GLSL着色器整数参数解释为float

Question

我有以下（有点旧）GLSL着色器。

/**
 * @file   YCbCr.glsl
 * @author gga
 * @date   Thu Jul  5 22:50:08 2007
 * 
 * @brief    simple YCbCr texture with 3D lut shader
 * 
 */


// Images
uniform sampler2D YImage;
uniform sampler2D UImage;
uniform sampler2D VImage;
uniform sampler3D lut;

// Standard controls
uniform float gain;
uniform float gamma;
uniform int   channel;

// Interlaced/Checkerboard controls (don't work)
uniform int mask;
uniform int mask_value;
uniform int height;
uniform int width;

// Normalization variables
uniform bool  premult;
uniform bool  unpremult;
uniform bool  enableNormalization;
uniform float normMin;
uniform float normSpan;

// YCbCr variables
uniform bool  coeffs;  // Use fed coefficients instead of builtin ones
uniform vec3  Koff;
uniform vec3  Kr;
uniform vec3  Kg;
uniform vec3  Kb;

// Lut variables
uniform bool  enableLut;
uniform bool  lutF;
uniform float lutMin;
uniform float lutMax;
uniform float lutM;
uniform float lutT;


void main()
{ 
  //
  // Sample luminance and chroma, convert to RGB. 
  //
  vec4 c;   
  vec3 pre;
  vec2 uv = gl_TexCoord[0];
  pre.r = texture2D(YImage, uv.st).r;  // Y
  pre.g = texture2D(UImage, uv.st).r;  // U
  pre.b = texture2D(VImage, uv.st).r;  // V

  if ( coeffs )
  {
    pre += Koff;

    c.r = dot(Kr, pre);
    c.g = dot(Kg, pre);
    c.b = dot(Kb, pre);
    c.a = 1.0;
  }
  else
  {
      vec3 yuv;

      yuv.r = 1.1643 * ( pre.r - 0.0625 );
      yuv.g = pre.g - 0.5;
      yuv.b = pre.b - 0.5;

      c.r = yuv.r + 1.5958 * yuv.b;
      c.g = yuv.r - 0.39173 * yuv.g - 0.81290 * yuv.b;
      c.b = yuv.r + 2.017 * yuv.g;
  }

  vec2 tc = gl_TexCoord[0].st;
  c.rgb = clamp( c.rgb, 0.0, 1.0 );
  c.a = 1.0;
  int x = 0;

  if ( mask == 1 )  // even odd rows
  {
      float f = tc.y * height;
      x = int( mod( f, 2 ) );
      if ( c.a == 0.0 ) c.a = 1.0;
  }
  else if ( mask == 2 ) // even odd columns
  {
      float f2 = tc.x * width;
      x = int( mod( f2, 2 ) );
      if ( c.a == 0.0 ) c.a = 1.0;
  }
  else if ( mask == 3 ) // checkerboard
  {
      float f = tc.y * height;
      float f2 = tc.x * width;
      x = int( mod( floor( f2 ) + floor( f ), 2 ) < 1 );
      if ( c.a == 0.0 ) c.a = 1.0;
  }

  if ( x == mask_value )
  {
      c.r = c.g = c.b = c.a = 0.0;
  }

  //
  // Apply normalization
  //
  if (enableNormalization)
    {
      c.rgb = (c.rgb - normMin) / normSpan;
    }

  //
  // Apply 3D color lookup table (in log space).
  //
  if (enableLut)
    {
      c.rgb = lutT + lutM * log( clamp(c.rgb, lutMin, lutMax) );
      c.rgb = exp( texture3D(lut, c.rgb).rgb ); 
    }

  if ( unpremult )
  {
    c.rgb /= c.a;
  }

  //
  // Apply gain 
  //
  c.rgb *= gain;

  //
  // Apply video gamma correction.
  // 
  c.r = pow( c.r, gamma );
  c.g = pow( c.g, gamma );
  c.b = pow( c.b, gamma );

  //
  // Apply channel selection
  // 
  if ( channel == 1 )
    {
      c.rgb = c.rrr;
    }
  else if ( channel == 2 )
    {
      c.rgb = c.ggg;
    }
  else if ( channel == 3 )
    {
      c.rgb = c.bbb;
    }
  else if ( channel == 4 )
    {
      c.rgb = c.aaa;
    }
  else if ( channel == 5 )
    {
      c.r *= 0.5;
      c.r += c.a * 0.5;
    }
  else if ( channel == 6 )
    {
      c.rgb = vec3( (c.r + c.g + c.b) / 3.0 );
    }

  if ( premult )
  {
      c.rgb *= c.a;
  }

  gl_FragColor = c;
} 

我的问题是4个int参数（mask，mask_value，height，width）被解释为float。也就是说，如果我调用glUniform1i，我会收到错误。但是，如果我将参数称为glUniform1f它可以工作。请注意，channel参数被正确地视为整数。这似乎是着色器编译器中的一个错误。有人可以帮我解决这个问题（也许是在使着色器更新的过程中）？

以下是设置制服的C ++代码：

  void GLShader::setUniform( const GLint location, const GLint x  )
  {
      glUniform1i( location, x );
  }

  void GLShader::setUniform( const GLint location,
                 const int x, const int y )
  {
      glUniform2i( location, x, y );
  }

  void GLShader::setUniform( const GLint location,
                 const int x, const int y, const int z )
  {
      glUniform3i( location, x, y, z );
  }


  void GLShader::setUniform( const GLint location,
                 const int x, const int y, 
                 const int z, const int w  )
  {
      glUniform4i( location, x, y, z, w );
  }

  void GLShader::setUniform( const char* uniform, 
                 const int x )
  {
    if ( _program )
      {
    GLint location = glGetUniformLocation( _program, uniform );
    // location is valid here, not -1
    CHECK_GL;
    setUniform( location, x );
    CHECK_GL;
      }
    else if ( _frag_target == GL_FRAGMENT_PROGRAM_NV )
      {
    glProgramNamedParameter4fNV( _frag_shader, strlen(uniform), 
                     (GLubyte *) uniform,
                     float(x), 0.f, 0.f, 0.f );
    CHECK_GL;
      }
    else if ( _frag_target == GL_FRAGMENT_PROGRAM_ARB )
      {
    GLint location = uniform_location( uniform );
    CHECK_GL;
    glProgramLocalParameter4fARB( _frag_target, location, 
                      float(x), 0.f, 0.f, 0.f);
    CHECK_GL;
      }
  }

设置值的调用（所有变量都是int）。

    _shader->setUniform( "mask", _mask );
    CHECK_GL;
    _shader->setUniform( "mask_value", _mask_value );
    CHECK_GL;
    _shader->setUniform( "width", _width );
    CHECK_GL;
    _shader->setUniform( "height", _height );
    CHECK_GL;