screen: added error handling to prevent this module from failing silently

modules/access/screen/mac.c

@@ -87,27 +87,42 @@ int screen_InitCapture( demux_t *p_demux )
     CGLPixelFormatObj pix;
     GLint npix;
     GLint viewport[4];
-    
+    GLuint displayMask;
+    CGLError returnedError;
+
     p_sys->p_data = p_data =
         ( screen_data_t * )malloc( sizeof( screen_data_t ) );
-    
+
     attribs[0] = kCGLPFAFullScreen;
     attribs[1] = kCGLPFADisplayMask;
     attribs[2] = CGDisplayIDToOpenGLDisplayMask( CGMainDisplayID() );
     attribs[3] = 0;
-    
-    CGLChoosePixelFormat( attribs, &pix, &npix );
-    CGLCreateContext( pix, NULL, &( p_data->screen ) );
-    CGLDestroyPixelFormat( pix );
 
-    CGLSetCurrentContext( p_data->screen );
-    CGLSetFullScreen( p_data->screen );
-    
+    returnedError = CGLChoosePixelFormat( attribs, &pix, &npix );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLCreateContext( pix, NULL, &( p_data->screen ) );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLDestroyPixelFormat( pix );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLSetCurrentContext( p_data->screen );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLSetFullScreen( p_data->screen );
+    if (returnedError)
+        goto errorHandling;
+
     glGetIntegerv( GL_VIEWPORT, viewport );
-    
+
     p_data->screen_width = viewport[2];
     p_data->screen_height = viewport[3];
-    
+
     p_data->left = p_sys->i_left;
     p_data->top = p_sys->i_top;
     p_data->src_width = var_CreateGetInteger( p_demux, "screen-width" );
@@ -118,36 +133,49 @@ int screen_InitCapture( demux_t *p_demux )
     }
     p_data->dest_width = p_data->src_width;
     p_data->dest_height = p_data->src_height;
-    
+
     attribs [0] = kCGLPFAOffScreen;
     attribs [1] = kCGLPFAColorSize;
     attribs [2] = 32;
     attribs [3] = 0;
-    
-    CGLChoosePixelFormat( attribs, &pix, &npix );
-    CGLCreateContext( pix, NULL, &( p_data->scaled ) );
-    CGLDestroyPixelFormat( pix );
 
-    CGLSetCurrentContext( p_data->scaled );
+    returnedError = CGLChoosePixelFormat( attribs, &pix, &npix );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLCreateContext( pix, NULL, &( p_data->scaled ) );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLDestroyPixelFormat( pix );
+    if (returnedError)
+        goto errorHandling;
+
+    returnedError = CGLSetCurrentContext( p_data->scaled );
+    if (returnedError)
+        goto errorHandling;
+
     p_data->scaled_image = ( char * )malloc( p_data->dest_width
                                           * p_data->dest_height * 4 );
-    CGLSetOffScreen( p_data->scaled, p_data->dest_width, p_data->dest_height,
-                     p_data->dest_width * 4, p_data->scaled_image );
-    
+#warning FIXME: CGLSetOffScreen is no longer supported in the future!
+    returnedError = CGLSetOffScreen( p_data->scaled, p_data->dest_width, p_data->dest_height, p_data->dest_width * 4, p_data->scaled_image );
+    if (returnedError)
+        goto errorHandling;
+
     es_format_Init( &p_sys->fmt, VIDEO_ES, VLC_CODEC_RGB32 );
-    
+
     /* p_sys->fmt.video.i_* must set to screen size, not subscreen size */
     p_sys->fmt.video.i_width = p_data->screen_width;
     p_sys->fmt.video.i_visible_width = p_data->screen_width;
     p_sys->fmt.video.i_height = p_data->screen_height;
     p_sys->fmt.video.i_bits_per_pixel = 32;
-    
+
     glGenTextures( 1, &( p_data->texture ) );
     glBindTexture( GL_TEXTURE_2D, p_data->texture );
-    
+
     p_data->texture_image
       = ( char * )malloc( p_data->src_width * p_data->src_height * 4 );
-    
+
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
@@ -155,27 +183,31 @@ int screen_InitCapture( demux_t *p_demux )
 
     glGenTextures( 1, &( p_data->cursor_texture ) );
     glBindTexture( GL_TEXTURE_2D, p_data->cursor_texture );
-    
+
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );
-    
+
     CGSNewConnection( NULL, &( p_data->connection ) );
-    
+
     return VLC_SUCCESS;
+
+    errorHandling:
+    msg_Err( p_demux, "Core OpenGL failure: %s", CGLErrorString( returnedError ) );
+    return VLC_EGENERIC;
 }
 
 int screen_CloseCapture( demux_t *p_demux )
 {
     screen_data_t *p_data = ( screen_data_t * )p_demux->p_sys->p_data;
-    
+
     CGSReleaseConnection( p_data->connection );
-    
+
     CGLSetCurrentContext( NULL );
     CGLClearDrawable( p_data->screen );
     CGLDestroyContext( p_data->screen );
-    
+
     return VLC_SUCCESS;
 }
 
@@ -185,24 +217,24 @@ block_t *screen_Capture( demux_t *p_demux )
     screen_data_t *p_data = ( screen_data_t * )p_sys->p_data;
     block_t *p_block;
     int i_size;
-    
+
     i_size = p_sys->fmt.video.i_height * p_sys->fmt.video.i_width * 4; 
-    
+
     if( !( p_block = block_New( p_demux, i_size ) ) )
     {
         msg_Warn( p_demux, "cannot get block" );
         return NULL;
     }
-    
+
     CGPoint cursor_pos;
     CGError cursor_result;
-    
+
     cursor_pos.x = 0;
     cursor_pos.y = 0;
-    
+
     cursor_result
       = CGSGetCurrentCursorLocation( p_data->connection, &cursor_pos );
-    
+
     if( p_sys->b_follow_mouse
         && cursor_result == kCGErrorSuccess )
     {
@@ -210,7 +242,7 @@ block_t *screen_Capture( demux_t *p_demux )
         p_data->left = p_sys->i_left;
         p_data->top = p_sys->i_top;
     }
-    
+
     CGLSetCurrentContext( p_data->screen );
     glReadPixels( p_data->left,
                   p_data->screen_height - p_data->top - p_data->src_height,
@@ -218,14 +250,14 @@ block_t *screen_Capture( demux_t *p_demux )
                   p_data->src_height,
                   GL_RGBA, GL_UNSIGNED_BYTE,
                   p_data->texture_image );
-    
+
     CGLSetCurrentContext( p_data->scaled );
     glEnable( GL_TEXTURE_2D );
     glBindTexture( GL_TEXTURE_2D, p_data->texture );
     glTexImage2D( GL_TEXTURE_2D, 0,
                   GL_RGBA8, p_data->src_width, p_data->src_height, 0,
                   GL_RGBA, GL_UNSIGNED_BYTE, p_data->texture_image );
-    
+
     glClearColor( 0.0f, 0.0f, 0.0f, 1.0f );
     glClear( GL_COLOR_BUFFER_BIT );
     glColor3f( 1.0f, 1.0f, 1.0f );
@@ -238,13 +270,13 @@ block_t *screen_Capture( demux_t *p_demux )
     glTexCoord2f( 0.0, 0.0 ); glVertex2f( -1.0, 1.0 );
     glEnd();
     glDisable( GL_TEXTURE_2D );
-    
+
     int size;
     int tmp1, tmp2, tmp3, tmp4;
     unsigned char *cursor_image;
     CGRect cursor_rect;
     CGPoint cursor_hot;
-    
+
     if( cursor_result == kCGErrorSuccess
         && CGSGetGlobalCursorDataSize( p_data->connection, &size )
         == kCGErrorSuccess )
@@ -265,10 +297,10 @@ block_t *screen_Capture( demux_t *p_demux )
                           ( int )( cursor_rect.size.height ), 0,
                           GL_RGBA, GL_UNSIGNED_BYTE,
                           ( char * )cursor_image );
-            
+
             cursor_rect.origin.x = cursor_pos.x - p_data->left - cursor_hot.x;
             cursor_rect.origin.y = cursor_pos.y - p_data->top - cursor_hot.y;
-            
+
             cursor_rect.origin.x
               = 2.0 * cursor_rect.origin.x / p_data->src_width - 1.0;
             cursor_rect.origin.y
@@ -277,7 +309,7 @@ block_t *screen_Capture( demux_t *p_demux )
               = 2.0 * cursor_rect.size.width / p_data->src_width;
             cursor_rect.size.height
               = 2.0 * cursor_rect.size.height / p_data->src_height;
-            
+
             glColor3f( 1.0f, 1.0f, 1.0f );
             glEnable( GL_TEXTURE_2D );
             glEnable( GL_BLEND );
@@ -302,12 +334,12 @@ block_t *screen_Capture( demux_t *p_demux )
         }
         free( cursor_image );
     }
-    
+
     glReadPixels( 0, 0, 
                   p_data->dest_width,
                   p_data->dest_height,
                   GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
                   p_block->p_buffer );
-    
+
     return p_block;
 }