                  font_size  = menu_font_size;
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;

   if (!dispctx)
      return NULL;

   /* Font size must be at least 2, or font_init_first()
    * will generate a heap-buffer-overflow when using
    * many font drivers */
   if (font_size < 2.0f)
      font_size = 2.0f;

   if (!dispctx->font_init_first((void**)&font_data,
            video_driver_get_ptr(),
            fontpath, font_size, is_threaded))
      return NULL;

   return font_data;
}

void gfx_display_draw_bg(
      gfx_display_t *p_disp,
      gfx_display_ctx_draw_t *draw,
      void *userdata, bool add_opacity_to_wallpaper,
      float override_opacity)
{
   static struct video_coords coords;
   const float           *new_vertex = NULL;
   const float        *new_tex_coord = NULL;
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;
   if (!dispctx || !draw)
      return;

   if (draw->vertex)
      new_vertex                     = draw->vertex;
   else if (dispctx->get_default_vertices)
      new_vertex                     = dispctx->get_default_vertices();

   if (draw->tex_coord)
      new_tex_coord                  = draw->tex_coord;
   else if (dispctx->get_default_tex_coords)
      new_tex_coord                  = dispctx->get_default_tex_coords();

   coords.vertices                   = (unsigned)draw->vertex_count;
   coords.vertex                     = new_vertex;
   coords.tex_coord                  = new_tex_coord;
   coords.lut_tex_coord              = new_tex_coord;
   coords.color                      = (const float*)draw->color;

   draw->coords                      = &coords;
   draw->scale_factor                = 1.0f;
   draw->rotation                    = 0.0f;

   if (draw->texture)
      add_opacity_to_wallpaper       = true;
   else
      draw->texture                  = gfx_display_white_texture;

   if (add_opacity_to_wallpaper)
      gfx_display_set_alpha(draw->color, override_opacity);

   if (dispctx->get_default_mvp)
      draw->matrix_data = (math_matrix_4x4*)dispctx->get_default_mvp(
            userdata);
}

void gfx_display_draw_quad(
      gfx_display_t *p_disp,
      void *data,
      unsigned video_width,
      unsigned video_height,
      int x, int y, unsigned w, unsigned h,
      unsigned width, unsigned height,
      float *color)
{
   gfx_display_ctx_draw_t draw;
   struct video_coords coords;
   gfx_display_ctx_driver_t 
      *dispctx             = p_disp->dispctx;

   if (w == 0 || h == 0)
      return;
   if (!dispctx)
      return;

   coords.vertices      = 4;
   coords.vertex        = NULL;
   coords.tex_coord     = NULL;
   coords.lut_tex_coord = NULL;
   coords.color         = color;

   draw.x               = x;
   draw.y               = (int)height - y - (int)h;
   draw.width           = w;
   draw.height          = h;
   draw.coords          = &coords;
   draw.matrix_data     = NULL;
   draw.texture         = gfx_display_white_texture;
   draw.prim_type       = GFX_DISPLAY_PRIM_TRIANGLESTRIP;
   draw.pipeline_id     = 0;
   draw.scale_factor    = 1.0f;
   draw.rotation        = 0.0f;

   if (dispctx->blend_begin)
      dispctx->blend_begin(data);
   if (dispctx->draw)
      dispctx->draw(&draw, data, video_width, video_height);
   if (dispctx->blend_end)
      dispctx->blend_end(data);
}

void gfx_display_draw_polygon(
      gfx_display_t *p_disp,
      void *userdata,
      unsigned video_width,
      unsigned video_height,
      int x1, int y1,
      int x2, int y2,
      int x3, int y3,
      int x4, int y4,
      unsigned width, unsigned height,
      float *color)
{
   float vertex[8];
   gfx_display_ctx_draw_t draw;
   struct video_coords coords;
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;

   if (width == 0 || height == 0)
      return;
   if (!dispctx)
      return;

   vertex[0]             = x1 / (float)width;
   vertex[1]             = y1 / (float)height;
   vertex[2]             = x2 / (float)width;
   vertex[3]             = y2 / (float)height;
   vertex[4]             = x3 / (float)width;
   vertex[5]             = y3 / (float)height;
   vertex[6]             = x4 / (float)width;
   vertex[7]             = y4 / (float)height;

   coords.vertices       = 4;
   coords.vertex         = &vertex[0];
   coords.tex_coord      = NULL;
   coords.lut_tex_coord  = NULL;
   coords.color          = color;

   draw.x                = 0;
   draw.y                = 0;
   draw.width            = width;
   draw.height           = height;
   draw.coords           = &coords;
   draw.matrix_data      = NULL;
   draw.texture          = gfx_display_white_texture;
   draw.prim_type        = GFX_DISPLAY_PRIM_TRIANGLESTRIP;
   draw.pipeline_id      = 0;
   draw.scale_factor     = 1.0f;
   draw.rotation         = 0.0f;

   if (dispctx->blend_begin)
      dispctx->blend_begin(userdata);
   if (dispctx->draw)
      dispctx->draw(&draw, userdata, video_width, video_height);
   if (dispctx->blend_end)
      dispctx->blend_end(userdata);
}

static void gfx_display_draw_texture(
      gfx_display_t *p_disp,
      gfx_display_ctx_driver_t *dispctx,
      void *userdata,
      unsigned video_width,
      unsigned video_height,
      int x, int y, unsigned w, unsigned h,
      unsigned width, unsigned height,
      float *color, uintptr_t texture,
      gfx_display_ctx_draw_t *draw
      )
{
   if (w == 0 || h == 0)
      return;
   if (!dispctx || !dispctx->draw)
      return;

   draw->width              = w;
   draw->height             = h;
   draw->prim_type          = GFX_DISPLAY_PRIM_TRIANGLESTRIP;
   draw->pipeline_id        = 0;
   draw->texture            = texture;
   draw->x                  = x;
   draw->y                  = height - y;

   dispctx->draw(draw, userdata, video_width, video_height);
}

/* Draw the texture split into 9 sections, without scaling the corners.
 * The middle sections will only scale in the X axis, and the side
 * sections will only scale in the Y axis. */
void gfx_display_draw_texture_slice(
      gfx_display_t *p_disp,
      void *userdata,
      unsigned video_width,
      unsigned video_height,
      int x, int y, unsigned w, unsigned h,
      unsigned new_w, unsigned new_h,
      unsigned width, unsigned height,
      float *color, unsigned offset, float scale_factor, uintptr_t texture)
{
   gfx_display_ctx_draw_t draw;
   gfx_display_ctx_rotate_draw_t rotate_draw;
   struct video_coords coords;
   math_matrix_4x4 mymat;
   gfx_display_ctx_driver_t 
      *dispctx              = p_disp->dispctx;
   float V_BL[2], V_BR[2], V_TL[2], V_TR[2], T_BL[2], T_BR[2], T_TL[2], T_TR[2];
   /* To prevent visible seams between the corners and
    * middle segments of the sliced texture, the texture
    * must be scaled such that its effective size (before
    * expansion of the middle segments) is no greater than
    * the requested display size.
    * > This is consequence of the way textures are rendered
    *   in hardware...
    * > Whenever an image is scaled, the colours at the
    *   transparent edges get interpolated, which means
    *   the colours of the transparent pixels themselves bleed
    *   into the visible area.
    * > This effectively 'blurs' anything that gets scaled
    *   [SIDE NOTE: this causes additional issues if the transparent
    *    pixels have the wrong colour - i.e. if they are black,
    *    every edge gets a nasty dark border...]
    * > This burring is a problem because (by design) the corners
    *   of the sliced texture are drawn at native resolution,
    *   whereas the middle segments are stretched to fit the
    *   requested dimensions. Consequently, the corners are sharp
    *   while the middle segments are blurred.
    * > When *upscaling* the middle segments (i.e. display size
    *   greater than texture size), the visible effects of this
    *   are mostly imperceptible.
    * > When *downscaling* them, however, the interpolation effects
    *   completely dominate the output image - creating an ugly
    *   transition between the corners and middle parts.
    * > Since this is a property of hardware rendering, it is not
    *   practical to fix this 'properly'...
    * > However: An effective workaround is to force downscaling of
    *   the entire texture (including corners) whenever the
    *   requested display size is less than the texture dimensions.
    * > This blurs the corners enough that the corner/middle
    *   transitions are essentially invisible. */
   float max_scale_w = (float)new_w / (float)w;
   float max_scale_h = (float)new_h / (float)h;
   /* Find the minimum of scale_factor, max_scale_w, max_scale_h */
   float slice_scale = (scale_factor < max_scale_w) ?
         (scale_factor < max_scale_h) ? scale_factor : max_scale_h :
         (max_scale_w  < max_scale_h) ? max_scale_w  : max_scale_h;

   /* need space for the coordinates of two triangles in a strip,
    * so 8 vertices */
   float tex_coord[8];
   float vert_coord[8];
   static float colors[16] = { 
      1.0f, 1.0f, 1.0f, 1.0f,
      1.0f, 1.0f, 1.0f, 1.0f,
      1.0f, 1.0f, 1.0f, 1.0f,
      1.0f, 1.0f, 1.0f, 1.0f
   };

   /* normalized width/height of the amount to offset from the corners,
    * for both the vertex and texture coordinates */
   float vert_woff   = (offset * slice_scale) / (float)width;
   float vert_hoff   = (offset * slice_scale) / (float)height;
   float tex_woff    = offset / (float)w;
   float tex_hoff    = offset / (float)h;

   /* the width/height of the middle sections of both the scaled and original image */
   float vert_scaled_mid_width  = (new_w - (offset * slice_scale * 2))
      / (float)width;
   float vert_scaled_mid_height = (new_h - (offset * slice_scale * 2))
      / (float)height;
   float tex_mid_width          = (w - (offset * 2)) / (float)w;
   float tex_mid_height         = (h - (offset * 2)) / (float)h;

   /* normalized coordinates for the start position of the image */
   float norm_x                 = x / (float)width;
   float norm_y                 = (height - y) / (float)height;

   if (width == 0 || height == 0)
      return;
   if (!dispctx || !dispctx->draw)
      return;

   /* the four vertices of the top-left corner of the image,
    * used as a starting point for all the other sections */
   V_BL[0] = norm_x;
   V_BL[1] = norm_y;
   V_BR[0] = norm_x + vert_woff;
   V_BR[1] = norm_y;
   V_TL[0] = norm_x;
   V_TL[1] = norm_y + vert_hoff;
   V_TR[0] = norm_x + vert_woff;
   V_TR[1] = norm_y + vert_hoff;
   T_BL[0] = 0.0f;
   T_BL[1] = tex_hoff;
   T_BR[0] = tex_woff;
   T_BR[1] = tex_hoff;
   T_TL[0] = 0.0f;
   T_TL[1] = 0.0f;
   T_TR[0] = tex_woff;
   T_TR[1] = 0.0f;

   rotate_draw.matrix       = &mymat;
   rotate_draw.rotation     = 0.0;
   rotate_draw.scale_x      = 1.0;
   rotate_draw.scale_y      = 1.0;
   rotate_draw.scale_z      = 1;
   rotate_draw.scale_enable = true;
   coords.vertices          = 4;
   coords.vertex            = vert_coord;
   coords.tex_coord         = tex_coord;
   coords.lut_tex_coord     = NULL;
   draw.width               = width;
   draw.height              = height;
   draw.coords              = &coords;
   draw.matrix_data         = &mymat;
   draw.prim_type           = GFX_DISPLAY_PRIM_TRIANGLESTRIP;
   draw.pipeline_id         = 0;
   coords.color             = (const float*)(color == NULL ? colors : color);

   gfx_display_rotate_z(p_disp, &rotate_draw, userdata);

   draw.texture             = texture;
   draw.x                   = 0;
   draw.y                   = 0;

   /* vertex coords are specfied bottom-up in this order: BL BR TL TR */
   /* texture coords are specfied top-down in this order: BL BR TL TR */

   /* If someone wants to change this to not draw several times, the
    * coordinates will need to be modified because of the triangle strip usage. */

   /* top-left corner */
   vert_coord[0] = V_BL[0];
   vert_coord[1] = V_BL[1];
   vert_coord[2] = V_BR[0];
   vert_coord[3] = V_BR[1];
   vert_coord[4] = V_TL[0];
   vert_coord[5] = V_TL[1];
   vert_coord[6] = V_TR[0];
   vert_coord[7] = V_TR[1];

   tex_coord[0] = T_BL[0];
   tex_coord[1] = T_BL[1];
   tex_coord[2] = T_BR[0];
   tex_coord[3] = T_BR[1];
   tex_coord[4] = T_TL[0];
   tex_coord[5] = T_TL[1];
   tex_coord[6] = T_TR[0];
   tex_coord[7] = T_TR[1];

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* top-middle section */
   vert_coord[0] = V_BL[0] + vert_woff;
   vert_coord[1] = V_BL[1];
   vert_coord[2] = V_BR[0] + vert_scaled_mid_width;
   vert_coord[3] = V_BR[1];
   vert_coord[4] = V_TL[0] + vert_woff;
   vert_coord[5] = V_TL[1];
   vert_coord[6] = V_TR[0] + vert_scaled_mid_width;
   vert_coord[7] = V_TR[1];

   tex_coord[0] = T_BL[0] + tex_woff;
   tex_coord[1] = T_BL[1];
   tex_coord[2] = T_BR[0] + tex_mid_width;
   tex_coord[3] = T_BR[1];
   tex_coord[4] = T_TL[0] + tex_woff;
   tex_coord[5] = T_TL[1];
   tex_coord[6] = T_TR[0] + tex_mid_width;
   tex_coord[7] = T_TR[1];

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* top-right corner */
   vert_coord[0] = V_BL[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[1] = V_BL[1];
   vert_coord[2] = V_BR[0] + vert_scaled_mid_width + vert_woff;
   vert_coord[3] = V_BR[1];
   vert_coord[4] = V_TL[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[5] = V_TL[1];
   vert_coord[6] = V_TR[0] + vert_scaled_mid_width + vert_woff;
   vert_coord[7] = V_TR[1];

   tex_coord[0] = T_BL[0] + tex_woff + tex_mid_width;
   tex_coord[1] = T_BL[1];
   tex_coord[2] = T_BR[0] + tex_mid_width + tex_woff;
   tex_coord[3] = T_BR[1];
   tex_coord[4] = T_TL[0] + tex_woff + tex_mid_width;
   tex_coord[5] = T_TL[1];
   tex_coord[6] = T_TR[0] + tex_mid_width + tex_woff;
   tex_coord[7] = T_TR[1];

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* middle-left section */
   vert_coord[0] = V_BL[0];
   vert_coord[1] = V_BL[1] - vert_scaled_mid_height;
   vert_coord[2] = V_BR[0];
   vert_coord[3] = V_BR[1] - vert_scaled_mid_height;
   vert_coord[4] = V_TL[0];
   vert_coord[5] = V_TL[1] - vert_hoff;
   vert_coord[6] = V_TR[0];
   vert_coord[7] = V_TR[1] - vert_hoff;

   tex_coord[0] = T_BL[0];
   tex_coord[1] = T_BL[1] + tex_mid_height;
   tex_coord[2] = T_BR[0];
   tex_coord[3] = T_BR[1] + tex_mid_height;
   tex_coord[4] = T_TL[0];
   tex_coord[5] = T_TL[1] + tex_hoff;
   tex_coord[6] = T_TR[0];
   tex_coord[7] = T_TR[1] + tex_hoff;

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* center section */
   vert_coord[0] = V_BL[0] + vert_woff;
   vert_coord[1] = V_BL[1] - vert_scaled_mid_height;
   vert_coord[2] = V_BR[0] + vert_scaled_mid_width;
   vert_coord[3] = V_BR[1] - vert_scaled_mid_height;
   vert_coord[4] = V_TL[0] + vert_woff;
   vert_coord[5] = V_TL[1] - vert_hoff;
   vert_coord[6] = V_TR[0] + vert_scaled_mid_width;
   vert_coord[7] = V_TR[1] - vert_hoff;

   tex_coord[0] = T_BL[0] + tex_woff;
   tex_coord[1] = T_BL[1] + tex_mid_height;
   tex_coord[2] = T_BR[0] + tex_mid_width;
   tex_coord[3] = T_BR[1] + tex_mid_height;
   tex_coord[4] = T_TL[0] + tex_woff;
   tex_coord[5] = T_TL[1] + tex_hoff;
   tex_coord[6] = T_TR[0] + tex_mid_width;
   tex_coord[7] = T_TR[1] + tex_hoff;

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* middle-right section */
   vert_coord[0] = V_BL[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[1] = V_BL[1] - vert_scaled_mid_height;
   vert_coord[2] = V_BR[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[3] = V_BR[1] - vert_scaled_mid_height;
   vert_coord[4] = V_TL[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[5] = V_TL[1] - vert_hoff;
   vert_coord[6] = V_TR[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[7] = V_TR[1] - vert_hoff;

   tex_coord[0] = T_BL[0] + tex_woff + tex_mid_width;
   tex_coord[1] = T_BL[1] + tex_mid_height;
   tex_coord[2] = T_BR[0] + tex_woff + tex_mid_width;
   tex_coord[3] = T_BR[1] + tex_mid_height;
   tex_coord[4] = T_TL[0] + tex_woff + tex_mid_width;
   tex_coord[5] = T_TL[1] + tex_hoff;
   tex_coord[6] = T_TR[0] + tex_woff + tex_mid_width;
   tex_coord[7] = T_TR[1] + tex_hoff;

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* bottom-left corner */
   vert_coord[0] = V_BL[0];
   vert_coord[1] = V_BL[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[2] = V_BR[0];
   vert_coord[3] = V_BR[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[4] = V_TL[0];
   vert_coord[5] = V_TL[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[6] = V_TR[0];
   vert_coord[7] = V_TR[1] - vert_hoff - vert_scaled_mid_height;

   tex_coord[0] = T_BL[0];
   tex_coord[1] = T_BL[1] + tex_hoff + tex_mid_height;
   tex_coord[2] = T_BR[0];
   tex_coord[3] = T_BR[1] + tex_hoff + tex_mid_height;
   tex_coord[4] = T_TL[0];
   tex_coord[5] = T_TL[1] + tex_hoff + tex_mid_height;
   tex_coord[6] = T_TR[0];
   tex_coord[7] = T_TR[1] + tex_hoff + tex_mid_height;

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* bottom-middle section */
   vert_coord[0] = V_BL[0] + vert_woff;
   vert_coord[1] = V_BL[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[2] = V_BR[0] + vert_scaled_mid_width;
   vert_coord[3] = V_BR[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[4] = V_TL[0] + vert_woff;
   vert_coord[5] = V_TL[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[6] = V_TR[0] + vert_scaled_mid_width;
   vert_coord[7] = V_TR[1] - vert_hoff - vert_scaled_mid_height;

   tex_coord[0] = T_BL[0] + tex_woff;
   tex_coord[1] = T_BL[1] + tex_hoff + tex_mid_height;
   tex_coord[2] = T_BR[0] + tex_mid_width;
   tex_coord[3] = T_BR[1] + tex_hoff + tex_mid_height;
   tex_coord[4] = T_TL[0] + tex_woff;
   tex_coord[5] = T_TL[1] + tex_hoff + tex_mid_height;
   tex_coord[6] = T_TR[0] + tex_mid_width;
   tex_coord[7] = T_TR[1] + tex_hoff + tex_mid_height;

   dispctx->draw(&draw, userdata, video_width, video_height);

   /* bottom-right corner */
   vert_coord[0] = V_BL[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[1] = V_BL[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[2] = V_BR[0] + vert_scaled_mid_width + vert_woff;
   vert_coord[3] = V_BR[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[4] = V_TL[0] + vert_woff + vert_scaled_mid_width;
   vert_coord[5] = V_TL[1] - vert_hoff - vert_scaled_mid_height;
   vert_coord[6] = V_TR[0] + vert_scaled_mid_width + vert_woff;
   vert_coord[7] = V_TR[1] - vert_hoff - vert_scaled_mid_height;

   tex_coord[0] = T_BL[0] + tex_woff + tex_mid_width;
   tex_coord[1] = T_BL[1] + tex_hoff + tex_mid_height;
   tex_coord[2] = T_BR[0] + tex_woff + tex_mid_width;
   tex_coord[3] = T_BR[1] + tex_hoff + tex_mid_height;
   tex_coord[4] = T_TL[0] + tex_woff + tex_mid_width;
   tex_coord[5] = T_TL[1] + tex_hoff + tex_mid_height;
   tex_coord[6] = T_TR[0] + tex_woff + tex_mid_width;
   tex_coord[7] = T_TR[1] + tex_hoff + tex_mid_height;

   dispctx->draw(&draw, userdata, video_width, video_height);
}

void gfx_display_rotate_z(gfx_display_t *p_disp,
      gfx_display_ctx_rotate_draw_t *draw, void *data)
{
   math_matrix_4x4 matrix_rotated, matrix_scaled;
   math_matrix_4x4                *b = NULL;
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;

   if (
         !draw                       ||
         !dispctx                  ||
         !dispctx->get_default_mvp ||
         dispctx->handles_transform
      )
      return;

   b = (math_matrix_4x4*)dispctx->get_default_mvp(data);

   if (!b)
      return;

   matrix_4x4_rotate_z(matrix_rotated, draw->rotation);
   matrix_4x4_multiply(*draw->matrix, matrix_rotated, *b);

   if (!draw->scale_enable)
      return;

   matrix_4x4_scale(matrix_scaled,
         draw->scale_x, draw->scale_y, draw->scale_z);
   matrix_4x4_multiply(*draw->matrix, matrix_scaled, *draw->matrix);
}

/*
 * Draw a hardware cursor on top of the screen for the mouse.
 */
void gfx_display_draw_cursor(
      gfx_display_t *p_disp,
      void *userdata,
      unsigned video_width,
      unsigned video_height,
      bool cursor_visible,
      float *color, float cursor_size, uintptr_t texture,
      float x, float y, unsigned width, unsigned height)
{
   gfx_display_ctx_draw_t draw;
   struct video_coords coords;
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;

   if (!dispctx)
      return;

   coords.vertices      = 4;
   coords.vertex        = NULL;
   coords.tex_coord     = NULL;
   coords.lut_tex_coord = NULL;
   coords.color         = (const float*)color;

   draw.x               = x - (cursor_size / 2);
   draw.y               = (int)height - y - (cursor_size / 2);
   draw.width           = cursor_size;
   draw.height          = cursor_size;
   draw.coords          = &coords;
   draw.matrix_data     = NULL;
   draw.texture         = texture;
   draw.prim_type       = GFX_DISPLAY_PRIM_TRIANGLESTRIP;
   draw.pipeline_id     = 0;
   draw.scale_factor    = 1.0f;
   draw.rotation        = 0.0f;

   if (dispctx->blend_begin)
      dispctx->blend_begin(userdata);
   if (dispctx->draw)
      dispctx->draw(&draw, userdata, video_width, video_height);
   if (dispctx->blend_end)
      dispctx->blend_end(userdata);
}

/* Setup: Initializes the font associated
 * to the menu driver */
font_data_t *gfx_display_font(
      gfx_display_t *p_disp,
      enum application_special_type type,
      float menu_font_size,
      bool is_threaded)
{
   char fontpath[PATH_MAX_LENGTH];

   fontpath[0] = '\0';

   fill_pathname_application_special(
         fontpath, sizeof(fontpath), type);

   return gfx_display_font_file(p_disp, fontpath, menu_font_size, is_threaded);
}

/* Returns the OSK key at a given position */
int gfx_display_osk_ptr_at_pos(void *data, int x, int y,
      unsigned width, unsigned height)
{
   unsigned i;
   int ptr_width  = width / 11;
   int ptr_height = height / 10;

   if (ptr_width >= ptr_height)
      ptr_width = ptr_height;

   for (i = 0; i < 44; i++)
   {
      int line_y    = (i / 11)*height/10.0;
      int ptr_x     = width/2.0 - (11*ptr_width)/2.0 + (i % 11) * ptr_width;
      int ptr_y     = height/2.0 + ptr_height*1.5 + line_y - ptr_height;

      if (x > ptr_x && x < ptr_x + ptr_width
       && y > ptr_y && y < ptr_y + ptr_height)
         return i;
   }

   return -1;
}

/* Get the display framebuffer's size dimensions. */
void gfx_display_get_fb_size(unsigned *fb_width,
      unsigned *fb_height, size_t *fb_pitch)
{
   gfx_display_t *p_disp = disp_get_ptr();
   *fb_width             = p_disp->framebuf_width;
   *fb_height            = p_disp->framebuf_height;
   *fb_pitch             = p_disp->framebuf_pitch;
}

/* Set the display framebuffer's width. */
void gfx_display_set_width(unsigned width)
{
   gfx_display_t *p_disp  = disp_get_ptr();
   p_disp->framebuf_width = width;
}

/* Set the display framebuffer's height. */
void gfx_display_set_height(unsigned height)
{
   gfx_display_t *p_disp   = disp_get_ptr();
   p_disp->framebuf_height = height;
}

void gfx_display_set_framebuffer_pitch(size_t pitch)
{
   gfx_display_t *p_disp   = disp_get_ptr();
   p_disp->framebuf_pitch = pitch;
}

void gfx_display_set_msg_force(bool state)
{
   gfx_display_t *p_disp   = disp_get_ptr();
   p_disp->msg_force       = state;
}

void gfx_display_draw_keyboard(
      gfx_display_t *p_disp,
      void *userdata,
      unsigned video_width,
      unsigned video_height,
      uintptr_t hover_texture,
      const font_data_t *font,
      char *grid[], unsigned id,
      unsigned text_color)
{
   unsigned i;
   int ptr_width, ptr_height;
   gfx_display_ctx_driver_t *dispctx = p_disp->dispctx;

   static float white[16] =  {
      1.00, 1.00, 1.00, 1.00,
      1.00, 1.00, 1.00, 1.00,
      1.00, 1.00, 1.00, 1.00,
      1.00, 1.00, 1.00, 1.00,
   };
   static float osk_dark[16] =  {
      0.00, 0.00, 0.00, 0.85,
      0.00, 0.00, 0.00, 0.85,
      0.00, 0.00, 0.00, 0.85,
      0.00, 0.00, 0.00, 0.85,
   };
   struct video_coords coords;
   gfx_display_ctx_draw_t draw;
   math_matrix_4x4 mymat;
   gfx_display_ctx_rotate_draw_t rotate_draw;
   rotate_draw.matrix       = &mymat;
   rotate_draw.rotation     = 0.0;
   rotate_draw.scale_x      = 1.0;
   rotate_draw.scale_y      = 1.0;
   rotate_draw.scale_z      = 1;
   rotate_draw.scale_enable = true;

   coords.vertices          = 4;
   coords.vertex            = NULL;
   coords.tex_coord         = NULL;
   coords.lut_tex_coord     = NULL;
   coords.color             = (const float*)&white[0];

   gfx_display_draw_quad(
         p_disp,
         userdata,
         video_width,
         video_height,
         0,
         video_height / 2.0,
         video_width,
         video_height / 2.0,
         video_width,
         video_height,
         &osk_dark[0]);

   ptr_width  = video_width  / 11;
   ptr_height = video_height / 10;

   if (ptr_width >= ptr_height)
      ptr_width = ptr_height;

   gfx_display_rotate_z(p_disp, &rotate_draw, userdata);

   draw.coords             = &coords;
   draw.matrix_data        = &mymat;

   for (i = 0; i < 44; i++)
   {
      int line_y     = (i / 11) * video_height / 10.0;
      unsigned color = 0xffffffff;

      if (i == id)
      {
         if (dispctx && dispctx->blend_begin)
            dispctx->blend_begin(userdata);

         gfx_display_draw_texture(
               p_disp,
               dispctx,
               userdata,
               video_width,
               video_height,
               video_width / 2.0 - (11 * ptr_width) / 2.0 + (i % 11) 
               * ptr_width,
               video_height / 2.0 + ptr_height * 1.5 + line_y,
               ptr_width, ptr_height,
               video_width,
               video_height,
               &white[0],
               hover_texture,
               &draw
               );

         if (dispctx && dispctx->blend_end)
            dispctx->blend_end(userdata);

         color = text_color;
      }

      gfx_display_draw_text(font, grid[i],
            video_width/2.0 - (11*ptr_width)/2.0 + (i % 11)
            * ptr_width + ptr_width/2.0,
            video_height / 2.0 + ptr_height + line_y + font->size / 3,
            video_width,
            video_height,
            color,
            TEXT_ALIGN_CENTER,
            1.0f,
            false, 0, false);
   }
}

/* NOTE: Reads image from file */
bool gfx_display_reset_textures_list(
      const char *texture_path, const char *iconpath,
      uintptr_t *item, enum texture_filter_type filter_type,
      unsigned *width, unsigned *height)
{
   char texpath[PATH_MAX_LENGTH];
   struct texture_image ti;

   texpath[0]                    = '\0';

   ti.width                      = 0;
   ti.height                     = 0;
   ti.pixels                     = NULL;
   ti.supports_rgba              = video_driver_supports_rgba();

   if (string_is_empty(texture_path))
      return false;

   fill_pathname_join(texpath, iconpath, texture_path, sizeof(texpath));

   if (!image_texture_load(&ti, texpath))
      return false;

   if (width)
      *width = ti.width;

   if (height)
      *height = ti.height;

   video_driver_texture_load(&ti,
         filter_type, item);
   image_texture_free(&ti);

   return true;
}

/* Teardown; deinitializes and frees all
 * fonts associated to the display driver */
void gfx_display_font_free(font_data_t *font)
{
   font_driver_free(font);
}

void gfx_display_init_white_texture(uintptr_t white_texture)
{
   struct texture_image ti;
   static const uint8_t white_data[] = { 0xff, 0xff, 0xff, 0xff };

   ti.width  = 1;
   ti.height = 1;
   ti.pixels = (uint32_t*)&white_data;

   video_driver_texture_load(&ti,
         TEXTURE_FILTER_NEAREST, &gfx_display_white_texture);
}

void gfx_display_free(void)
{
   gfx_display_t           *p_disp   = disp_get_ptr();
   video_coord_array_free(&p_disp->dispca);

   p_disp->msg_force           = false;
   p_disp->header_height       = 0;
   p_disp->framebuf_width      = 0;
   p_disp->framebuf_height     = 0;
   p_disp->framebuf_pitch      = 0;
   p_disp->has_windowed        = false;
   p_disp->dispctx             = NULL;
}

void gfx_display_init(void)
{
   gfx_display_t       *p_disp   = disp_get_ptr();
   video_coord_array_t *p_dispca = &p_disp->dispca;

   p_disp->has_windowed          = video_driver_has_windowed();
   p_dispca->allocated           =  0;
}

bool gfx_display_driver_exists(const char *s)
{
   unsigned i;
   for (i = 0; i < ARRAY_SIZE(gfx_display_ctx_drivers); i++)
   {
      if (string_is_equal(s, gfx_display_ctx_drivers[i]->ident))
         return true;
   }

   return false;
}

bool gfx_display_init_first_driver(gfx_display_t *p_disp,
      bool video_is_threaded)
{
   unsigned i;

   for (i = 0; gfx_display_ctx_drivers[i]; i++)
   {
      if (!gfx_display_check_compatibility(
               gfx_display_ctx_drivers[i]->type,
               video_is_threaded))
         continue;

      RARCH_LOG("[Display]: Found display driver: \"%s\".\n",
            gfx_display_ctx_drivers[i]->ident);
      p_disp->dispctx = gfx_display_ctx_drivers[i];
      return true;
   }
   return false;
}
