Make rpi video cross-compiler friendly.

* Stops using fixed path to find GLES/EGL libs.
* Tries pkg-config to locate bcm_host.

Signed-off-by: Guillermo A. Amaral <g@maral.me>

cmake/sdlchecks.cmake

@@ -1127,15 +1127,18 @@ endmacro()
 # - n/a
 macro(CheckRPI)
   if(VIDEO_RPI)
+    pkg_check_modules(VIDEO_RPI bcm_host brcmegl)
+    if (NOT VIDEO_RPI_FOUND)
       set(VIDEO_RPI_INCLUDE_DIRS "/opt/vc/include" "/opt/vc/include/interface/vcos/pthreads" "/opt/vc/include/interface/vmcs_host/linux/" )
       set(VIDEO_RPI_LIBRARY_DIRS "/opt/vc/lib" )
-    set(VIDEO_RPI_LIBS bcm_host )
+      set(VIDEO_RPI_LIBRARIES bcm_host )
+    endif()
     listtostr(VIDEO_RPI_INCLUDE_DIRS VIDEO_RPI_INCLUDE_FLAGS "-I")
     listtostr(VIDEO_RPI_LIBRARY_DIRS VIDEO_RPI_LIBRARY_FLAGS "-L")
 
     set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
     set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${VIDEO_RPI_INCLUDE_FLAGS} ${VIDEO_RPI_LIBRARY_FLAGS}")
-    set(CMAKE_REQUIRED_LIBRARIES "${VIDEO_RPI_LIBS}")
+    set(CMAKE_REQUIRED_LIBRARIES "${VIDEO_RPI_LIBRARIES}")
     check_c_source_compiles("
         #include <bcm_host.h>
         int main(int argc, char **argv) {}" HAVE_VIDEO_RPI)
@@ -1147,7 +1150,7 @@ macro(CheckRPI)
       set(SDL_VIDEO_DRIVER_RPI 1)
       file(GLOB VIDEO_RPI_SOURCES ${SDL2_SOURCE_DIR}/src/video/raspberry/*.c)
       set(SOURCE_FILES ${SOURCE_FILES} ${VIDEO_RPI_SOURCES})
-      list(APPEND EXTRA_LIBS ${VIDEO_RPI_LIBS})
+      list(APPEND EXTRA_LIBS ${VIDEO_RPI_LIBRARIES})
       set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${VIDEO_RPI_INCLUDE_FLAGS} ${VIDEO_RPI_LIBRARY_FLAGS}")
     endif(SDL_VIDEO AND HAVE_VIDEO_RPI)
   endif(VIDEO_RPI)

configure

@@ -19502,7 +19502,51 @@ else
 fi
 
     if test x$enable_video = xyes -a x$enable_video_rpi = xyes; then
-        if test x$ARCH = xnetbsd; then
+        # Extract the first word of "pkg-config", so it can be a program name with args.
+set dummy pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_path_PKG_CONFIG" && ac_cv_path_PKG_CONFIG="no"
+  ;;
+esac
+fi
+PKG_CONFIG=$ac_cv_path_PKG_CONFIG
+if test -n "$PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PKG_CONFIG" >&5
+$as_echo "$PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+        if test x$PKG_CONFIG != xno && $PKG_CONFIG --exists bcm_host; then
+            RPI_CFLAGS=`$PKG_CONFIG --cflags bcm_host brcmegl`
+            RPI_LDFLAGS=`$PKG_CONFIG --libs bcm_host brcmegl`
+        elif test x$ARCH = xnetbsd; then
             RPI_CFLAGS="-I/usr/pkg/include -I/usr/pkg/include/interface/vcos/pthreads -I/usr/pkg/include/interface/vmcs_host/linux"
             RPI_LDFLAGS="-Wl,-R/usr/pkg/lib -L/usr/pkg/lib -lbcm_host"
         else

configure.in

@@ -1571,7 +1571,11 @@ CheckRPI()
 AC_HELP_STRING([--enable-video-rpi], [use Raspberry Pi video driver [[default=yes]]]),
                   , enable_video_rpi=yes)
     if test x$enable_video = xyes -a x$enable_video_rpi = xyes; then
-        if test x$ARCH = xnetbsd; then
+        AC_PATH_PROG(PKG_CONFIG, pkg-config, no)
+        if test x$PKG_CONFIG != xno && $PKG_CONFIG --exists bcm_host; then
+            RPI_CFLAGS=`$PKG_CONFIG --cflags bcm_host brcmegl`
+            RPI_LDFLAGS=`$PKG_CONFIG --libs bcm_host brcmegl`
+        elif test x$ARCH = xnetbsd; then
             RPI_CFLAGS="-I/usr/pkg/include -I/usr/pkg/include/interface/vcos/pthreads -I/usr/pkg/include/interface/vmcs_host/linux"
             RPI_LDFLAGS="-Wl,-R/usr/pkg/lib -L/usr/pkg/lib -lbcm_host"
         else

src/video/SDL_egl.c

@@ -44,12 +44,13 @@
 
 #if SDL_VIDEO_DRIVER_RPI
 /* Raspbian places the OpenGL ES/EGL binaries in a non standard path */
-#define DEFAULT_EGL ( vc4 ? "libEGL.so.1" : "/opt/vc/lib/libbrcmEGL.so" )
+static const char g_rpi_opt_path[] = "/opt/vc/lib";
-#define DEFAULT_OGL_ES2 ( vc4 ? "libGLESv2.so.2" : "/opt/vc/lib/libbrcmGLESv2.so" )
+#define DEFAULT_EGL ( vc4 ? "libEGL.so.1" : "libbrcmEGL.so" )
-#define ALT_EGL "/opt/vc/lib/libEGL.so"
+#define DEFAULT_OGL_ES2 ( vc4 ? "libGLESv2.so.2" : "libbrcmGLESv2.so" )
-#define ALT_OGL_ES2 "/opt/vc/lib/libGLESv2.so"
+#define ALT_EGL "libEGL.so"
-#define DEFAULT_OGL_ES_PVR ( vc4 ? "libGLES_CM.so.1" : "/opt/vc/lib/libbrcmGLESv2.so" )
+#define ALT_OGL_ES2 "libGLESv2.so"
-#define DEFAULT_OGL_ES ( vc4 ? "libGLESv1_CM.so.1" : "/opt/vc/lib/libbrcmGLESv2.so" )
+#define DEFAULT_OGL_ES_PVR ( vc4 ? "libGLES_CM.so.1" : "libbrcmGLESv2.so" )
+#define DEFAULT_OGL_ES ( vc4 ? "libGLESv1_CM.so.1" : "libbrcmGLESv2.so" )
 
 #elif SDL_VIDEO_DRIVER_ANDROID || SDL_VIDEO_DRIVER_VIVANTE
 /* Android */
@@ -265,6 +266,20 @@ SDL_EGL_LoadLibrary(_THIS, const char *egl_path, NativeDisplayType native_displa
 #endif
 #if SDL_VIDEO_DRIVER_RPI
     SDL_bool vc4 = (0 == access("/sys/module/vc4/", F_OK));
+
+    path = SDL_getenv("LD_LIBRARY_PATH");
+    if (path) {
+        const int path_size = SDL_strlen(path) + 1 + sizeof(g_rpi_opt_path);
+        char *new_path = SDL_calloc(1, path_size);
+        strcat(new_path, path);
+        strcat(new_path, ":");
+        strcat(new_path, g_rpi_opt_path);
+        SDL_setenv("LD_LIBRARY_PATH", new_path, 1);
+        SDL_free(new_path);
+    } else {
+        SDL_setenv("LD_LIBRARY_PATH", g_rpi_opt_path, 1);
+    }
+    path = NULL;
 #endif
 
     if (_this->egl_data) {