normal-mapper.jxs

<jittershader name="normalmapper">
    <param name="tex0" type="int" default="0" />
    <param name="size" type="vec2" default="1.0 0.0" />
    <language name="glsl" version="1.50">
        <bind param="scale" program="fp" />
        <bind param="tex0" program="fp" />
        <bind param="size" program="fp" />
        <program name="vp" type="vertex" source="sh.passthrudim.vp.glsl" />
        <program name="fp" type="fragment" >
<![CDATA[
uniform sampler2D tex0;
uniform vec2 size;

varying vec2 texcoord0;

const ivec3 off = ivec3(-1,0,1);

void main(void)
{
    vec4 wave = texture2D(tex0,texcoord0);

    float s11 = wave.x;
    float s01 = textureOffset(tex0, texcoord0, off.xy).x;
    float s21 = textureOffset(tex0, texcoord0, off.zy).x;
    float s10 = textureOffset(tex0, texcoord0, off.yx).x;
    float s12 = textureOffset(tex0, texcoord0, off.yz).x;
    vec3  va  = normalize(vec3(size.xy,s21-s01));
    vec3  vb  = normalize(vec3(size.yx,s12-s10));
    vec4 bump = vec4(cross(va,vb), s11);

    gl_FragColor = bump;
}

]]>
        </program>
    </language>
</jittershader>