Shader: question on android error

Comments

• mertocan Member

  June 2016

  Can you share all code of glsl file ?

  My Games. Mert Can KURUM

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• pie Member

  June 2016

  of course, I had to clean it up a little

  uniform lowp sampler2D g_Texture; uniform lowp vec4 g_Color;       #define NUM_LIGHTS 2 uniform mediump vec4 lightPos[NUM_LIGHTS];   //attenuation coefficients uniform vec3 Falloff = vec3(0.1,0.02,0);     varying highp vec2 texCoord; varying mediump vec2 position;     void main() {     //Common data //Grab the main pixel color from the classic texture lowp vec3 color0 = texture2D(g_Texture, texCoord).rgb;   //Set the specular (i.e. "shine") color to 30% gray lowp vec3 color1 = vec3(0.3, 0.3, 0.3);   //Grab the normal vector from the right part of the texture: //-Displace by 0.5 to the right in normalized coordinates (1=full texture width) //-Convert RGB (range 0->1) to XYZ (range -1 -> 1) mediump vec3 normal = texture2D(g_Texture, texCoord + vec2(0.5, 0.0)).rgb * 2.0 - 1.0;   lowp vec3 lightContributions=vec3(0,0,0); int index; for (index = 0; index <= NUM_LIGHTS; index++) // for all light sources { //Compute light direction, assuming light distance of altitude units. y inverted as in spriteilluminator vec3 LightDirection = vec3(lightPos[index].x,-lightPos[index].y, 30) - vec3(position.x,-position.y, 0);   //Determine distance (used for attenuation) BEFORE we normalize our LightDir float D = length(LightDirection);   //normalize lightdir mediump vec3 lightDir = normalize(LightDirection);   //Compute the light direction as if light was two times further (for specular) mediump vec3 halfdir = normalize(normalize(lightDir) + vec3(0, 0, 1));   //Compute diffuse factor: normal and lightDir colinear -> 1, perpendicular -> 0 lowp float diff = max(0.1, dot(normal, lightDir));   //Compute specular factor the same way, but with exponential scale mediump float nh = max(0.1, dot(normal, halfdir)); mediump float spec = pow(nh, 10.0);   //calculate attenuation float Attenuation = 1.0 / ( Falloff.x + (Falloff.y*D) + (Falloff.z*D*D) );     lightContributions= lightContributions+ (color0 * diff + color1 * spec) *Attenuation;     }                 gl_FragColor = g_Color * vec4(lightContributions.rgb, 1);   }

  It's the "multi light" shader made by @hgy29, with some small additions from here:
  https://github.com/mattdesl/lwjgl-basics/wiki/ShaderLesson6
  
  I thought the error was from Falloff = vec3(0.1,0.02,0); but I have the same error using
  Falloff = vec3(0.1,0.2,0);
  Thank you
  
  

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• mertocan Member

  June 2016 Accepted Answer

  Can you try again after replacing highp with mediump ?

  My Games. Mert Can KURUM

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• hgy29 Maintainer

  June 2016 Accepted Answer

  @pie,
  
  You simply can't give a value to a uniform, uniforms take their value from outside the shader (ie C code or lua).

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• pie Member

  June 2016

  Thank you @hgy29, I missed that
  For the records, I was also missing precision declarations on other variables: ie
  mediump float D = length(LightDirection);

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