Problem with effect

/////////////////////////////////////////////////////////
// NewPlugin

//The current foreground texture co-ordinate
varying mediump vec2 vTex;
//The foreground texture sampler, to be sampled at vTex
uniform lowp sampler2D samplerFront;
//The current foreground rectangle being rendered
uniform mediump vec2 srcStart;
uniform mediump vec2 srcEnd;
//The current foreground source rectangle being rendered
uniform mediump vec2 srcOriginStart;
uniform mediump vec2 srcOriginEnd;
//The current foreground source rectangle being rendered, in layout 
uniform mediump vec2 layoutStart;
uniform mediump vec2 layoutEnd;
//The background texture sampler used for background - blending effects
uniform lowp sampler2D samplerBack;
//The current background rectangle being rendered to, in texture co-ordinates, for background-blending effects
uniform mediump vec2 destStart;
uniform mediump vec2 destEnd;
//The time in seconds since the runtime started. This can be used for animated effects
uniform mediump float seconds;
//The size of a texel in the foreground texture in texture co-ordinates
uniform mediump vec2 pixelSize;
//The current layer scale as a factor (i.e. 1 is unscaled)
uniform mediump float layerScale;
//The current layer angle in radians.
uniform mediump float layerAngle;

precision mediump float;

float pixelWidth;
float pixelHeight;
vec2 iResolution = vec2( 1.0/pixelWidth, 1.0/pixelHeight);

vec3 light = vec3(-1.0, -1.0, 1.5);
vec3 light_color = vec3(1.0, 1.0, 1.0);
vec3 sphere = vec3(0.0, 0.0, 3.0);
float sphere_size = 1.3;
vec3 sphere_color = vec3(1.0, 1.0, 1.0);

float raySphere(vec3 rpos, vec3 rdir, vec3 sp, float radius, inout vec3 point, inout vec3 normal) 
{
	radius = radius * radius;
	float dt = dot(rdir, sp - rpos);
	if (dt < 0.0) 
	{
	 return -1.0;
	}
	vec3 tmp = rpos - sp;
	tmp.x = dot(tmp, tmp);
	tmp.x = tmp.x - dt*dt;
	if (tmp.x >= radius) 
	{
		return -1.0;
	}
	dt = dt - sqrt(radius - tmp.x);
	point = rpos + rdir * dt;
	normal = normalize(point - sp);
	return dt;
}
 
void main(void)
{
	light.xy = vec2(700.0, 500.0) / iResolution.xy * 2.0 - 1.0;
	light.y = -light.y;
	vec3 point; 
	vec3 normal;
	vec2 uv = vTex * 2.0 - 1.0;
	//uv.x *= iResolution.x / iResolution.y;
	uv.y = -uv.y;
	vec3 ray = vec3(uv.x, uv.y, 1.0);
	ray = normalize(ray);
	vec4 fragColor = vec4(0.0);
	float dist = raySphere(vec3(0.0), ray, sphere, sphere_size, point, normal); 
	if (dist > 0.0) 
	{
		 vec3 tmp = normalize(light - sphere);
		 float u = atan(normal.z, normal.x) / 3.1415*2.0 + seconds / 5.0;
		 float v = asin(normal.y) / 3.1415*2.0 + 0.5;
		 normal = normalize(normal * texture2D(samplerFront, vec2(u, v)).xyz);
		 u = atan(normal.z, normal.x) / 3.1415*2.0 + seconds / 5.0;
		 v = asin(normal.y) / 3.1415*2.0 + 0.5;
 float gg = clamp(dot(reflect(tmp, normal), ray), 0.0, 1.0);
 gg = pow(gg, 1600.0)*5.0;
		 fragColor.xyz = vec3(dot(tmp, normal)) * light_color * sphere_color * texture2D(samplerFront, vec2(u, v)).xyz + gg;
	 lowp float a = texture2D(samplerFront, vTex).a;
	 gl_FragColor = vec4(fragColor.xyz, a);
	} 
	
}