standalone/002_simple_path.cpp

Shows simple usage of the NV_path_rendering extensionCopyright 2008-2014 Matus Chochlik. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#include "glut_glew_example.hpp"

#include <oglplus/all.hpp>
#include <oglplus/ext/ARB_compatibility.hpp>
#include <oglplus/ext/NV_path_rendering.hpp>

class PathExample
 : public oglplus::StandaloneExample
{
private:
    oglplus::Context gl;
    oglplus::ARB_compatibility glc;
    oglplus::NV_path_rendering pr;

    oglplus::PathNV path;
public:
    PathExample(int, const char**)
    {
        using namespace oglplus;

        path.Spec(PathNVSpec<GLfloat>(6, 10)
            .MoveTo( 0.00f, 0.85f)
            .LineTo( 0.65f,-0.80f)
            .LineTo(-0.85f, 0.30f)
            .LineTo( 0.85f, 0.30f)
            .LineTo(-0.65f,-0.80f)
            .Close()
        );

        path.StrokeWidth(0.01);
        path.JoinStyle(PathNVJoinStyle::Round);

        path.Dashes(0.05f, 0.02f);

        glc.MatrixMode(CompatibilityMatrixMode::Projection);
        glc.LoadIdentity();
        glc.MatrixMode(CompatibilityMatrixMode::Modelview);
        glc.LoadIdentity();

        gl.ClearColor(1.0f, 1.0f, 1.0f, 0.0f);
        gl.ClearStencil(0);
        gl.StencilMask(~0);
        gl.StencilFunc(CompareFunction::NotEqual, 0, 0x1F);
        gl.StencilOp(
            StencilOperation::Keep,
            StencilOperation::Keep,
            StencilOperation::Zero
        );

        gl.Enable(Capability::StencilTest);
    }

    void Render(void)
    {
        using namespace oglplus;

        gl.Clear().ColorBuffer().StencilBuffer();

        glc.Color(0.2, 0.2, 1.0);

        path.StencilFill(PathNVFillMode::CountUp, 0x1F);
        path.CoverFill(PathNVFillCoverMode::BoundingBox);

        glc.Color(0.1, 0.1, 0.1);

        path.StencilStroke(1, ~0);
        path.CoverStroke(PathNVStrokeCoverMode::ConvexHull);
    }

    void Reshape(void)
    {
        using namespace oglplus;

        gl.Viewport(Width(), Height());
    }
};

int main(int argc, char* argv[])
{
    return oglplus::GlutGlewMain<PathExample>(
        "Simple example of NV_path_rendering",
        argc, argv
    );
}