panda3d/samples/distortion/distortion.sha

//Cg
//
// time
//
//   You need to pass the frame time here.
//
// desat.x
//
//   Desaturation level.  If zero, the bloom's color is equal to
//   the color of the input pixel.  If one, the bloom's color is
//   white.
//
// trigger.x
//
//   Must be equal to mintrigger.
//
//   mintrigger is the minimum brightness to trigger a bloom,
//   and maxtrigger is the brightness at which the bloom
//   reaches maximum intensity.
//
// trigger.y
//
//   Must be equal to (1.0/(maxtrigger-mintrigger)) where
//   
//   mintrigger is the minimum brightness to trigger a bloom,
//   and maxtrigger is the brightness at which the bloom
//   reaches maximum intensity.
//

void vshader(float4 vtx_position : POSITION,
             uniform float4x4 mat_modelproj,
             uniform float4x4 trans_model_to_clip,
             out float4 l_position : POSITION,
             out float4 l_texcoord0 : TEXCOORD0)
{
    l_position = mul(mat_modelproj, vtx_position);
    l_texcoord0 = mul(trans_model_to_clip, vtx_position);
    l_texcoord0.z = l_texcoord0.w;
}

void fshader(float4 l_texcoord0 : TEXCOORD0,
       	     uniform sampler2D k_screen : TEXUNIT1,
             uniform sampler2D k_waves : TEXUNIT0,
             uniform float4 texpad_screen,
             in uniform float sys_time,
             out float4 o_color : COLOR)
{
    float3 screen = l_texcoord0.xyz / l_texcoord0.w;
    float2 texcoords = float2(screen.xy) * texpad_screen.xy + texpad_screen.xy;
    float4 disturbance = tex2D(k_waves, texcoords);
    //o_color = tex2D(k_screen, texcoords + disturbance.xy * 0.05 * disturbance.z * sys_time.x * 1);
    o_color = tex2D(k_screen, texcoords + disturbance.xy * 0.05 * disturbance.z * sin(sys_time.x) * 1);
}