Function drawAudioBuffer

samples/_audio/common/AudioDrawUtils.cpp:37–67

using namespace ci;

void drawAudioBuffer( const audio::Buffer &buffer, const Rectf &bounds, bool drawFrame, const ci::ColorA &color )
{
	gl::ScopedGlslProg glslScope( getStockShader( gl::ShaderDef().color() ) );

	gl::color( color );

	const float waveHeight = bounds.getHeight() / (float)buffer.getNumChannels();
	const float xScale = bounds.getWidth() / (float)buffer.getNumFrames();

	float yOffset = bounds.y1;
	for( size_t ch = 0; ch < buffer.getNumChannels(); ch++ ) {
		PolyLine2f waveform;
		const float *channel = buffer.getChannel( ch );
		float x = bounds.x1;
		for( size_t i = 0; i < buffer.getNumFrames(); i++ ) {
			x += xScale;
			float y = ( 1 - ( channel[i] * 0.5f + 0.5f ) ) * waveHeight + yOffset;
			waveform.push_back( vec2( x, y ) );
		}

		if( ! waveform.getPoints().empty() )
			gl::draw( waveform );

		yOffset += waveHeight;
	}

	if( drawFrame ) {
		gl::color( color.r, color.g, color.b, color.a * 0.6f );
		gl::drawStrokedRect( bounds );
	}
}

// ----------------------------------------------------------------------------------------------------
// MARK: - WaveformPlot