scenejs-simple-shader-backend.js

// Installation of a backend for the 'simple-shader' SceneJS shader node

SceneJs.Backend.installNodeBackend(SceneJs.shaderBackend({

    nodeType: 'simple-shader',

    vertexShaders: [
        'attribute vec3 Vertex; ' +
        'attribute vec3 Normal; ' +

        'uniform mat4 PMatrix; ' +
        'uniform mat4 MVMatrix; ' +

        'uniform vec4 LightPos; ' +
        'varying vec4 FragColor; ' +

        'uniform vec3 MaterialDiffuse;' +
        'uniform vec3 MaterialSpecular;' +
        'uniform vec3 MaterialAmbient;' +

        'void main(void) { ' +
        '   vec4 v = vec4(Vertex, 1.0); ' +
        '   vec4 vmv = MVMatrix * v; ' +
        '   gl_Position = PMatrix * vmv; ' +

        '   vec3 lightDir = vec3(normalize(vmv - LightPos)); ' +

        '   float NdotL = max(dot(lightDir, Normal), 0.0); ' +

        '   vec3 diffuse = MaterialDiffuse + MaterialSpecular; ' +

        '   FragColor = vec4(NdotL * diffuse + MaterialAmbient, 1.0); ' +
        '}'
    ],

    fragmentShaders: [
        'varying float intensity; ' +
        'varying vec4 FragColor; ' +
        'void main(void) { ' +
        '      gl_FragColor = FragColor; ' +
        '}'
    ],

    /** Setter functions to inject data into the scripts via the GL context. 
     * Note that in some cases these also convert the incoming data objects 
     * to the target variable types.
     *
     */
    setters : {

        scene_ModelViewMatrix: function(gl, findVar, mat) {
            if (mat) {
                gl.uniformMatrix4fv(findVar(gl, 'MVMatrix'), mat.flatten());
            }
        },

        scene_ProjectionMatrix: function(gl, findVar, mat) {
            if (mat) {
                gl.uniformMatrix4fv(findVar(gl, 'PMatrix'), mat.flatten());
            }
        },

        scene_Normal: function(gl, findVar, normals) {
            if (normals) {
                var loc = findVar(gl, 'Normal');
                gl.vertexAttribPointer(loc, 3, gl.FLOAT, false, 0, normals);
                gl.enableVertexAttribArray(loc);
            }
        },

        scene_Vertex: function(gl, findVar, vertices) {
            if (vertices) {
                var loc = findVar(gl, 'Vertex') ;
                gl.vertexAttribPointer(loc, 3, gl.FLOAT, false, 0, vertices);
                gl.enableVertexAttribArray(loc);
            }
        },

        scene_Material: function(gl, findVar, m) {
            if (m) {
                gl.uniform4fv(findVar(gl, 'MaterialAmbient'), 
                       $V([m.ambient.r, m.ambient.g, m.ambient.b, m.ambient.a]).flatten());
                gl.uniform4fv(findVar(gl, 'MaterialDiffuse'), 
                       $V([m.diffuse.r, m.diffuse.g, m.diffuse.b, m.diffuse.a]).flatten());
                gl.uniform4fv(findVar(gl, 'MaterialSpecular'), 
                       $V([m.specular.r, m.specular.g, m.specular.b, m.specular.a]).flatten());
            }
        },

        scene_Lights: function(gl, findVar, lights) {
            if (lights && lights.length > 0) {
                var l = lights[0];
                gl.uniform4fv(findVar(gl, 'LightPos'), 
                       $V([l.pos.x, l.pos.y, l.pos.z, 1.0]).flatten());
            }
        }
    }
}));