sync with latest EGL_MESA_screen_surface spec (EGLScreenMESA handles)

13 files changed, 285 insertions, 119 deletions

diff --git a/src/egl/drivers/demo/demo.c b/src/egl/drivers/demo/demo.c
index 041884b40a0..e5164d657f7 100644
--- a/src/egl/drivers/demo/demo.c
+++ b/src/egl/drivers/demo/demo.c
@@ -55,51 +55,34 @@ demoInitialize(_EGLDriver *drv, EGLDisplay dpy, EGLint *major, EGLint *minor)
    _EGLScreen *scrn;
    EGLint i;
 
-   disp->NumScreens = 1;
-   disp->Screens = (_EGLScreen *) calloc(disp->NumScreens, sizeof(_EGLScreen));
-   scrn = disp->Screens + 0;
-   scrn->NumModes = 4;
-   scrn->Modes = (_EGLMode *) calloc(scrn->NumModes, sizeof(_EGLMode));
-   scrn->Modes[0].Width = 1600;
-   scrn->Modes[0].Height = 1200;
-   scrn->Modes[0].Depth = 32;
-   scrn->Modes[0].RefreshRate = 72 * 1000;
-   scrn->Modes[1].Width = 1280;
-   scrn->Modes[1].Height = 1024;
-   scrn->Modes[1].Depth = 32;
-   scrn->Modes[1].RefreshRate = 72 * 1000;
-   scrn->Modes[2].Width = 1280;
-   scrn->Modes[2].Height = 1024;
-   scrn->Modes[2].Depth = 16;
-   scrn->Modes[2].RefreshRate = 72 * 1000;
-   scrn->Modes[3].Width = 1024;
-   scrn->Modes[3].Height = 768;
-   scrn->Modes[3].Depth = 16;
-   scrn->Modes[3].RefreshRate = 72 * 1000;
-   for (i = 0; i < scrn->NumModes; i++)
-      scrn->Modes[i].Handle = i + 1;
-
-   /* Create list of visual configs - this is a silly example */
-   disp->NumConfigs = 4;
-   disp->Configs = (_EGLConfig *) calloc(disp->NumConfigs, sizeof(_EGLConfig));
-   for (i = 0; i < disp->NumConfigs; i++) {
-      _EGLConfig *config = disp->Configs + i;
-      _eglInitConfig(config, i + 1);
-      SET_CONFIG_ATTRIB(config, EGL_RED_SIZE, 8);
-      SET_CONFIG_ATTRIB(config, EGL_GREEN_SIZE, 8);
-      SET_CONFIG_ATTRIB(config, EGL_BLUE_SIZE, 8);
-      SET_CONFIG_ATTRIB(config, EGL_ALPHA_SIZE, 8);
-      SET_CONFIG_ATTRIB(config, EGL_BUFFER_SIZE, 32);
-
+   /* Create a screen */
+   scrn = _eglNewScreen();
+   _eglAddScreen(disp, scrn);
+
+   /* Create the screen's modes - silly example */
+   _eglAddMode(scrn, 1600, 1200, 32, 72 * 1000);
+   _eglAddMode(scrn, 1280, 1024, 32, 72 * 1000);
+   _eglAddMode(scrn, 1280, 1024, 16, 72 * 1000);
+   _eglAddMode(scrn, 1024,  768, 32, 72 * 1000);
+
+   /* Create the display's visual configs - silly example */
+   for (i = 0; i < 4; i++) {
+      _EGLConfig config;
+      _eglInitConfig(&config, i + 1);
+      SET_CONFIG_ATTRIB(&config, EGL_RED_SIZE, 8);
+      SET_CONFIG_ATTRIB(&config, EGL_GREEN_SIZE, 8);
+      SET_CONFIG_ATTRIB(&config, EGL_BLUE_SIZE, 8);
+      SET_CONFIG_ATTRIB(&config, EGL_ALPHA_SIZE, 8);
+      SET_CONFIG_ATTRIB(&config, EGL_BUFFER_SIZE, 32);
       if (i & 1) {
-         SET_CONFIG_ATTRIB(config, EGL_DEPTH_SIZE, 32);
+         SET_CONFIG_ATTRIB(&config, EGL_DEPTH_SIZE, 32);
       }
       if (i & 2) {
-         SET_CONFIG_ATTRIB(config, EGL_STENCIL_SIZE, 8);
+         SET_CONFIG_ATTRIB(&config, EGL_STENCIL_SIZE, 8);
       }
-
-      SET_CONFIG_ATTRIB(config, EGL_SURFACE_TYPE,
+      SET_CONFIG_ATTRIB(&config, EGL_SURFACE_TYPE,
                         (EGL_WINDOW_BIT | EGL_PIXMAP_BIT | EGL_PBUFFER_BIT));
+      _eglAddConfig(disp, &config);
    }
 
    drv->Initialized = EGL_TRUE;
diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index d9c8845aa49..b0bd1eed6cf 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -370,24 +370,24 @@ void (* APIENTRY eglGetProcAddress(const char *procname))()
  */
 
 EGLBoolean APIENTRY
-eglChooseModeMESA(EGLDisplay dpy, EGLint screen_number,
+eglChooseModeMESA(EGLDisplay dpy, EGLScreenMESA screen,
                   const EGLint *attrib_list, EGLModeMESA *modes,
                   EGLint modes_size, EGLint *num_modes)
 {
    _EGLDriver *drv = _eglLookupDriver(dpy);
    if (drv)
-      return drv->ChooseModeMESA(drv, dpy, screen_number, attrib_list, modes, modes_size, num_modes);
+      return drv->ChooseModeMESA(drv, dpy, screen, attrib_list, modes, modes_size, num_modes);
    else
       return EGL_FALSE;
 }
 
 
 EGLBoolean APIENTRY
-eglGetModesMESA(EGLDisplay dpy, EGLint screen_number, EGLModeMESA *modes, EGLint mode_size, EGLint *num_mode)
+eglGetModesMESA(EGLDisplay dpy, EGLScreenMESA screen, EGLModeMESA *modes, EGLint mode_size, EGLint *num_mode)
 {
    _EGLDriver *drv = _eglLookupDriver(dpy);
    if (drv)
-      return drv->GetModesMESA(drv, dpy, screen_number, modes, mode_size, num_mode);
+      return drv->GetModesMESA(drv, dpy, screen, modes, mode_size, num_mode);
    else
       return EGL_FALSE;
 }
@@ -404,57 +404,47 @@ eglGetModeAttribMESA(EGLDisplay dpy, EGLModeMESA mode, EGLint attribute, EGLint
 }
 
 
-EGLSurface
-eglCreateScreenSurfaceMESA(EGLDisplay dpy, EGLConfig config, const EGLint *attrib_list)
-{
-   return EGL_FALSE;
-}
-
-
 EGLBoolean
-eglShowSurfaceMESA(EGLDisplay dpy, EGLint screen, EGLSurface surface)
+eglGetScreensMESA(EGLDisplay dpy, EGLScreenMESA *screens, EGLint max_screens, EGLint *num_screens)
 {
-   return EGL_FALSE;
-}
-
-
-EGLBoolean
-eglScreenModeMESA(EGLDisplay dpy, EGLint screen_number, EGLModeMESA mode)
-{
-   return EGL_FALSE;
+   _EGLDriver *drv = _eglLookupDriver(dpy);
+   if (drv)
+      return drv->GetScreensMESA(drv, dpy, screens, max_screens, num_screens);
+   else
+      return EGL_FALSE;
 }
 
 
-EGLBoolean
-eglScreenAttribsMESA(EGLDisplay dpy, EGLint screen, const EGLint *attrib_list)
+EGLSurface
+eglCreateScreenSurfaceMESA(EGLDisplay dpy, EGLConfig config, const EGLint *attrib_list)
 {
    return EGL_FALSE;
 }
 
 
 EGLBoolean
-eglQueryDisplayMESA(EGLDisplay dpy, EGLint attribute, EGLint *value)
+eglShowSurfaceMESA(EGLDisplay dpy, EGLint screen, EGLSurface surface)
 {
    return EGL_FALSE;
 }
 
 
 EGLBoolean
-eglQueryScreenSurfaceMESA(EGLDisplay dpy, EGLint screen_number, EGLSurface *surface)
+eglScreenModeMESA(EGLDisplay dpy, EGLScreenMESA screen, EGLModeMESA mode)
 {
    return EGL_FALSE;
 }
 
 
 EGLBoolean
-eglQueryScreenModeMESA(EGLDisplay dpy, EGLint screen_number, EGLModeMESA *mode)
+eglQueryScreenSurfaceMESA(EGLDisplay dpy, EGLScreenMESA screen, EGLSurface *surface)
 {
    return EGL_FALSE;
 }
 
 
 EGLBoolean
-eglQueryScreenMESA( EGLDisplay dpy, EGLint screen_number, EGLint attribute, EGLint *value)
+eglQueryScreenMESA( EGLDisplay dpy, EGLScreenMESA screen, EGLint attribute, EGLint *value)
 {
    return EGL_FALSE;
 }
diff --git a/src/egl/main/eglconfig.c b/src/egl/main/eglconfig.c
index 765e2e3dbeb..0fb7e260723 100644
--- a/src/egl/main/eglconfig.c
+++ b/src/egl/main/eglconfig.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 #include "eglconfig.h"
@@ -51,6 +52,31 @@ _eglLookupConfig(_EGLDriver *drv, EGLDisplay dpy, EGLConfig config)
 }
 
 
+/**
+ * Add the given _EGLConifg to the given display.
+ */
+_EGLConfig *
+_eglAddConfig(_EGLDisplay *display, const _EGLConfig *config)
+{
+   _EGLConfig *newConfigs;
+   EGLint n;
+
+   n = display->NumConfigs;
+
+   newConfigs = (_EGLConfig *) realloc(display->Configs,
+                                       (n + 1) * sizeof(_EGLConfig));
+   if (newConfigs) {
+      display->Configs = newConfigs;
+      display->Configs[n] = *config; /* copy struct */
+      display->NumConfigs++;
+      return display->Configs + n;
+   }
+   else {
+      return NULL;
+   }
+}
+
+
 
 /**
  * Parse the attrib_list to fill in the fields of the given _egl_config
diff --git a/src/egl/main/eglconfig.h b/src/egl/main/eglconfig.h
index 0bd0ce650a9..874edcdfb6f 100644
--- a/src/egl/main/eglconfig.h
+++ b/src/egl/main/eglconfig.h
@@ -29,6 +29,10 @@ extern _EGLConfig *
 _eglLookupConfig(_EGLDriver *drv, EGLDisplay dpy, EGLConfig config);
 
 
+extern _EGLConfig *
+_eglAddConfig(_EGLDisplay *display, const _EGLConfig *config);
+
+
 extern EGLBoolean
 _eglParseConfigAttribs(_EGLConfig *config, const EGLint *attrib_list);
 
diff --git a/src/egl/main/egldisplay.h b/src/egl/main/egldisplay.h
index a2831e65a46..55555e67d8a 100644
--- a/src/egl/main/egldisplay.h
+++ b/src/egl/main/egldisplay.h
@@ -13,7 +13,7 @@ struct _egl_display
    _EGLDriver *Driver;
 
    EGLint NumScreens;
-   _EGLScreen *Screens;  /* array [NumScreens] */
+   _EGLScreen **Screens;  /* array [NumScreens] */
 
    EGLint NumConfigs;
    _EGLConfig *Configs;  /* array [NumConfigs] */
diff --git a/src/egl/main/egldriver.c b/src/egl/main/egldriver.c
index 5b65b80ea4b..870c06205c6 100644
--- a/src/egl/main/egldriver.c
+++ b/src/egl/main/egldriver.c
@@ -8,6 +8,7 @@
 #include "egldriver.h"
 #include "eglglobals.h"
 #include "eglmode.h"
+#include "eglscreen.h"
 #include "eglsurface.h"
 
 
@@ -181,8 +182,16 @@ _eglInitDriverFallbacks(_EGLDriver *drv)
    drv->WaitNative = _eglWaitNative;
 
    /* EGL_MESA_screen */
+   drv->ChooseModeMESA = _eglChooseModeMESA; 
    drv->GetModesMESA = _eglGetModesMESA;
    drv->GetModeAttribMESA = _eglGetModeAttribMESA;
+   drv->GetScreensMESA = _eglGetScreensMESA;
+   drv->CreateScreenSurfaceMESA = _eglCreateScreenSurfaceMESA;
+   drv->ShowSurfaceMESA = _eglShowSurfaceMESA;
+   drv->ScreenPositionMESA = _eglScreenPositionMESA;
+   drv->QueryScreenMESA = _eglQueryScreenMESA;
+   drv->QueryScreenSurfaceMESA = _eglQueryScreenSurfaceMESA;
+   drv->QueryScreenModeMESA = _eglQueryScreenModeMESA;
 }
 
 
diff --git a/src/egl/main/egldriver.h b/src/egl/main/egldriver.h
index 4ced7941d36..e93155967d6 100644
--- a/src/egl/main/egldriver.h
+++ b/src/egl/main/egldriver.h
@@ -40,10 +40,16 @@ typedef EGLBoolean (*WaitNative_t)(_EGLDriver *drv, EGLDisplay dpy, EGLint engin
 
 
 /* EGL_MESA_screen extension */
-typedef EGLBoolean (*ChooseModeMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number, const EGLint *attrib_list, EGLModeMESA *modes, EGLint modes_size, EGLint *num_modes);
-typedef EGLBoolean (*GetModesMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number, EGLModeMESA *modes, EGLint mode_size, EGLint *num_mode);
+typedef EGLBoolean (*ChooseModeMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, const EGLint *attrib_list, EGLModeMESA *modes, EGLint modes_size, EGLint *num_modes);
+typedef EGLBoolean (*GetModesMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLModeMESA *modes, EGLint mode_size, EGLint *num_mode);
 typedef EGLBoolean (*GetModeAttribMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLModeMESA mode, EGLint attribute, EGLint *value);
-
+typedef EGLBoolean (*GetScreensMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA *screens, EGLint max_screens, EGLint *num_screens);
+typedef EGLSurface (*CreateScreenSurfaceMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLConfig config, const EGLint *attrib_list);
+typedef EGLBoolean (*ShowSurfaceMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLSurface surface);
+typedef EGLBoolean (*ScreenPositionMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLint x, EGLint y);
+typedef EGLBoolean (*QueryScreenMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLint attribute, EGLint *value);
+typedef EGLBoolean (*QueryScreenSurfaceMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLSurface *surface);
+typedef EGLBoolean (*QueryScreenModeMESA_t)(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLModeMESA *mode);
 
 
 
@@ -96,6 +102,13 @@ struct _egl_driver
    ChooseModeMESA_t ChooseModeMESA;
    GetModesMESA_t GetModesMESA;
    GetModeAttribMESA_t GetModeAttribMESA;
+   GetScreensMESA_t GetScreensMESA;
+   CreateScreenSurfaceMESA_t CreateScreenSurfaceMESA;
+   ShowSurfaceMESA_t ShowSurfaceMESA;
+   ScreenPositionMESA_t ScreenPositionMESA;
+   QueryScreenMESA_t QueryScreenMESA;
+   QueryScreenSurfaceMESA_t QueryScreenSurfaceMESA;
+   QueryScreenModeMESA_t QueryScreenModeMESA;
 };
 
 
diff --git a/src/egl/main/eglglobals.c b/src/egl/main/eglglobals.c
index 102e5506206..6265b07529a 100644
--- a/src/egl/main/eglglobals.c
+++ b/src/egl/main/eglglobals.c
@@ -16,6 +16,7 @@ _eglInitGlobals(void)
       _eglGlobal.Displays = _eglNewHashTable();
       _eglGlobal.Contexts = _eglNewHashTable();
       _eglGlobal.Surfaces = _eglNewHashTable();
+      _eglGlobal.FreeScreenHandle = 1;
       _eglGlobal.CurrentContext = EGL_NO_CONTEXT;
       _eglGlobal.LastError = EGL_SUCCESS;
       _eglGlobal.Initialized = EGL_TRUE;
@@ -49,3 +50,16 @@ _eglError(EGLint errCode, const char *msg)
       fprintf(stderr, "EGL Error 0x%x in %s\n", errCode, msg);
    }
 }
+
+
+/**
+ * Return a new screen handle/ID.
+ * NOTE: we never reuse these!
+ */
+EGLScreenMESA
+_eglAllocScreenHandle(void)
+{
+   EGLScreenMESA s = _eglGlobal.FreeScreenHandle;
+   _eglGlobal.FreeScreenHandle++;
+   return s;
+}
diff --git a/src/egl/main/eglglobals.h b/src/egl/main/eglglobals.h
index fbf2813f7ae..1a6f12d174e 100644
--- a/src/egl/main/eglglobals.h
+++ b/src/egl/main/eglglobals.h
@@ -13,6 +13,8 @@ struct _egl_global
    _EGLHashtable *Contexts;
    _EGLHashtable *Surfaces;
 
+   EGLScreenMESA FreeScreenHandle;
+
    EGLint LastError;
 
    /* XXX this should be per-thread someday */
@@ -35,4 +37,8 @@ extern void
 _eglError(EGLint errCode, const char *msg);
 
 
+extern EGLScreenMESA
+_eglAllocScreenHandle(void);
+
+
 #endif /* EGLGLOBALS_INCLUDED */
diff --git a/src/egl/main/eglmode.c b/src/egl/main/eglmode.c
index 201ddb17f71..857fa380c6e 100644
--- a/src/egl/main/eglmode.c
+++ b/src/egl/main/eglmode.c
@@ -1,3 +1,5 @@
+#include <assert.h>
+#include <stdlib.h>
 #include "egldisplay.h"
 #include "egldriver.h"
 #include "eglmode.h"
@@ -8,30 +10,76 @@
 #define MIN2(A, B)  (((A) < (B)) ? (A) : (B))
 
 
+/**
+ * Given an EGLModeMESA handle, return the corresponding _EGLMode object
+ * or null if non-existant.
+ */
 _EGLMode *
 _eglLookupMode(EGLDisplay dpy, EGLModeMESA mode)
 {
    const _EGLDisplay *disp = _eglLookupDisplay(dpy);
    EGLint scrnum;
 
+   /* loop over all screens on the display */
    for (scrnum = 0; scrnum < disp->NumScreens; scrnum++) {
-      const _EGLScreen *scrn = disp->Screens + scrnum;
+      const _EGLScreen *scrn = disp->Screens[scrnum];
       EGLint i;
+      /* search list of modes for handle */
       for (i = 0; i < scrn->NumModes; i++) {
          if (scrn->Modes[i].Handle == mode) {
             return scrn->Modes + i;
          }
       }
    }
+
    return NULL;
 }
 
 
 /**
+ * Add a new mode with the given attributes (width, height, depth, refreshRate)
+ * to the given screen.
+ * Assign a new mode ID/handle to the mode as well.
+ * \return pointer to the new _EGLMode
+ */
+_EGLMode *
+_eglAddMode(_EGLScreen *screen, EGLint width, EGLint height,
+            EGLint depth, EGLint refreshRate)
+{
+   EGLint n;
+   _EGLMode *newModes;
+
+   assert(screen);
+   assert(width > 0);
+   assert(height > 0);
+   assert(depth > 0);
+   assert(refreshRate > 0);
+
+   n = screen->NumModes;
+   newModes = (_EGLMode *) realloc(screen->Modes, (n+1) * sizeof(_EGLMode));
+   if (newModes) {
+      screen->Modes = newModes;
+      screen->Modes[n].Handle = n + 1;
+      screen->Modes[n].Width = width;
+      screen->Modes[n].Height = height;
+      screen->Modes[n].Depth = depth;
+      screen->Modes[n].RefreshRate = refreshRate;
+      screen->Modes[n].Stereo = EGL_FALSE;
+      screen->NumModes++;
+      return screen->Modes + n;
+   }
+   else {
+      return NULL;
+   }
+}
+
+
+
+/**
  * Search for the EGLMode that best matches the given attribute list.
  */
 EGLBoolean
-_eglChooseModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglChooseModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                    const EGLint *attrib_list, EGLModeMESA *modes,
                    EGLint modes_size, EGLint *num_modes)
 {
@@ -70,10 +118,10 @@ _eglChooseModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
  * Return all possible modes for the given screen
  */
 EGLBoolean
-_eglGetModesMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglGetModesMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                  EGLModeMESA *modes, EGLint modes_size, EGLint *num_modes)
 {
-   _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
    EGLint i;
 
    if (!scrn) {
diff --git a/src/egl/main/eglmode.h b/src/egl/main/eglmode.h
index b3c268d1fb2..fa6d8e48fc1 100644
--- a/src/egl/main/eglmode.h
+++ b/src/egl/main/eglmode.h
@@ -3,9 +3,13 @@
 
 #include "egltypedefs.h"
 
+
+/**
+ * Data structure which corresponds to an EGLModeMESA.
+ */
 struct _egl_mode
 {
-   EGLConfig Handle;       /* the public/opaque handle which names this mode */
+   EGLModeMESA Handle;     /* the public/opaque handle which names this mode */
    EGLint Width, Height;   /* size in pixels */
    EGLint Depth;           /* bits per pixel */
    EGLint RefreshRate;     /* rate * 1000.0 */
@@ -21,14 +25,19 @@ extern _EGLMode *
 _eglLookupMode(EGLDisplay dpy, EGLModeMESA mode);
 
 
+extern _EGLMode *
+_eglAddMode(_EGLScreen *screen, EGLint width, EGLint height,
+            EGLint depth, EGLint refreshRate);
+
+
 extern EGLBoolean
-_eglChooseModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglChooseModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                    const EGLint *attrib_list, EGLModeMESA *modes,
                    EGLint modes_size, EGLint *num_modes);
 
 
 extern EGLBoolean
-_eglGetModesMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglGetModesMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                  EGLModeMESA *modes, EGLint modes_size, EGLint *num_modes);
 
 
diff --git a/src/egl/main/eglscreen.c b/src/egl/main/eglscreen.c
index c3c1a479847..66baa319529 100644
--- a/src/egl/main/eglscreen.c
+++ b/src/egl/main/eglscreen.c
@@ -2,14 +2,13 @@
  * Ideas for screen management extension to EGL.
  *
  * Each EGLDisplay has one or more screens (CRTs, Flat Panels, etc).
- * The number of screens can be queried with eglQueryDisplay(EGL_SCREEN_COUNT).
+ * The screens' handles can be obtained with eglGetScreensMESA().
  *
  * A new kind of EGLSurface is possible- one which can be directly scanned
  * out on a screen.  Such a surface is created with eglCreateScreenSurface().
  *
  * To actually display a screen surface on a screen, the eglShowSurface()
  * function is called.
- *
  */
 
 #include <assert.h>
@@ -21,16 +20,84 @@
 #include "eglscreen.h"
 
 
+/**
+ * Return a new _EGLScreen object.
+ */
+_EGLScreen *
+_eglNewScreen(void)
+{
+   return (_EGLScreen *) calloc(1, sizeof(_EGLScreen));
+}
+
+
+/**
+ * Given a public screen handle, return the internal _EGLScreen object.
+ */
 _EGLScreen *
-_eglLookupScreen(EGLDisplay dpy, GLint screenNumber)
+_eglLookupScreen(EGLDisplay dpy, EGLScreenMESA screen)
 {
-   _EGLDisplay *disp = _eglLookupDisplay(dpy);
-   if (!disp || screenNumber < 0 || screenNumber >= disp->NumScreens) {
+   EGLint i;
+   _EGLDisplay *display = _eglLookupDisplay(dpy);
+
+   if (!display)
       return NULL;
+
+   for (i = 0; i < display->NumScreens; i++) {
+      if (display->Screens[i]->Handle == screen)
+         return display->Screens[i];
+   }
+   return NULL;
+}
+
+
+/**
+ * Add the given _EGLScreen to the display's list of screens.
+ */
+void
+_eglAddScreen(_EGLDisplay *display, _EGLScreen *screen)
+{
+   EGLint n;
+
+   assert(display);
+   assert(screen);
+
+   screen->Handle = _eglAllocScreenHandle();
+   n = display->NumScreens;
+   display->Screens = realloc(display->Screens, (n+1) * sizeof(_EGLScreen *));
+   display->Screens[n] = screen;
+   display->NumScreens++;
+}
+
+
+
+EGLBoolean
+_eglGetScreensMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA *screens,
+                   EGLint max_screens, EGLint *num_screens)
+{
+   _EGLDisplay *display = _eglLookupDisplay(dpy);
+   EGLint n;
+
+   if (!display) {
+      _eglError(EGL_BAD_DISPLAY, "eglGetScreensMESA");
+      return EGL_FALSE;
+   }
+
+   if (display->NumScreens > max_screens) {
+      n = max_screens;
    }
    else {
-      return disp->Screens + screenNumber;
+      n = display->NumScreens;
    }
+
+   if (screens) {
+      EGLint i;
+      for (i = 0; i < n; i++)
+         screens[i] = display->Screens[i]->Handle;
+   }
+   if (num_screens)
+      *num_screens = n;
+
+   return EGL_TRUE;
 }
 
 
@@ -87,10 +154,10 @@ _eglCreateScreenSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLConfig config,
  * this with code that _really_ shows the surface.
  */
 EGLBoolean
-_eglShowSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglShowSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                     EGLSurface surface)
 {
-   _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
    _EGLMode *mode;
 
    if (!scrn) {
@@ -139,10 +206,10 @@ _eglShowSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
  * this with code that _really_ sets the mode.
  */
 EGLBoolean
-_eglScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                    EGLModeMESA mode)
 {
-   _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
 
    if (!scrn) {
       _eglError(EGL_BAD_SCREEN_MESA, "eglScreenModeMESA");
@@ -160,9 +227,9 @@ _eglScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
  */
 EGLBoolean
 _eglScreenPositionMESA(_EGLDriver *drv, EGLDisplay dpy,
-                       EGLint screen_number, EGLint x, EGLint y)
+                       EGLScreenMESA screen, EGLint x, EGLint y)
 {
-   _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
    if (!scrn) {
       _eglError(EGL_BAD_SCREEN_MESA, "eglScreenPositionMESA");
       return EGL_FALSE;
@@ -175,31 +242,14 @@ _eglScreenPositionMESA(_EGLDriver *drv, EGLDisplay dpy,
 }
 
 
-EGLBoolean
-_eglQueryDisplayMESA(_EGLDriver *drv, EGLDisplay dpy,
-                     EGLint attribute, EGLint *value)
-{
-   const _EGLDisplay *display = _eglLookupDisplay(dpy);
-   switch (attribute) {
-   case EGL_SCREEN_COUNT_MESA:
-      *value = display->NumScreens;
-      break;
-   default:
-      _eglError(EGL_BAD_ATTRIBUTE, "eglQueryDisplayMESA");
-      return EGL_FALSE;
-   }
-   return EGL_TRUE;
-}
-
-
 /**
  * Query a screen's current surface.
  */
 EGLBoolean
 _eglQueryScreenSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy,
-                           EGLint screen_number, EGLSurface *surface)
+                           EGLScreenMESA screen, EGLSurface *surface)
 {
-   const _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   const _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
    if (scrn->CurrentSurface)
       *surface = scrn->CurrentSurface->Handle;
    else
@@ -212,10 +262,10 @@ _eglQueryScreenSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy,
  * Query a screen's current mode.
  */
 EGLBoolean
-_eglQueryScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglQueryScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                         EGLModeMESA *mode)
 {
-   const _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   const _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
    if (scrn->CurrentMode)
       *mode = scrn->CurrentMode->Handle;
    else
@@ -225,10 +275,10 @@ _eglQueryScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
 
 
 EGLBoolean
-_eglQueryScreenMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number,
+_eglQueryScreenMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen,
                     EGLint attribute, EGLint *value)
 {
-   const _EGLScreen *scrn = _eglLookupScreen(dpy, screen_number);
+   const _EGLScreen *scrn = _eglLookupScreen(dpy, screen);
 
    if (!scrn) {
       _eglError(EGL_BAD_SCREEN_MESA, "eglQueryScreenMESA");
diff --git a/src/egl/main/eglscreen.h b/src/egl/main/eglscreen.h
index 1dbb766dc69..1d1856b96b7 100644
--- a/src/egl/main/eglscreen.h
+++ b/src/egl/main/eglscreen.h
@@ -8,6 +8,8 @@
 
 struct _egl_screen
 {
+   EGLScreenMESA Handle; /* The public/opaque handle which names this object */
+
    _EGLMode *CurrentMode;
    _EGLSurface *CurrentSurface;
    EGLint OriginX, OriginY;
@@ -18,7 +20,19 @@ struct _egl_screen
 
 
 extern _EGLScreen *
-_eglLookupScreen(EGLDisplay dpy, GLint screenNumber);
+_eglNewScreen(void);
+
+
+extern _EGLScreen *
+_eglLookupScreen(EGLDisplay dpy, EGLScreenMESA screen);
+
+
+extern void
+_eglAddScreen(_EGLDisplay *display, _EGLScreen *screen);
+
+
+extern EGLBoolean
+_eglGetScreensMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA *screens, EGLint max_screens, EGLint *num_screens);
 
 
 extern EGLSurface
@@ -26,15 +40,15 @@ _eglCreateScreenSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLConfig config, c
 
 
 extern EGLBoolean
-_eglShowSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen, EGLSurface surface);
+_eglShowSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLSurface surface);
 
 
 extern EGLBoolean
-_eglScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number, EGLModeMESA mode);
+_eglScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLModeMESA mode);
 
 
 extern EGLBoolean
-_eglScreenPositionMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number, EGLint x, EGLint y);
+_eglScreenPositionMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLint x, EGLint y);
 
 
 extern EGLBoolean
@@ -43,15 +57,15 @@ _eglQueryDisplayMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint attribute, EGLint *
 
 extern EGLBoolean
 _eglQueryScreenSurfaceMESA(_EGLDriver *drv, EGLDisplay dpy,
-                           EGLint screen_number, EGLSurface *surface);
+                           EGLScreenMESA screen, EGLSurface *surface);
 
 
 extern EGLBoolean
-_eglQueryScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number, EGLModeMESA *mode);
+_eglQueryScreenModeMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLModeMESA *mode);
 
 
 extern EGLBoolean
-_eglQueryScreenMESA(_EGLDriver *drv, EGLDisplay dpy, EGLint screen_number, EGLint attribute, EGLint *value);
+_eglQueryScreenMESA(_EGLDriver *drv, EGLDisplay dpy, EGLScreenMESA screen, EGLint attribute, EGLint *value);
 
 
 extern void