MyCairoControl.h

#ifndef __MY_CAIRO_CONTROL_H__
#define __MY_CAIRO_CONTROL_H__

// In case you forget it
#ifndef CAIRO_WIN32_STATIC_BUILD
#define CAIRO_WIN32_STATIC_BUILD
#endif

#include <cairo\cairo.h>

#include "IControl.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

class MyCairoControl : public IControl {
protected:
	cairo_surface_t *surface;
	cairo_t *cr;

public:
	MyCairoControl(IPlugBase *pPlug, IRECT pR, int paramIdx) : IControl(pPlug, pR, paramIdx) {
		surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, this->mRECT.W(), this->mRECT.H());
		cr = cairo_create(surface);
	};
	~MyCairoControl() {
		cairo_destroy(cr);
		cairo_surface_destroy(surface);
	};

	bool IsDirty() { return true; };

	bool Draw(IGraphics* pGraphics) {
		// We clear the surface
		cairo_save(cr);
		cairo_set_source_rgba(cr, 0, 0, 0, 0);
		cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
		cairo_paint(cr);
		cairo_restore(cr);


		// This parameter (unused for now) will be used soon for the button
		double position = (this->GetParam()->GetMax() - this->GetParam()->Value()) * this->mRECT.H() / 100.;

		// We define the main color to use, a transparent red color
		cairo_set_source_rgba(cr, 0.8, 0., 0., 0.75);

		// We draw two bezier lines with one point at top
		cairo_set_line_width(cr, 4.);

		// First bezier, 0 to middle of graphic
		// NOTE that 0:0 coordinate is the top/left corner
		// And cairo is position to 0 not where the IControl is placed
		// So the bottom/left is at 0 - height position
		double width = (double)this->mRECT.W();
		double height = (double)this->mRECT.H();

		// This is the 0 - half X path
		cairo_move_to(cr, 0, height);
		cairo_curve_to(cr, width / 4, height, width / 4, position, width / 2, position);

		// This is the half - full width X path
		cairo_move_to(cr, width / 2, position);
		cairo_curve_to(cr, 3 * width / 4, position, 3 * width / 4, height, width, height);

		// Render
		cairo_stroke(cr);

		// Now we draw the center points
		// We make it more red
		cairo_set_source_rgba(cr, 1, 0., 0., 0.75);
		cairo_set_line_width(cr, 1.);
		// Make the circle and fill it
		cairo_arc(cr, width / 2, position, 4., 0, 2 * M_PI);
		cairo_stroke_preserve(cr);
		cairo_fill(cr);

		
		// And we render
		cairo_surface_flush(surface);
		unsigned int *data = (unsigned int*)cairo_image_surface_get_data(surface);
		// This is the important part where you bind the cairo data to LICE
		LICE_WrapperBitmap WrapperBitmap = LICE_WrapperBitmap(data, this->mRECT.W(), this->mRECT.H(), this->mRECT.W(), false);

		// And we render
		IBitmap result(&WrapperBitmap, WrapperBitmap.getWidth(), WrapperBitmap.getHeight());
		return pGraphics->DrawBitmap(&result, &this->mRECT);
	};
};

#endif