From 012217f069cb28d6b877001c9ef38a8dde57f39a Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Tue, 18 Oct 2016 23:24:49 -0700
Subject: [PATCH] Fixed bug 3369 - RaspberryPI ability to specify a Dispmanx
 layer

Albert Casals

On a RaspberryPI, it might become convenient to specify the Dispmanx layer SDL uses.
Currently, it is hardcoded to be 10000 to sit above most applications.

This can be specially useful when integrating other graphical apps and frameworks like OMXplayer, QT5 etc.. in order to have more flexibility on their Z-order.
---
 include/SDL_hints.h                |  8 ++++++++
 src/video/raspberry/SDL_rpimouse.c | 12 ++++++++++--
 src/video/raspberry/SDL_rpivideo.c | 21 +++++++++++++++++++--
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/include/SDL_hints.h b/include/SDL_hints.h
index 9efb9550c4dec..dd1546431abe0 100644
--- a/include/SDL_hints.h
+++ b/include/SDL_hints.h
@@ -699,6 +699,14 @@ extern "C" {
  */
 #define SDL_HINT_WINDOWS_DISABLE_THREAD_NAMING "SDL_WINDOWS_DISABLE_THREAD_NAMING"
 
+/**
+ * \brief Tell SDL which Dispmanx layer to use on a Raspberry PI
+ *
+ * Also known as Z-order. The variable can take a negative or positive value.
+ * The default is 10000.
+ */
+#define SDL_HINT_RPI_VIDEO_LAYER           "SDL_RPI_VIDEO_LAYER"
+
 /**
  *  \brief  An enumeration of hint priorities
  */
diff --git a/src/video/raspberry/SDL_rpimouse.c b/src/video/raspberry/SDL_rpimouse.c
index 3a84254aeec2f..ae9bdfd5cbfb3 100644
--- a/src/video/raspberry/SDL_rpimouse.c
+++ b/src/video/raspberry/SDL_rpimouse.c
@@ -24,6 +24,7 @@
 
 #include "SDL_assert.h"
 #include "SDL_surface.h"
+#include "SDL_hints.h"
 
 #include "SDL_rpivideo.h"
 #include "SDL_rpimouse.h"
@@ -117,7 +118,9 @@ RPI_ShowCursor(SDL_Cursor * cursor)
     SDL_VideoDisplay *display;
     SDL_DisplayData *data;
     VC_DISPMANX_ALPHA_T alpha = {  DISPMANX_FLAGS_ALPHA_FROM_SOURCE /* flags */ , 255 /*opacity 0->255*/,  0 /* mask */ };
-    
+    uint32_t layer = SDL_RPI_MOUSELAYER;
+    const char *env;
+
     mouse = SDL_GetMouse();
     if (mouse == NULL) {
         return -1;
@@ -167,9 +170,14 @@ RPI_ShowCursor(SDL_Cursor * cursor)
         update = vc_dispmanx_update_start(10);
         SDL_assert(update);
 
+        env = SDL_GetHint(SDL_HINT_RPI_VIDEO_LAYER);
+        if (env) {
+            layer = SDL_atoi(env) + 1;
+        }
+
         curdata->element = vc_dispmanx_element_add(update,
                                                     data->dispman_display,
-                                                    SDL_RPI_MOUSELAYER, // layer
+                                                    layer,
                                                     &dst_rect,
                                                     curdata->resource,
                                                     &src_rect,
diff --git a/src/video/raspberry/SDL_rpivideo.c b/src/video/raspberry/SDL_rpivideo.c
index 40a398a03ffb1..67dc77b1c5e2a 100644
--- a/src/video/raspberry/SDL_rpivideo.c
+++ b/src/video/raspberry/SDL_rpivideo.c
@@ -38,6 +38,7 @@
 #include "SDL_events.h"
 #include "../../events/SDL_mouse_c.h"
 #include "../../events/SDL_keyboard_c.h"
+#include "SDL_hints.h"
 
 #ifdef SDL_INPUT_LINUXEV
 #include "../../core/linux/SDL_evdev.h"
@@ -221,6 +222,8 @@ RPI_CreateWindow(_THIS, SDL_Window * window)
     VC_RECT_T src_rect;
     VC_DISPMANX_ALPHA_T         dispman_alpha;
     DISPMANX_UPDATE_HANDLE_T dispman_update;
+    uint32_t layer = SDL_RPI_VIDEOLAYER;
+    const char *env;
 
     /* Disable alpha, otherwise the app looks composed with whatever dispman is showing (X11, console,etc) */
     dispman_alpha.flags = DISPMANX_FLAGS_ALPHA_FIXED_ALL_PIXELS; 
@@ -253,11 +256,25 @@ RPI_CreateWindow(_THIS, SDL_Window * window)
     src_rect.width = window->w << 16;
     src_rect.height = window->h << 16;
 
+    env = SDL_GetHint(SDL_HINT_RPI_VIDEO_LAYER);
+    if (env) {
+        layer = SDL_atoi(env);
+    }
+
     dispman_update = vc_dispmanx_update_start( 0 );
-    wdata->dispman_window.element = vc_dispmanx_element_add ( dispman_update, displaydata->dispman_display, SDL_RPI_VIDEOLAYER /* layer */, &dst_rect, 0/*src*/, &src_rect, DISPMANX_PROTECTION_NONE, &dispman_alpha /*alpha*/, 0/*clamp*/, 0/*transform*/);
+    wdata->dispman_window.element = vc_dispmanx_element_add (dispman_update,
+                                                             displaydata->dispman_display,
+                                                             layer /* layer */,
+                                                             &dst_rect,
+                                                             0 /*src*/,
+                                                             &src_rect,
+                                                             DISPMANX_PROTECTION_NONE,
+                                                             &dispman_alpha /*alpha*/,
+                                                             0 /*clamp*/,
+                                                             0 /*transform*/);
     wdata->dispman_window.width = window->w;
     wdata->dispman_window.height = window->h;
-    vc_dispmanx_update_submit_sync( dispman_update );
+    vc_dispmanx_update_submit_sync(dispman_update);
     
     if (!_this->egl_data) {
         if (SDL_GL_LoadLibrary(NULL) < 0) {