Implement tension and fill parameters.

src/modules/qt/filter_audiospectrum.cpp

@@ -176,6 +176,7 @@ static void draw_spectrum( mlt_filter filter, mlt_frame frame, QImage* qimg )
 	mlt_position position = mlt_filter_get_position( filter, frame );
 	mlt_position length = mlt_filter_get_length2( filter, frame );
 	int fill = mlt_properties_get_int( filter_properties, "fill" );
+	double tension = mlt_properties_get_double( filter_properties, "tension" );
 	mlt_rect rect = mlt_properties_anim_get_rect( filter_properties, "rect", position, length );
 	if ( strchr( mlt_properties_get( filter_properties, "rect" ), '%' ) ) {
 		rect.x *= qimg->width();
@@ -197,7 +198,7 @@ static void draw_spectrum( mlt_filter filter, mlt_frame frame, QImage* qimg )
 	}
 	float* spectrum = (float*)mlt_pool_alloc( bands * sizeof(float) );
 	convert_fft_to_spectrum( filter, frame, bands, spectrum );
-	paint_line_graph( p, r, bands, spectrum, fill );
+	paint_line_graph( p, r, bands, spectrum, tension, fill );
 	mlt_pool_release( spectrum );
 
 	p.end();
@@ -300,6 +301,7 @@ mlt_filter filter_audiospectrum_init( mlt_profile profile, mlt_service_type type
 		mlt_properties_set( properties, "rect", "0% 0% 100% 100%" );
 		mlt_properties_set( properties, "thickness", "0" );
 		mlt_properties_set( properties, "fill", "0" );
+		mlt_properties_set( properties, "tension", "0.4" );
 		mlt_properties_set( properties, "angle", "0" );
 		mlt_properties_set( properties, "gorient", "v" );
 		mlt_properties_set_int( properties, "bands", 31 );

src/modules/qt/filter_audiospectrum.yml

@@ -101,6 +101,18 @@ parameters:
     mutable: yes
     widget: checkbox
 
+  - identifier: tension
+    title: Line Tension
+    description: >
+      Affects the amount of curve in the line interpolating between points.
+      0.0 = a straight line between points.
+      1.0 = very curved lines between points.
+      values < 0 and > 1 will cause loops in the lines.
+    type: float
+    default: 0.4
+    readonly: no
+    mutable: yes
+
   - identifier: gorient
     title: Gradient Orientation
     description: Direction of the color gradient.

src/modules/qt/graph.cpp

@@ -96,11 +96,10 @@ void setup_graph_pen( QPainter& p, QRectF& r, mlt_properties filter_properties )
 	p.setPen(pen);
 }
 
-void paint_line_graph( QPainter& p, QRectF& rect, int points, float* values, int fill )
+void paint_line_graph( QPainter& p, QRectF& rect, int points, float* values, double tension, int fill )
 {
 	double width = rect.width();
 	double height = rect.height();
-	double t = 0.3;
 	double pixelsPerPoint = width / (double)(points - 1);
 
 	// Calculate cubic control points
@@ -121,8 +120,8 @@ void paint_line_graph( QPainter& p, QRectF& rect, int points, float* values, int
 		double y2 = rect.y() + height - values[i + 2] * height;
 		double d01 = sqrt( pow( x1 - x0, 2 ) + pow( y1 - y0, 2) );
 		double d12 = sqrt( pow( x2 - x1, 2 ) + pow( y2 - y1, 2) );
-		double fa = t * d01 / ( d01 + d12 );
-		double fb = t * d12 / ( d01 + d12 );
+		double fa = tension * d01 / ( d01 + d12 );
+		double fb = tension * d12 / ( d01 + d12 );
 		double p1x = x1 - fa * ( x2 - x0 );
 		double p1y = y1 - fa * ( y2 - y0 );
 		double p2x = x1 + fb * ( x2 - x0 );
@@ -149,5 +148,12 @@ void paint_line_graph( QPainter& p, QRectF& rect, int points, float* values, int
 		curvePath.cubicTo( c1, c2, end );
 	}
 
-	p.drawPath( curvePath );
+	if( fill ) {
+		curvePath.lineTo( rect.x() + width, rect.y() + height );
+		curvePath.lineTo( rect.x(), rect.y() + height );
+		curvePath.closeSubpath();
+		p.fillPath( curvePath, p.pen().brush() );
+	} else {
+		p.drawPath( curvePath );
+	}
 }

src/modules/qt/graph.h

@@ -26,7 +26,7 @@
 
 void setup_graph_painter( QPainter& p, QRectF& rect, mlt_properties filter_properties );
 void setup_graph_pen( QPainter& p, QRectF& rect, mlt_properties filter_properties );
-void paint_line_graph( QPainter& p, QRectF& rect, int points, float* values, int fill );
+void paint_line_graph( QPainter& p, QRectF& rect, int points, float* values, double tension, int fill );
 
 
 #endif // GRAPH_H