Develop Reference

How to remove horizontal stripe artifact from GLSL shader?

I'm working on custom photo with depth effect view.I am passing touch coordinates to GLSurfaceView renderer to "change perspective".But there are horizontal stripes between texture and it's mirrow when doing this.
My fragment shader code:
#ifdef GL_ES
precision highp float;
#endif
varying vec2 texcoordVarying;
uniform sampler2D texture;
uniform sampler2D depth;
uniform float time;
uniform vec2 touch;
uniform vec2 limit;
uniform vec4 resolution;
vec2 mirrored(vec2 v) {
vec2 m = mod(v,2.);
return mix(m,2.0 - m, step(1.0 ,m));
}
void main(void) {
vec2 uv = 1.0 * gl_FragCoord.xy / resolution.xy ;
vec2 vUv = (uv - vec2(0.5))*resolution.zw + vec2(0.5);
vUv.y = 1. - vUv.y;
vec4 tex1 = texture2D(depth,mirrored(vUv));
vec2 fake3d = vec2(vUv.x + (tex1.r - 0.5)* touch.x/limit.x, vUv.y + (tex1.r - 0.5)* touch.y/limit.y );
gl_FragColor = texture2D(texture,mirrored(fake3d));
}
I am passing coordinates like this:
queueEvent {
renderer.touchTargetX = event.rawX / renderer.width
renderer.touchTargetY = event.rawY / renderer.height
}
requestRender()

If your wrap mode is GL_REPEAT, try using GL_CLAMP_TO_EDGE.

Game runs fine on newer devices but not on older

My games runs fine on newer devices (eg..droid turbo, galaxy note 3) but on my motorola xoom there are problems, such as :
1) My shaderProgram causes the stage that is drawn inside of it to not be rendered
2) Touch inputs don't work every time using InputProcessor (only senses 90% of the time)
These are the problems I currently notice. Could this be because it is an older OS version (4.1.2)? Not that old. Are known bugs with libgdx's ShaderProgram? Even then, the touch input not sensing every click is very strange. Thanks for your time and help! My rendering code for the shaderProgram is all correct, so no need to show that. And for touchInput, I am just using touchDown method from InputProcessor.
EDIT :
Error produced by shaderProgram
"(22) : error C1101: ambiguous overloaded function reference "smoothstep(mediump float, float, lowp float)"
Vertex Shader
#version 100
attribute vec4 a_position;
attribute vec4 a_color;
attribute vec2 a_texCoord0;
uniform mat4 u_worldView;
uniform vec2 u_lightPos;
uniform vec3 u_lightColor;
uniform vec4 u_spaceColor;
varying vec4 v_color;
varying vec2 v_texCoords;
varying vec2 v_lightPos;
varying vec3 v_lightColor;
varying vec2 v_position;
varying vec4 v_spaceColor;
void main() {
v_color = a_color;
v_lightColor = u_lightColor;
v_lightPos = u_lightPos;
v_position.xy = a_position.xy;
v_texCoords = a_texCoord0;
gl_Position = u_worldView * a_position;
v_spaceColor = u_spaceColor;
}
Fragment Shader
#version 100
#ifdef GL_ES
precision lowp float;
#endif
varying vec4 v_color;
varying vec2 v_texCoords;
varying vec2 v_lightPos;
varying vec3 v_lightColor;
varying vec2 v_position;
varying vec4 v_spaceColor;
uniform sampler2D u_texture;
void main() {
for(int row = 0; row < 2; row++) {
for(int col = 0; col < 2; col++) {
float dist = distance(v_position, vec2(-1 + col, 1 - row));
float delta = 0.1;
float alpha = smoothstep(100.0-delta, 100.0, dist);
if(dist > 23.0){
gl_FragColor = mix(v_spaceColor, v_color, alpha);
}
else{
gl_FragColor = v_color * texture2D(u_texture, v_texCoords);
}
}
}
}

OpenGL ES GLSL optimization

I'm developing a game which uses glsl shader to produce terrain based on the vertex "height". This works very very fast on desktop but quite slow on android tablet. This is of course natural. I'm still a noob with GLSL and OpenGL. This is the result from the shader:
lowp setting doesn't affect that much for performance. I have now tuned this and frame rate is ~20. Can someone give ideas how to improve this shader code:
Fragment shader:
#ifdef GL_ES
#define LOWP lowp
precision mediump float;
#else
#define LOWP
#endif
varying float EyeVertexZ;
//varying LOWP float Explored;
varying LOWP vec2 v_texCoords;
uniform LOWP float u_offset;
uniform sampler2D u_texture;
uniform sampler2D u_texture2;
uniform sampler2D u_texture3;
uniform vec2 resolution;
void main() {
LOWP vec4 color;
vec4 colorGrass = vec4(0.631, 0.69, 0.49 ,1.0);
float a;
float height = EyeVertexZ;
color = colorGrass;
//if height under 0.67 --> water
if(height < 0.67)
{
vec2 coords = v_texCoords.st;
coords.x -= u_offset;
LOWP vec3 nColor;
float bumpAmount = 0.2;
//bumpmapping texture
nColor = texture2D(u_texture, coords).rgb;
//water color, deep water darker
color = vec4(0.3, 0.4 + EyeVertexZ*0.33,0.6 + EyeVertexZ*0.33 ,1.0);
bool useNormals = true;
bool useShadow = true;
bool yInvert = false;
vec3 lightColor = vec3(1.0, 1.0, 1.0);
vec3 attenuation = vec3(0.5, 0.5,0.5);
vec3 ambientColor = vec3(1.0, 1.0, 1.0);
vec4 v_color = vec4(1.0, 1.0, 1.0, 1.0);
float ambientIntensity = 0.3;
vec3 light = vec3(resolution.x, 0.0, 0.5);
//some bump map programs will need the Y value flipped..
nColor.g = yInvert ? 1.0 - nColor.g : nColor.g;
//this is for debugging purposes, allowing us to lower the intensity of our bump map
LOWP vec3 nBase = vec3(0.5, 0.5, 1.0);
nColor = mix(nBase, nColor, bumpAmount);
//normals need to be converted to [-1.0, 1.0] range and normalized
LOWP vec3 normal = normalize(nColor * 2.0 - 1.0);
//here we do a simple distance calculation
LOWP vec3 deltaPos = vec3( (light.xy - gl_FragCoord.xy) / resolution.xy, light.z);
LOWP vec3 lightDir = normalize(deltaPos);
LOWP float lambert = useNormals ? clamp(dot(normal, lightDir), 0.0, 1.0) : 1.0;
//now let's get a nice little falloff
LOWP float d = sqrt(dot(deltaPos, deltaPos));
LOWP float att = useShadow ? 1.0 / ( attenuation.x + (attenuation.y*d) + (attenuation.z*d*d) ) : 1.0;
LOWP vec3 result = (ambientColor * ambientIntensity) + (lightColor.rgb * lambert) * att;
result *= color.rgb;
color = v_color * vec4(result, color.a);
}
a = height - 0.65;
a = max(a,0.0);
color = mix(color, texture2D(u_texture2, v_texCoords),a < 0.02 ? a*50.0 : 0.0);
if(height > 0.67 && height <= 0.70)
{
a = height-0.67;
color = mix( texture2D(u_texture2, v_texCoords),color, a*33.0);
}
gl_FragColor = color; //mix(color, hex, hex.a);
}
Vertex shader
#ifdef GL_ES
#define LOWP lowp
precision mediump float;
#else
#define LOWP
#endif
attribute vec4 a_position;
attribute vec2 a_texCoords;
uniform mat4 u_worldView;
varying LOWP float noise;
varying float EyeVertexZ;
varying LOWP float Explored;
varying vec2 v_texCoords;
void main() {
gl_Position = u_worldView*a_position;
EyeVertexZ = a_position.z;
v_texCoords = a_texCoords;
}

GL_BYTE normals not interpreted properly in Android shader

My shader works GREAT on iOS and Win32. The problem is Android. All devices really botch the normals if I send them as GL_BYTE. If I convert them to GL_FLOAT, everything's peachy.
glVertexAttribPointer(program->slots[Shaders::A_NORMAL_SLOT], 3, GL_FLOAT, GL_FALSE, 0, frame->normals);
glVertexAttribPointer(program->slots[Shaders::A_NORMAL_SLOT], 3, GL_BYTE, GL_TRUE, 0, frame->normals);
and YES, 'frame->normals' is of type float* in the first example, and of type char* in the second example. Like I said, this exact same code works great on iOS/Win32.
What's going on here? Is this some kind of Android bug that it won't accept byte normals?
My shader, Vertex:
uniform mat3 normal_matrix;
uniform mat4 mvp_matrix;
uniform vec3 u_lightpos;
uniform vec3 u_eyepos;
uniform vec4 u_color;
attribute vec4 a_vertex;
attribute vec3 a_normal;
attribute vec2 a_texcoord0;
attribute vec4 a_color;
varying vec2 v_texcoord0;
varying vec3 v_viewDir;
varying vec3 v_lightDir;
varying vec3 v_normal;
varying vec4 v_color;
void main( void )
{
vec4 fvObjectPosition = mvp_matrix * (a_vertex);
v_viewDir = u_eyepos;
v_lightDir = u_lightpos;
v_normal = normalize(normal_matrix * a_normal);
v_color = u_color * a_color;
v_texcoord0 = a_texcoord0.xy;
gl_Position = fvObjectPosition;
}
Fragment:
#ifdef GL_ES
precision mediump float;
#endif
uniform vec4 u_specular;
uniform vec4 u_diffuse;
uniform float u_specularpower;
uniform sampler2D t_texture0;
varying vec2 v_texcoord0;
varying vec3 v_viewDir;
varying vec3 v_lightDir;
varying vec3 v_normal;
varying vec4 v_color;
void main( void )
{
float fNDotL = dot( v_normal, v_lightDir );
vec3 fvReflection = normalize( ( ( 2.0 * v_normal ) * fNDotL ) - v_lightDir );
vec4 fvBaseColor = v_color * texture2D( t_texture0, v_texcoord0 );
vec4 fvTotalDiffuse = vec4((u_diffuse * fNDotL).xyz, 1.0) * fvBaseColor;
vec4 fvTotalSpecular = u_specular * ( pow( max( 0.0, dot( fvReflection, -v_viewDir ) ), u_specularpower ) );
gl_FragColor = vec4(( fvBaseColor + fvTotalDiffuse + fvTotalSpecular ).xyz, v_color.w);
}

OpenGLES 2.0 Phong shader strange result, makes my object transparent when texture is enabled!

I've been stuck for several days now, trying to make my shader working properly.
The problem is that when I'm not attaching a texture on my object, I multiply the ambient by the light color and I get a dark object when no light, and illuminated properly when a light source is activated.
The problem is that when I attach a texture and multiply it by ambient and light color I get a transparent object that shows up only when a light source is activated, and you can even see through the object while it is illuminated!
I've been trying several codes snippets from the internet but I always get the same result. What I'm doing wrong here? I'm desperate...
The application is developed on Android.
Here is my Vertex Shader:
uniform mat4 uMVPMatrix;
uniform mat4 normalMatrix;
// eye pos
uniform vec3 eyePos;
// position and normal of the vertices
attribute vec4 aPosition;
attribute vec3 aNormal;
// texture variables
uniform float hasTexture;
varying float tex;
attribute vec2 textureCoord;
varying vec2 tCoord;
// lighting
uniform vec4 lightPos;
uniform vec4 lightColor;
// material
uniform vec4 matAmbient;
uniform vec4 matDiffuse;
uniform vec4 matSpecular;
uniform float matShininess;
// normals to pass on
varying vec3 vNormal;
varying vec3 EyespaceNormal;
varying vec3 lightDir, eyeVec;
void main() {
// pass on texture variables
tex = hasTexture;
tCoord = textureCoord;
// normal
EyespaceNormal = vec3(normalMatrix * vec4(aNormal, 1.0));
// the vertex position
vec4 position = uMVPMatrix * aPosition;
// light dir
lightDir = lightPos.xyz - position.xyz;
eyeVec = -position.xyz;
gl_Position = uMVPMatrix * aPosition;
}
And here is my Fragment shader:
precision mediump float;
// texture variables
uniform sampler2D texture1; // color texture
varying float tex;
varying vec2 tCoord;
varying vec3 vNormal;
varying vec3 EyespaceNormal;
// light
uniform vec4 lightPos;
uniform vec4 lightColor;
// material
uniform vec4 matAmbient;
uniform vec4 matDiffuse;
uniform vec4 matSpecular;
uniform float matShininess;
// eye pos
uniform vec3 eyePos;
// from vertex s
varying vec3 lightDir, eyeVec;
void main() {
vec4 b = lightColor;
vec4 c = matAmbient;
vec4 d = matDiffuse;
vec4 e = matSpecular;
vec3 g = eyePos;
float f = matShininess;
vec3 N = normalize(EyespaceNormal);
vec3 E = normalize(eyeVec);
vec3 L = normalize(lightDir);
// Reflect the vector. Use this or reflect(incidentV, N);
vec3 reflectV = reflect(-L, N);
// Get lighting terms
vec4 ambientTerm;
if (tex >= 1.0) {
ambientTerm = texture2D(texture1, tCoord);
}
else
ambientTerm = matAmbient * lightColor;
vec4 diffuseTerm = matDiffuse * max(dot(N, L), 0.0);
vec4 specularTerm = matSpecular * pow(max(dot(reflectV, E), 0.0), matShininess);
gl_FragColor = ambientTerm * diffuseTerm + specularTerm;
}
Thanks in advance.

OK I found it, thanks to JPD002, I was revising the shader again, and I found out that it has to be
vec4 diffuseTerm = matDiffuse * max(dot(N, L), 0.0);
vec4 specularTerm = matSpecular * pow(max(dot(reflectV, E), 1.0), matShininess);
Thanks JDP002, it is always good to have 4 eyes on code rather than 2 =D