mesa/state_tracker/st_manager.c

/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 2010 LunarG Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *    Chia-I Wu <olv@lunarg.com>
 */

#include "main/mtypes.h"
#include "main/extensions.h"
#include "main/context.h"
#include "main/debug_output.h"
#include "main/framebuffer.h"
#include "main/glthread.h"
#include "main/texobj.h"
#include "main/teximage.h"
#include "main/texstate.h"
#include "main/errors.h"
#include "main/framebuffer.h"
#include "main/fbobject.h"
#include "main/renderbuffer.h"
#include "main/version.h"
#include "util/hash_table.h"
#include "st_texture.h"

#include "st_context.h"
#include "st_debug.h"
#include "st_extensions.h"
#include "st_format.h"
#include "st_cb_bitmap.h"
#include "st_cb_flush.h"
#include "st_manager.h"
#include "st_sampler_view.h"
#include "st_util.h"

#include "pipe/p_context.h"
#include "pipe/p_screen.h"
#include "util/format/u_format.h"
#include "util/u_helpers.h"
#include "util/u_pointer.h"
#include "util/u_inlines.h"
#include "util/u_atomic.h"
#include "util/u_surface.h"
#include "util/list.h"
#include "util/u_memory.h"
#include "util/perf/cpu_trace.h"

struct hash_table;

struct st_screen
{
   struct hash_table *drawable_ht; /* pipe_frontend_drawable objects hash table */
   simple_mtx_t st_mutex;
};

/**
 * Cast wrapper to convert a struct gl_framebuffer to an gl_framebuffer.
 * Return NULL if the struct gl_framebuffer is a user-created framebuffer.
 * We'll only return non-null for window system framebuffers.
 * Note that this function may fail.
 */
static inline struct gl_framebuffer *
st_ws_framebuffer(struct gl_framebuffer *fb)
{
   /* FBO cannot be casted.  See st_new_framebuffer */
   if (fb && _mesa_is_winsys_fbo(fb) &&
       fb != _mesa_get_incomplete_framebuffer())
      return fb;
   return NULL;
}

/**
 * Map an attachment to a buffer index.
 */
static inline gl_buffer_index
attachment_to_buffer_index(enum st_attachment_type statt)
{
   gl_buffer_index index;

   switch (statt) {
   case ST_ATTACHMENT_FRONT_LEFT:
      index = BUFFER_FRONT_LEFT;
      break;
   case ST_ATTACHMENT_BACK_LEFT:
      index = BUFFER_BACK_LEFT;
      break;
   case ST_ATTACHMENT_FRONT_RIGHT:
      index = BUFFER_FRONT_RIGHT;
      break;
   case ST_ATTACHMENT_BACK_RIGHT:
      index = BUFFER_BACK_RIGHT;
      break;
   case ST_ATTACHMENT_DEPTH_STENCIL:
      index = BUFFER_DEPTH;
      break;
   case ST_ATTACHMENT_ACCUM:
      index = BUFFER_ACCUM;
      break;
   default:
      index = BUFFER_COUNT;
      break;
   }

   return index;
}


/**
 * Map a buffer index to an attachment.
 */
static inline enum st_attachment_type
buffer_index_to_attachment(gl_buffer_index index)
{
   enum st_attachment_type statt;

   switch (index) {
   case BUFFER_FRONT_LEFT:
      statt = ST_ATTACHMENT_FRONT_LEFT;
      break;
   case BUFFER_BACK_LEFT:
      statt = ST_ATTACHMENT_BACK_LEFT;
      break;
   case BUFFER_FRONT_RIGHT:
      statt = ST_ATTACHMENT_FRONT_RIGHT;
      break;
   case BUFFER_BACK_RIGHT:
      statt = ST_ATTACHMENT_BACK_RIGHT;
      break;
   case BUFFER_DEPTH:
      statt = ST_ATTACHMENT_DEPTH_STENCIL;
      break;
   case BUFFER_ACCUM:
      statt = ST_ATTACHMENT_ACCUM;
      break;
   default:
      statt = ST_ATTACHMENT_INVALID;
      break;
   }

   return statt;
}


/**
 * Make sure a context picks up the latest cached state of the
 * drawables it binds to.
 */
static void
st_context_validate(struct st_context *st,
                    struct gl_framebuffer *stdraw,
                    struct gl_framebuffer *stread)
{
    if (stdraw && stdraw->stamp != st->draw_stamp) {
       st->ctx->NewDriverState |= ST_NEW_FRAMEBUFFER;
       _mesa_resize_framebuffer(st->ctx, stdraw,
                                stdraw->Width,
                                stdraw->Height);
       st->draw_stamp = stdraw->stamp;
    }

    if (stread && stread->stamp != st->read_stamp) {
       if (stread != stdraw) {
          st->ctx->NewDriverState |= ST_NEW_FRAMEBUFFER;
          _mesa_resize_framebuffer(st->ctx, stread,
                                   stread->Width,
                                   stread->Height);
       }
       st->read_stamp = stread->stamp;
    }
}


void
st_set_ws_renderbuffer_surface(struct gl_renderbuffer *rb,
                               struct pipe_surface *surf)
{
   pipe_surface_reference(&rb->surface_srgb, NULL);
   pipe_surface_reference(&rb->surface_linear, NULL);

   if (util_format_is_srgb(surf->format))
      pipe_surface_reference(&rb->surface_srgb, surf);
   else
      pipe_surface_reference(&rb->surface_linear, surf);

   rb->surface = surf; /* just assign, don't ref */
   pipe_resource_reference(&rb->texture, surf->texture);

   rb->Width = surf->width;
   rb->Height = surf->height;
}


/**
 * Validate a framebuffer to make sure up-to-date pipe_textures are used.
 * The context is only used for creating pipe surfaces and for calling
 * _mesa_resize_framebuffer().
 * (That should probably be rethought, since those surfaces become
 * drawable state, not context state, and can be freed by another pipe
 * context).
 */
static void
st_framebuffer_validate(struct gl_framebuffer *stfb,
                        struct st_context *st)
{
   struct pipe_resource *textures[ST_ATTACHMENT_COUNT];
   struct pipe_resource *resolve = NULL;
   uint width, height;
   unsigned i;
   bool changed = false;
   int32_t new_stamp;

   new_stamp = p_atomic_read(&stfb->drawable->stamp);
   if (stfb->drawable_stamp == new_stamp)
      return;

   memset(textures, 0, stfb->num_statts * sizeof(textures[0]));

   /* validate the fb */
   do {
      if (!stfb->drawable->validate(st, stfb->drawable, stfb->statts,
                                 stfb->num_statts, textures, &resolve))
         return;

      stfb->drawable_stamp = new_stamp;
      new_stamp = p_atomic_read(&stfb->drawable->stamp);
   } while(stfb->drawable_stamp != new_stamp);

   width = stfb->Width;
   height = stfb->Height;

   for (i = 0; i < stfb->num_statts; i++) {
      struct gl_renderbuffer *rb;
      struct pipe_surface *ps, surf_tmpl;
      gl_buffer_index idx;

      if (!textures[i])
         continue;

      idx = attachment_to_buffer_index(stfb->statts[i]);
      if (idx >= BUFFER_COUNT) {
         pipe_resource_reference(&textures[i], NULL);
         continue;
      }

      rb = stfb->Attachment[idx].Renderbuffer;
      assert(rb);
      if (rb->texture == textures[i] &&
          rb->Width == textures[i]->width0 &&
          rb->Height == textures[i]->height0) {
         pipe_resource_reference(&textures[i], NULL);
         continue;
      }

      u_surface_default_template(&surf_tmpl, textures[i]);
      ps = st->pipe->create_surface(st->pipe, textures[i], &surf_tmpl);
      if (ps) {
         st_set_ws_renderbuffer_surface(rb, ps);
         pipe_surface_reference(&ps, NULL);

         changed = true;

         width = rb->Width;
         height = rb->Height;
      }

      pipe_resource_reference(&textures[i], NULL);
   }

   changed |= resolve != stfb->resolve;
   /* ref is removed here */
   pipe_resource_reference(&stfb->resolve, NULL);
   /* ref is taken here */
   stfb->resolve = resolve;

   if (changed) {
      ++stfb->stamp;
      _mesa_resize_framebuffer(st->ctx, stfb, width, height);
   }
}

/**
 * Return true if the visual has the specified buffers.
 */
static inline bool
st_visual_have_buffers(const struct st_visual *visual, unsigned mask)
{
   return ((visual->buffer_mask & mask) == mask);
}

/**
 * Update the attachments to validate by looping the existing renderbuffers.
 */
static void
st_framebuffer_update_attachments(struct gl_framebuffer *stfb)
{
   gl_buffer_index idx;

   stfb->num_statts = 0;

   for (enum st_attachment_type i = 0; i < ST_ATTACHMENT_COUNT; i++)
      stfb->statts[i] = ST_ATTACHMENT_INVALID;

   for (idx = 0; idx < BUFFER_COUNT; idx++) {
      struct gl_renderbuffer *rb;
      enum st_attachment_type statt;

      rb = stfb->Attachment[idx].Renderbuffer;
      if (!rb || rb->software)
         continue;

      statt = buffer_index_to_attachment(idx);
      if (statt != ST_ATTACHMENT_INVALID &&
          st_visual_have_buffers(stfb->drawable->visual, 1 << statt))
         stfb->statts[stfb->num_statts++] = statt;
   }
   stfb->stamp++;
}

/**
 * Allocate a renderbuffer for an on-screen window (not a user-created
 * renderbuffer).  The window system code determines the format.
 */
static struct gl_renderbuffer *
st_new_renderbuffer_fb(enum pipe_format format, unsigned samples, bool sw)
{
   struct gl_renderbuffer *rb;

   rb = CALLOC_STRUCT(gl_renderbuffer);
   if (!rb) {
      _mesa_error(NULL, GL_OUT_OF_MEMORY, "creating renderbuffer");
      return NULL;
   }

   _mesa_init_renderbuffer(rb, 0);
   rb->NumSamples = samples;
   rb->NumStorageSamples = samples;
   rb->Format = st_pipe_format_to_mesa_format(format);
   rb->_BaseFormat = _mesa_get_format_base_format(rb->Format);
   rb->software = sw;

   switch (format) {
   case PIPE_FORMAT_B10G10R10A2_UNORM:
   case PIPE_FORMAT_R10G10B10A2_UNORM:
      rb->InternalFormat = GL_RGB10_A2;
      break;
   case PIPE_FORMAT_R10G10B10X2_UNORM:
   case PIPE_FORMAT_B10G10R10X2_UNORM:
      rb->InternalFormat = GL_RGB10;
      break;
   case PIPE_FORMAT_R8G8B8A8_UNORM:
   case PIPE_FORMAT_B8G8R8A8_UNORM:
   case PIPE_FORMAT_A8R8G8B8_UNORM:
      rb->InternalFormat = GL_RGBA8;
      break;
   case PIPE_FORMAT_R8G8B8X8_UNORM:
   case PIPE_FORMAT_B8G8R8X8_UNORM:
   case PIPE_FORMAT_X8R8G8B8_UNORM:
   case PIPE_FORMAT_R8G8B8_UNORM:
      rb->InternalFormat = GL_RGB8;
      break;
   case PIPE_FORMAT_R8G8B8A8_SRGB:
   case PIPE_FORMAT_B8G8R8A8_SRGB:
   case PIPE_FORMAT_A8R8G8B8_SRGB:
      rb->InternalFormat = GL_SRGB8_ALPHA8;
      break;
   case PIPE_FORMAT_R8G8B8X8_SRGB:
   case PIPE_FORMAT_B8G8R8X8_SRGB:
   case PIPE_FORMAT_X8R8G8B8_SRGB:
      rb->InternalFormat = GL_SRGB8;
      break;
   case PIPE_FORMAT_B5G5R5A1_UNORM:
      rb->InternalFormat = GL_RGB5_A1;
      break;
   case PIPE_FORMAT_B4G4R4A4_UNORM:
      rb->InternalFormat = GL_RGBA4;
      break;
   case PIPE_FORMAT_B5G6R5_UNORM:
      rb->InternalFormat = GL_RGB565;
      break;
   case PIPE_FORMAT_Z16_UNORM:
      rb->InternalFormat = GL_DEPTH_COMPONENT16;
      break;
   case PIPE_FORMAT_Z32_UNORM:
      rb->InternalFormat = GL_DEPTH_COMPONENT32;
      break;
   case PIPE_FORMAT_Z24_UNORM_S8_UINT:
   case PIPE_FORMAT_S8_UINT_Z24_UNORM:
      rb->InternalFormat = GL_DEPTH24_STENCIL8_EXT;
      break;
   case PIPE_FORMAT_Z24X8_UNORM:
   case PIPE_FORMAT_X8Z24_UNORM:
      rb->InternalFormat = GL_DEPTH_COMPONENT24;
      break;
   case PIPE_FORMAT_S8_UINT:
      rb->InternalFormat = GL_STENCIL_INDEX8_EXT;
      break;
   case PIPE_FORMAT_R16G16B16A16_SNORM:
      /* accum buffer */
      rb->InternalFormat = GL_RGBA16_SNORM;
      break;
   case PIPE_FORMAT_R16G16B16A16_UNORM:
      rb->InternalFormat = GL_RGBA16;
      break;
   case PIPE_FORMAT_R16G16B16_UNORM:
      rb->InternalFormat = GL_RGB16;
      break;
   case PIPE_FORMAT_R8_UNORM:
      rb->InternalFormat = GL_R8;
      break;
   case PIPE_FORMAT_R8G8_UNORM:
      rb->InternalFormat = GL_RG8;
      break;
   case PIPE_FORMAT_R16_UNORM:
      rb->InternalFormat = GL_R16;
      break;
   case PIPE_FORMAT_R16G16_UNORM:
      rb->InternalFormat = GL_RG16;
      break;
   case PIPE_FORMAT_R32G32B32A32_FLOAT:
      rb->InternalFormat = GL_RGBA32F;
      break;
   case PIPE_FORMAT_R32G32B32X32_FLOAT:
   case PIPE_FORMAT_R32G32B32_FLOAT:
      rb->InternalFormat = GL_RGB32F;
      break;
   case PIPE_FORMAT_R16G16B16A16_FLOAT:
      rb->InternalFormat = GL_RGBA16F;
      break;
   case PIPE_FORMAT_R16G16B16X16_FLOAT:
      rb->InternalFormat = GL_RGB16F;
      break;
   default:
      _mesa_problem(NULL,
                    "Unexpected format %s in st_new_renderbuffer_fb",
                    util_format_name(format));
      FREE(rb);
      return NULL;
   }

   rb->surface = NULL;

   return rb;
}

/**
 * Add a renderbuffer to the framebuffer.  The framebuffer is one that
 * corresponds to a window and is not a user-created FBO.
 */
static bool
st_framebuffer_add_renderbuffer(struct gl_framebuffer *stfb,
                                gl_buffer_index idx, bool prefer_srgb)
{
   struct gl_renderbuffer *rb;
   enum pipe_format format;
   bool sw;

   assert(_mesa_is_winsys_fbo(stfb));

   /* do not distinguish depth/stencil buffers */
   if (idx == BUFFER_STENCIL)
      idx = BUFFER_DEPTH;

   switch (idx) {
   case BUFFER_DEPTH:
      format = stfb->drawable->visual->depth_stencil_format;
      sw = false;
      break;
   case BUFFER_ACCUM:
      format = stfb->drawable->visual->accum_format;
      sw = true;
      break;
   default:
      format = stfb->drawable->visual->color_format;
      if (prefer_srgb)
         format = util_format_srgb(format);
      sw = false;
      break;
   }

   if (format == PIPE_FORMAT_NONE)
      return false;

   rb = st_new_renderbuffer_fb(format, stfb->drawable->visual->samples, sw);
   if (!rb)
      return false;

   if (idx != BUFFER_DEPTH) {
      _mesa_attach_and_own_rb(stfb, idx, rb);
      return true;
   }

   bool rb_ownership_taken = false;
   if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0)) {
      _mesa_attach_and_own_rb(stfb, BUFFER_DEPTH, rb);
      rb_ownership_taken = true;
   }

   if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1)) {
      if (rb_ownership_taken)
         _mesa_attach_and_reference_rb(stfb, BUFFER_STENCIL, rb);
      else
         _mesa_attach_and_own_rb(stfb, BUFFER_STENCIL, rb);
   }

   return true;
}


/**
 * Intialize a struct gl_config from a visual.
 */
static void
st_visual_to_context_mode(const struct st_visual *visual,
                          struct gl_config *mode)
{
   memset(mode, 0, sizeof(*mode));

   if (st_visual_have_buffers(visual, ST_ATTACHMENT_BACK_LEFT_MASK))
      mode->doubleBufferMode = GL_TRUE;

   if (st_visual_have_buffers(visual,
            ST_ATTACHMENT_FRONT_RIGHT_MASK | ST_ATTACHMENT_BACK_RIGHT_MASK))
      mode->stereoMode = GL_TRUE;

   if (visual->color_format != PIPE_FORMAT_NONE) {
      mode->redBits =
         util_format_get_component_bits(visual->color_format,
               UTIL_FORMAT_COLORSPACE_RGB, 0);
      mode->greenBits =
         util_format_get_component_bits(visual->color_format,
               UTIL_FORMAT_COLORSPACE_RGB, 1);
      mode->blueBits =
         util_format_get_component_bits(visual->color_format,
               UTIL_FORMAT_COLORSPACE_RGB, 2);
      mode->alphaBits =
         util_format_get_component_bits(visual->color_format,
               UTIL_FORMAT_COLORSPACE_RGB, 3);

      mode->rgbBits = mode->redBits +
         mode->greenBits + mode->blueBits + mode->alphaBits;
      mode->sRGBCapable = util_format_is_srgb(visual->color_format);
      mode->floatMode = util_format_is_float(visual->color_format);
   }

   if (visual->depth_stencil_format != PIPE_FORMAT_NONE) {
      mode->depthBits =
         util_format_get_component_bits(visual->depth_stencil_format,
               UTIL_FORMAT_COLORSPACE_ZS, 0);
      mode->stencilBits =
         util_format_get_component_bits(visual->depth_stencil_format,
               UTIL_FORMAT_COLORSPACE_ZS, 1);
   }

   if (visual->accum_format != PIPE_FORMAT_NONE) {
      mode->accumRedBits =
         util_format_get_component_bits(visual->accum_format,
               UTIL_FORMAT_COLORSPACE_RGB, 0);
      mode->accumGreenBits =
         util_format_get_component_bits(visual->accum_format,
               UTIL_FORMAT_COLORSPACE_RGB, 1);
      mode->accumBlueBits =
         util_format_get_component_bits(visual->accum_format,
               UTIL_FORMAT_COLORSPACE_RGB, 2);
      mode->accumAlphaBits =
         util_format_get_component_bits(visual->accum_format,
               UTIL_FORMAT_COLORSPACE_RGB, 3);
   }

   if (visual->samples > 1) {
      mode->samples = visual->samples;
   }
}


/**
 * Create a framebuffer from a manager interface.
 */
static struct gl_framebuffer *
st_framebuffer_create(struct st_context *st,
                      struct pipe_frontend_drawable *drawable)
{
   struct gl_framebuffer *stfb;
   struct gl_config mode;
   gl_buffer_index idx;
   bool prefer_srgb = false;

   if (!drawable)
      return NULL;

   stfb = CALLOC_STRUCT(gl_framebuffer);
   if (!stfb)
      return NULL;

   st_visual_to_context_mode(drawable->visual, &mode);

   /*
    * For desktop GL, sRGB framebuffer write is controlled by both the
    * capability of the framebuffer and GL_FRAMEBUFFER_SRGB.  We should
    * advertise the capability when the pipe driver (and core Mesa) supports
    * it so that applications can enable sRGB write when they want to.
    *
    * This is not to be confused with GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB.  When
    * the attribute is GLX_TRUE, it tells the st manager to pick a color
    * format such that util_format_srgb(visual->color_format) can be supported
    * by the pipe driver.  We still need to advertise the capability here.
    *
    * For GLES, however, sRGB framebuffer write is initially only controlled
    * by the capability of the framebuffer, with GL_EXT_sRGB_write_control
    * control is given back to the applications, but GL_FRAMEBUFFER_SRGB is
    * still enabled by default since this is the behaviour when
    * EXT_sRGB_write_control is not available. Since GL_EXT_sRGB_write_control
    * brings GLES on par with desktop GLs EXT_framebuffer_sRGB, in mesa this
    * is also expressed by using the same extension flag
    */
   if (_mesa_has_EXT_framebuffer_sRGB(st->ctx)) {
      struct pipe_screen *screen = st->screen;
      const enum pipe_format srgb_format =
         util_format_srgb(drawable->visual->color_format);

      if (srgb_format != PIPE_FORMAT_NONE &&
          st_pipe_format_to_mesa_format(srgb_format) != MESA_FORMAT_NONE &&
          screen->is_format_supported(screen, srgb_format,
                                      PIPE_TEXTURE_2D, drawable->visual->samples,
                                      drawable->visual->samples,
                                      (PIPE_BIND_DISPLAY_TARGET |
                                       PIPE_BIND_RENDER_TARGET))) {
         mode.sRGBCapable = GL_TRUE;
         /* Since GL_FRAMEBUFFER_SRGB is enabled by default on GLES we must not
          * create renderbuffers with an sRGB format derived from the
          * visual->color_format, but we still want sRGB for desktop GL.
          */
         prefer_srgb = _mesa_is_desktop_gl(st->ctx);
      }
   }

   _mesa_initialize_window_framebuffer(stfb, &mode);

   stfb->drawable = drawable;
   stfb->drawable_ID = drawable->ID;
   stfb->drawable_stamp = p_atomic_read(&drawable->stamp) - 1;

   /* add the color buffer */
   idx = stfb->_ColorDrawBufferIndexes[0];
   if (!st_framebuffer_add_renderbuffer(stfb, idx, prefer_srgb)) {
      FREE(stfb);
      return NULL;
   }

   st_framebuffer_add_renderbuffer(stfb, BUFFER_DEPTH, false);
   st_framebuffer_add_renderbuffer(stfb, BUFFER_ACCUM, false);

   stfb->stamp = 0;
   st_framebuffer_update_attachments(stfb);

   return stfb;
}


static bool
drawable_lookup(struct pipe_frontend_screen *fscreen,
                const struct pipe_frontend_drawable *drawable,
                uint32_t drawable_ID)
{
   struct st_screen *screen =
      (struct st_screen *)fscreen->st_screen;
   struct hash_entry *entry;

   assert(screen);
   assert(screen->drawable_ht);

   simple_mtx_lock(&screen->st_mutex);
   entry = _mesa_hash_table_search_pre_hashed(screen->drawable_ht, drawable_ID, drawable);
   simple_mtx_unlock(&screen->st_mutex);

   return entry != NULL;
}


static bool
drawable_insert(struct pipe_frontend_screen *fscreen,
                struct pipe_frontend_drawable *drawable)
{
   struct st_screen *screen =
      (struct st_screen *)fscreen->st_screen;
   struct hash_entry *entry;

   assert(screen);
   assert(screen->drawable_ht);

   simple_mtx_lock(&screen->st_mutex);
   entry = _mesa_hash_table_insert_pre_hashed(screen->drawable_ht, drawable->ID, drawable, drawable);
   simple_mtx_unlock(&screen->st_mutex);

   return entry != NULL;
}


static void
drawable_remove(struct pipe_frontend_screen *fscreen,
                struct pipe_frontend_drawable *drawable)
{
   struct st_screen *screen =
      (struct st_screen *)fscreen->st_screen;
   struct hash_entry *entry;

   if (!screen || !screen->drawable_ht)
      return;

   simple_mtx_lock(&screen->st_mutex);
   entry = _mesa_hash_table_search_pre_hashed(screen->drawable_ht, drawable->ID, drawable);
   if (!entry)
      goto unlock;

   _mesa_hash_table_remove(screen->drawable_ht, entry);

unlock:
   simple_mtx_unlock(&screen->st_mutex);
}


/**
 * The framebuffer interface object is no longer valid.
 * Remove the object from the framebuffer interface hash table.
 */
void
st_api_destroy_drawable(struct pipe_frontend_drawable *drawable)
{
   if (!drawable)
      return;

   drawable_remove(drawable->fscreen, drawable);
}


/**
 * Purge the winsys buffers list to remove any references to
 * non-existing framebuffer interface objects.
 */
static void
st_framebuffers_purge(struct st_context *st)
{
   struct pipe_frontend_screen *fscreen = st->frontend_screen;
   struct gl_framebuffer *stfb, *next;

   assert(fscreen);

   LIST_FOR_EACH_ENTRY_SAFE_REV(stfb, next, &st->winsys_buffers, head) {
      struct pipe_frontend_drawable *drawable = stfb->drawable;

      assert(drawable);

      /**
       * If the corresponding framebuffer interface object no longer exists,
       * remove the framebuffer object from the context's winsys buffers list,
       * and unreference the framebuffer object, so its resources can be
       * deleted.
       */
      if (!drawable_lookup(fscreen, drawable, stfb->drawable_ID)) {
         list_del(&stfb->head);
         _mesa_reference_framebuffer(&stfb, NULL);
      }
   }
}


void
st_context_flush(struct st_context *st, unsigned flags,
                 struct pipe_fence_handle **fence,
                 void (*before_flush_cb) (void*), void* args)
{
   unsigned pipe_flags = 0;

   MESA_TRACE_FUNC();

   if (flags & ST_FLUSH_END_OF_FRAME)
      pipe_flags |= PIPE_FLUSH_END_OF_FRAME;
   if (flags & ST_FLUSH_FENCE_FD)
      pipe_flags |= PIPE_FLUSH_FENCE_FD;

   /* We can do these in any order because FLUSH_VERTICES will also flush
    * the bitmap cache if there are any unflushed vertices.
    */
   st_flush_bitmap_cache(st);
   FLUSH_VERTICES(st->ctx, 0, 0);

   /* Notify the caller that we're ready to flush */
   if (before_flush_cb)
      before_flush_cb(args);
   st_flush(st, fence, pipe_flags);

   if ((flags & ST_FLUSH_WAIT) && fence && *fence) {
      st->screen->fence_finish(st->screen, NULL, *fence,
                                     OS_TIMEOUT_INFINITE);
      st->screen->fence_reference(st->screen, fence, NULL);
   }

   if (flags & ST_FLUSH_FRONT)
      st_manager_flush_frontbuffer(st);
}

/**
 * Replace the texture image of a texture object at the specified level.
 *
 * This is only for GLX_EXT_texture_from_pixmap and equivalent features
 * in EGL and WGL.
 */
bool
st_context_teximage(struct st_context *st, GLenum target,
                    int level, enum pipe_format pipe_format,
                    struct pipe_resource *tex, bool mipmap)
{
   struct gl_context *ctx = st->ctx;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLenum internalFormat;
   GLuint width, height, depth;

   texObj = _mesa_get_current_tex_object(ctx, target);

   _mesa_lock_texture(ctx, texObj);

   /* switch to surface based */
   if (!texObj->surface_based) {
      _mesa_clear_texture_object(ctx, texObj, NULL);
      texObj->surface_based = GL_TRUE;
   }

   texImage = _mesa_get_tex_image(ctx, texObj, target, level);
   if (tex) {
      mesa_format texFormat = st_pipe_format_to_mesa_format(pipe_format);

      if (util_format_has_alpha(tex->format))
         internalFormat = GL_RGBA;
      else
         internalFormat = GL_RGB;

      _mesa_init_teximage_fields(ctx, texImage,
                                 tex->width0, tex->height0, 1, 0,
                                 internalFormat, texFormat);

      width = tex->width0;
      height = tex->height0;
      depth = tex->depth0;

      /* grow the image size until we hit level = 0 */
      while (level > 0) {
         if (width != 1)
            width <<= 1;
         if (height != 1)
            height <<= 1;
         if (depth != 1)
            depth <<= 1;
         level--;
      }
   }
   else {
      _mesa_clear_texture_image(ctx, texImage);
      width = height = depth = 0;
   }
   _mesa_update_texture_object_swizzle(ctx, texObj);

   pipe_resource_reference(&texObj->pt, tex);
   st_texture_release_all_sampler_views(st, texObj);
   pipe_resource_reference(&texImage->pt, tex);
   texObj->surface_format = pipe_format;

   texObj->needs_validation = true;

   _mesa_dirty_texobj(ctx, texObj);
   ctx->Shared->HasExternallySharedImages = true;
   _mesa_unlock_texture(ctx, texObj);

   return true;
}


/**
 * Invalidate states to notify the frontend that driver states have been
 * changed behind its back.
 */
void
st_context_invalidate_state(struct st_context *st, unsigned flags)
{
   struct gl_context *ctx = st->ctx;

   if (flags & ST_INVALIDATE_FS_SAMPLER_VIEWS)
      ctx->NewDriverState |= ST_NEW_FS_SAMPLER_VIEWS;
   if (flags & ST_INVALIDATE_FS_CONSTBUF0)
      ctx->NewDriverState |= ST_NEW_FS_CONSTANTS;
   if (flags & ST_INVALIDATE_VS_CONSTBUF0)
      ctx->NewDriverState |= ST_NEW_VS_CONSTANTS;
   if (flags & ST_INVALIDATE_VERTEX_BUFFERS) {
      ctx->Array.NewVertexElements = true;
      ctx->NewDriverState |= ST_NEW_VERTEX_ARRAYS;
   }
   if (flags & ST_INVALIDATE_FB_STATE)
      ctx->NewDriverState |= ST_NEW_FB_STATE;
}


void
st_screen_destroy(struct pipe_frontend_screen *fscreen)
{
   struct st_screen *screen = fscreen->st_screen;

   if (screen && screen->drawable_ht) {
      _mesa_hash_table_destroy(screen->drawable_ht, NULL);
      simple_mtx_destroy(&screen->st_mutex);
      FREE(screen);
      fscreen->st_screen = NULL;
   }
}


/**
 * Create a rendering context.
 */
struct st_context *
st_api_create_context(struct pipe_frontend_screen *fscreen,
                      const struct st_context_attribs *attribs,
                      enum st_context_error *error,
                      struct st_context *shared_ctx)
{
   struct st_context *st;
   struct pipe_context *pipe;
   struct gl_config mode, *mode_ptr = &mode;
   bool no_error = false;

   _mesa_initialize(attribs->options.mesa_extension_override);

   /* Create a hash table for the framebuffer interface objects
    * if it has not been created for this st manager.
    */
   if (fscreen->st_screen == NULL) {
      struct st_screen *screen;

      screen = CALLOC_STRUCT(st_screen);
      simple_mtx_init(&screen->st_mutex, mtx_plain);

      /* We'll use drawable->ID as prehashed value to prevent the hash function
       * to get an existing drawable with a deleted drawable hash value when
       * doing lookups from st_framebuffers_purge and not dereference framebuffer
       * in time.
       */
      screen->drawable_ht = _mesa_hash_table_create(NULL,
                                                    NULL,
                                                    _mesa_key_pointer_equal);
      fscreen->st_screen = screen;
   }

   if (attribs->flags & ST_CONTEXT_FLAG_NO_ERROR)
      no_error = true;

   /* OpenGL ES 2.0+ does not support sampler state LOD bias. If we are creating
    * a GLES context, communicate that to the the driver to allow optimization.
    */
   bool is_gles = attribs->profile == API_OPENGLES2;
   unsigned lod_bias_flag = is_gles ? PIPE_CONTEXT_NO_LOD_BIAS : 0;

   pipe = fscreen->screen->context_create(fscreen->screen, NULL,
                                          PIPE_CONTEXT_PREFER_THREADED |
                                          lod_bias_flag |
                                          attribs->context_flags);
   if (!pipe) {
      *error = ST_CONTEXT_ERROR_NO_MEMORY;
      return NULL;
   }

   st_visual_to_context_mode(&attribs->visual, &mode);
   if (attribs->visual.color_format == PIPE_FORMAT_NONE)
      mode_ptr = NULL;
   st = st_create_context(attribs->profile, pipe, mode_ptr, shared_ctx,
                          &attribs->options, no_error,
                          !!fscreen->validate_egl_image);
   if (!st) {
      *error = ST_CONTEXT_ERROR_NO_MEMORY;
      pipe->destroy(pipe);
      return NULL;
   }

   if (attribs->flags & ST_CONTEXT_FLAG_DEBUG) {
      if (!_mesa_set_debug_state_int(st->ctx, GL_DEBUG_OUTPUT, GL_TRUE)) {
         *error = ST_CONTEXT_ERROR_NO_MEMORY;
         return NULL;
      }

      st->ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
   }

   if (st->ctx->Const.ContextFlags & GL_CONTEXT_FLAG_DEBUG_BIT) {
      _mesa_update_debug_callback(st->ctx);
   }

   if (attribs->flags & ST_CONTEXT_FLAG_FORWARD_COMPATIBLE)
      st->ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;

   if (attribs->context_flags & PIPE_CONTEXT_ROBUST_BUFFER_ACCESS) {
      st->ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_ROBUST_ACCESS_BIT_ARB;
      st->ctx->Const.RobustAccess = GL_TRUE;
   }

   if (attribs->context_flags & PIPE_CONTEXT_LOSE_CONTEXT_ON_RESET) {
      st->ctx->Const.ResetStrategy = GL_LOSE_CONTEXT_ON_RESET_ARB;
      st_install_device_reset_callback(st);
   }

   if (attribs->flags & ST_CONTEXT_FLAG_RELEASE_NONE)
       st->ctx->Const.ContextReleaseBehavior = GL_NONE;

   /* need to perform version check */
   if (attribs->major > 1 || attribs->minor > 0) {
      /* Is the actual version less than the requested version?
       */
      if (st->ctx->Version < attribs->major * 10U + attribs->minor) {
         *error = ST_CONTEXT_ERROR_BAD_VERSION;
         st_destroy_context(st);
         return NULL;
      }
   }

   st->can_scissor_clear = !!st->screen->caps.clear_scissored;

   st->ctx->invalidate_on_gl_viewport =
      fscreen->get_param(fscreen, ST_MANAGER_BROKEN_INVALIDATE);

   st->frontend_screen = fscreen;

   if (st->ctx->IntelBlackholeRender &&
       st->screen->caps.frontend_noop)
      st->pipe->set_frontend_noop(st->pipe, st->ctx->IntelBlackholeRender);

   *error = ST_CONTEXT_SUCCESS;
   return st;
}


/**
 * Get the currently bound context in the calling thread.
 */
struct st_context *
st_api_get_current(void)
{
   GET_CURRENT_CONTEXT(ctx);

   return ctx ? ctx->st : NULL;
}


static struct gl_framebuffer *
st_framebuffer_reuse_or_create(struct st_context *st,
                               struct pipe_frontend_drawable *drawable)
{
   struct gl_framebuffer *cur = NULL, *stfb = NULL;

   if (!drawable)
      return NULL;

   /* Check if there is already a framebuffer object for the specified
    * framebuffer interface in this context. If there is one, use it.
    */
   LIST_FOR_EACH_ENTRY(cur, &st->winsys_buffers, head) {
      if (cur->drawable_ID == drawable->ID) {
         _mesa_reference_framebuffer(&stfb, cur);
         break;
      }
   }

   /* If there is not already a framebuffer object, create one */
   if (stfb == NULL) {
      cur = st_framebuffer_create(st, drawable);

      if (cur) {
         /* add the referenced framebuffer interface object to
          * the framebuffer interface object hash table.
          */
         if (!drawable_insert(drawable->fscreen, drawable)) {
            _mesa_reference_framebuffer(&cur, NULL);
            return NULL;
         }

         /* add to the context's winsys buffers list */
         list_add(&cur->head, &st->winsys_buffers);

         _mesa_reference_framebuffer(&stfb, cur);
      }
   }

   return stfb;
}


/**
 * Bind the context to the calling thread with draw and read as drawables.
 *
 * The framebuffers might be NULL, meaning the context is surfaceless.
 */
bool
st_api_make_current(struct st_context *st,
                    struct pipe_frontend_drawable *stdrawi,
                    struct pipe_frontend_drawable *streadi)
{
   struct gl_framebuffer *stdraw, *stread;
   bool ret;

   if (st) {
      /* reuse or create the draw fb */
      stdraw = st_framebuffer_reuse_or_create(st, stdrawi);
      if (streadi != stdrawi) {
         /* do the same for the read fb */
         stread = st_framebuffer_reuse_or_create(st, streadi);
      }
      else {
         stread = NULL;
         /* reuse the draw fb for the read fb */
         if (stdraw)
            _mesa_reference_framebuffer(&stread, stdraw);
      }

      /* If framebuffers were asked for, we'd better have allocated them */
      if ((stdrawi && !stdraw) || (streadi && !stread))
         return false;

      if (stdraw && stread) {
         st_framebuffer_validate(stdraw, st);
         if (stread != stdraw)
            st_framebuffer_validate(stread, st);

         ret = _mesa_make_current(st->ctx, stdraw, stread);

         st->draw_stamp = stdraw->stamp - 1;
         st->read_stamp = stread->stamp - 1;
         st_context_validate(st, stdraw, stread);
      }
      else {
         struct gl_framebuffer *incomplete = _mesa_get_incomplete_framebuffer();
         ret = _mesa_make_current(st->ctx, incomplete, incomplete);
      }

      _mesa_reference_framebuffer(&stdraw, NULL);
      _mesa_reference_framebuffer(&stread, NULL);

      /* Purge the context's winsys_buffers list in case any
       * of the referenced drawables no longer exist.
       */
      st_framebuffers_purge(st);
   }
   else {
      GET_CURRENT_CONTEXT(ctx);

      if (ctx) {
         /* Before releasing the context, release its associated
          * winsys buffers first. Then purge the context's winsys buffers list
          * to free the resources of any winsys buffers that no longer have
          * an existing drawable.
          */
         ret = _mesa_make_current(ctx, NULL, NULL);
         st_framebuffers_purge(ctx->st);
      }

      ret = _mesa_make_current(NULL, NULL, NULL);
   }

   return ret;
}


/**
 * Flush the front buffer if the current context renders to the front buffer.
 */
void
st_manager_flush_frontbuffer(struct st_context *st)
{
   struct gl_framebuffer *stfb = st_ws_framebuffer(st->ctx->DrawBuffer);
   struct gl_renderbuffer *rb = NULL;

   if (!stfb)
      return;

   /* If the context uses a doublebuffered visual, but the buffer is
    * single-buffered, guess that it's a pbuffer, which doesn't need
    * flushing.
    */
   if (st->ctx->Visual.doubleBufferMode &&
       !stfb->Visual.doubleBufferMode)
      return;

   /* Check front buffer used at the GL API level. */
   enum st_attachment_type statt = ST_ATTACHMENT_FRONT_LEFT;
   rb = stfb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer;
   if (!rb) {
       /* Check back buffer redirected by EGL_KHR_mutable_render_buffer. */
       statt = ST_ATTACHMENT_BACK_LEFT;
       rb = stfb->Attachment[BUFFER_BACK_LEFT].Renderbuffer;
   }

   /* Do we have a front color buffer and has it been drawn to since last
    * frontbuffer flush?
    */
   if (rb && rb->defined &&
       stfb->drawable->flush_front(st, stfb->drawable, statt)) {
      rb->defined = GL_FALSE;

      /* Trigger an update of rb->defined on next draw */
      st->ctx->NewDriverState |= ST_NEW_FB_STATE;
   }
}


/**
 * Re-validate the framebuffers.
 */
void
st_manager_validate_framebuffers(struct st_context *st)
{
   struct gl_framebuffer *stdraw = st_ws_framebuffer(st->ctx->DrawBuffer);
   struct gl_framebuffer *stread = st_ws_framebuffer(st->ctx->ReadBuffer);

   if (stdraw)
      st_framebuffer_validate(stdraw, st);
   if (stread && stread != stdraw)
      st_framebuffer_validate(stread, st);

   st_context_validate(st, stdraw, stread);
}


/**
 * Flush any outstanding swapbuffers on the current draw framebuffer.
 */
void
st_manager_flush_swapbuffers(void)
{
   GET_CURRENT_CONTEXT(ctx);
   struct st_context *st = (ctx) ? ctx->st : NULL;
   struct gl_framebuffer *stfb;

   if (!st)
      return;

   stfb = st_ws_framebuffer(ctx->DrawBuffer);
   if (!stfb || !stfb->drawable->flush_swapbuffers)
      return;

   stfb->drawable->flush_swapbuffers(st, stfb->drawable);
}


/**
 * Add a color renderbuffer on demand.  The FBO must correspond to a window,
 * not a user-created FBO.
 */
bool
st_manager_add_color_renderbuffer(struct gl_context *ctx,
                                  struct gl_framebuffer *fb,
                                  gl_buffer_index idx)
{
   struct gl_framebuffer *stfb = st_ws_framebuffer(fb);

   /* FBO */
   if (!stfb)
      return false;

   assert(_mesa_is_winsys_fbo(fb));

   if (stfb->Attachment[idx].Renderbuffer)
      return true;

   switch (idx) {
   case BUFFER_FRONT_LEFT:
   case BUFFER_BACK_LEFT:
   case BUFFER_FRONT_RIGHT:
   case BUFFER_BACK_RIGHT:
      break;
   default:
      return false;
   }

   if (!st_framebuffer_add_renderbuffer(stfb, idx,
                                        stfb->Visual.sRGBCapable))
      return false;

   st_framebuffer_update_attachments(stfb);

   /*
    * Force a call to the frontend manager to validate the
    * new renderbuffer. It might be that there is a window system
    * renderbuffer available.
    */
   if (stfb->drawable)
      stfb->drawable_stamp = p_atomic_read(&stfb->drawable->stamp) - 1;

   st_invalidate_buffers(st_context(ctx));

   return true;
}


static unsigned
get_version(struct pipe_screen *screen,
            struct st_config_options *options, gl_api api)
{
   struct gl_constants consts = {0};
   struct gl_extensions extensions = {0};
   GLuint version;

   if (_mesa_override_gl_version_contextless(&consts, &api, &version)) {
      return version;
   }

   _mesa_init_constants(&consts, api);
   _mesa_init_extensions(&extensions);

   st_init_limits(screen, &consts, &extensions, api);
   st_init_extensions(screen, &consts, &extensions, options, api);
   version = _mesa_get_version(&extensions, &consts, api);
   free(consts.SpirVExtensions);
   return version;
}


/**
 * Query supported OpenGL versions. (if applicable)
 * The format is (major*10+minor).
 */
void
st_api_query_versions(struct pipe_frontend_screen *fscreen,
                      struct st_config_options *options,
                      int *gl_core_version,
                      int *gl_compat_version,
                      int *gl_es1_version,
                      int *gl_es2_version)
{
   *gl_core_version = get_version(fscreen->screen, options, API_OPENGL_CORE);
   *gl_compat_version = get_version(fscreen->screen, options, API_OPENGL_COMPAT);
   *gl_es1_version = get_version(fscreen->screen, options, API_OPENGLES);
   *gl_es2_version = get_version(fscreen->screen, options, API_OPENGLES2);
}


void
st_manager_invalidate_drawables(struct gl_context *ctx)
{
   struct gl_framebuffer *stdraw;
   struct gl_framebuffer *stread;

   /*
    * Normally we'd want the frontend manager to mark the drawables
    * invalid only when needed. This will force the frontend manager
    * to revalidate the drawable, rather than just update the context with
    * the latest cached drawable info.
    */

   stdraw = st_ws_framebuffer(ctx->DrawBuffer);
   stread = st_ws_framebuffer(ctx->ReadBuffer);

   if (stdraw)
      stdraw->drawable_stamp = p_atomic_read(&stdraw->drawable->stamp) - 1;
   if (stread && stread != stdraw)
      stread->drawable_stamp = p_atomic_read(&stread->drawable->stamp) - 1;
}