standalone/003_dsa_texture.cpp

Shows usage of the direct state access texture wrapperCopyright 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/images/checker.hpp>
#include <oglplus/shapes/cube.hpp>
#include <oglplus/shapes/wrapper.hpp>
#include <oglplus/opt/list_init.hpp>
#include <oglplus/dsa/texture.hpp>

#include <vector>

class DSATextureExample
 : public oglplus::StandaloneExample
{
private:
    oglplus::Context gl;

    oglplus::Program prog;

    static oglplus::Program make_prog(void)
    {
        using namespace oglplus;

        Program prog;

        VertexShader vs;
        vs.Source(
            "#version 330\n"
            "uniform mat4 ProjectionMatrix, CameraMatrix, ModelMatrix;"
            "uniform vec3 LightPos;"
            "in vec4 Position;"
            "in vec3 Normal;"
            "in vec2 TexCoord;"
            "out vec3 vertNormal;"
            "out vec3 vertLight;"
            "out vec2 vertTexCoord;"
            "void main(void)"
            "{"
            "   vertNormal = mat3(ModelMatrix)*Normal;"
            "   gl_Position = ModelMatrix * Position;"
            "   vertLight = LightPos - gl_Position.xyz;"
            "   vertTexCoord = TexCoord;"
            "   gl_Position = ProjectionMatrix * CameraMatrix * gl_Position;"
            "}"
        ).Compile();

        FragmentShader fs;
        fs.Source(
            "#version 330\n"
            "uniform sampler2D Checker;"
            "in vec3 vertNormal;"
            "in vec3 vertLight;"
            "in vec2 vertTexCoord;"
            "out vec4 fragColor;"
            "void main(void)"
            "{"
            "   float d = dot(vertNormal, normalize(vertLight));"
            "   float i = 0.4 + 1.4*max(d, 0.0);"
            "   vec4 t  = texture(Checker, vertTexCoord);"
            "   fragColor = vec4(t.rrr*i, 1.0);"
            "}"
        ).Compile();

        prog.AttachShader(vs).AttachShader(fs).Link().Use();

        return prog;
    }

    oglplus::Uniform<oglplus::Mat4f>
        projection_matrix,
        camera_matrix,
        model_matrix;

    oglplus::shapes::ShapeWrapper textured_cube;

    oglplus::DSATextureEXT checker;
public:
    DSATextureExample(int /*argc*/, const char** /*argv*/)
     : gl()
     , prog(make_prog())
     , projection_matrix(prog, "ProjectionMatrix")
     , camera_matrix(prog, "CameraMatrix")
     , model_matrix(prog, "ModelMatrix")
     , textured_cube(
        oglplus::List("Position")("Normal")("TexCoord").Get(),
        oglplus::shapes::Cube(),
        prog
    )
    {
        using namespace oglplus;

        checker.target = Texture::Target::_2D;
        checker.Image2D(images::CheckerRedBlack(256, 256, 8, 8));
        checker.GenerateMipmap();
        checker.MinFilter(TextureMinFilter::LinearMipmapLinear);
        checker.MagFilter(TextureMagFilter::Linear);
        checker.Anisotropy(2.0);
        checker.WrapS(TextureWrap::Repeat);
        checker.WrapT(TextureWrap::Repeat);
        checker.Bind();
        (prog/"Checker") = 0;
        (prog/"LightPos") = Vec3f(10.0f, 20.0f, 30.0f);

        gl.ClearColor(0.3f, 0.3f, 0.3f, 0.0f);
        gl.ClearDepth(1.0f);
        gl.Enable(Capability::DepthTest);
        gl.Enable(Capability::CullFace);
    }

    void Render(void)
    {
        using namespace oglplus;

        gl.Clear().ColorBuffer().DepthBuffer();

        camera_matrix.Set(
            CamMatrixf::Orbiting(
                Vec3f(),
                9.5 - SineWave(FrameTime() / 6.0) * 7.0,
                FullCircles(FrameTime() / 9.0),
                Degrees(SineWave(FrameTime() / 30.0) * 90)
            )
        );

        model_matrix.Set(ModelMatrixf::RotationX(FullCircles(FrameTime() * 0.1)));

        textured_cube.Draw();
    }

    void Reshape(void)
    {
        using namespace oglplus;

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

        projection_matrix.Set(
            CamMatrixf::PerspectiveX(
                Degrees(60),
                Aspect(),
                1, 50
            )
        );
    }
};

int main(int argc, char* argv[])
{
    return oglplus::GlutGlewMain<DSATextureExample>(
        "Example of EXT_direct_state_access texture usage",
        argc, argv
    );
}