getByteLength static method

num getByteLength(num width, num height, int format, int type,)

Determines how many bytes must be used to represent the texture.

@param {number} width - The width of the texture. @param {number} height - The height of the texture. @param {number} format - The texture's format. @param {number} type - The texture's type. @return {number} The byte length.

Implementation

static num getByteLength(num width,num height, int format, int type ) {

  final TypeByteLength typeByteLength = getTextureTypeByteLength( type );

  switch ( format ) {

    // https://registry.khronos.org/OpenGL-Refpages/es3.0/html/glTexImage2D.xhtml
    case AlphaFormat:
      return width * height;
    case LuminanceFormat:
      return width * height;
    case LuminanceAlphaFormat:
      return width * height * 2;
    case RedFormat:
      return ( ( width * height ) / typeByteLength.components ) * typeByteLength.byteLength;
    case RedIntegerFormat:
      return ( ( width * height ) / typeByteLength.components ) * typeByteLength.byteLength;
    case RGFormat:
      return ( ( width * height * 2 ) / typeByteLength.components ) * typeByteLength.byteLength;
    case RGIntegerFormat:
      return ( ( width * height * 2 ) / typeByteLength.components ) * typeByteLength.byteLength;
    case RGBFormat:
      return ( ( width * height * 3 ) / typeByteLength.components ) * typeByteLength.byteLength;
    case RGBAFormat:
      return ( ( width * height * 4 ) / typeByteLength.components ) * typeByteLength.byteLength;
    case RGBAIntegerFormat:
      return ( ( width * height * 4 ) / typeByteLength.components ) * typeByteLength.byteLength;

    // https://registry.khronos.org/webgl/extensions/WEBGL_compressed_texture_s3tc_srgb/
    case RGB_S3TC_DXT1_Format:
    case RGBA_S3TC_DXT1_Format:
      return ( ( width + 3 ) / 4 ).floor() * ( ( height + 3 ) / 4 ).floor() * 8;
    case RGBA_S3TC_DXT3_Format:
    case RGBA_S3TC_DXT5_Format:
      return ( ( width + 3 ) / 4 ).floor() * ( ( height + 3 ) / 4 ).floor() * 16;

    // https://registry.khronos.org/webgl/extensions/WEBGL_compressed_texture_pvrtc/
    case RGB_PVRTC_2BPPV1_Format:
    case RGBA_PVRTC_2BPPV1_Format:
      return ( math.max( width, 16 ) * math.max( height, 8 ) ) / 4;
    case RGB_PVRTC_4BPPV1_Format:
    case RGBA_PVRTC_4BPPV1_Format:
      return ( math.max( width, 8 ) * math.max( height, 8 ) ) / 2;

    // https://registry.khronos.org/webgl/extensions/WEBGL_compressed_texture_etc/
    case RGB_ETC1_Format:
    case RGB_ETC2_Format:
      return ( ( width + 3 ) / 4 ).floor() * ( ( height + 3 ) / 4 ).floor() * 8;
    case RGBA_ETC2_EAC_Format:
      return ( ( width + 3 ) / 4 ).floor() * ( ( height + 3 ) / 4 ).floor() * 16;

    // https://registry.khronos.org/webgl/extensions/WEBGL_compressed_texture_astc/
    case RGBA_ASTC_4x4_Format:
      return ( ( width + 3 ) / 4 ).floor() * ( ( height + 3 ) / 4 ).floor() * 16;
    case RGBA_ASTC_5x4_Format:
      return ( ( width + 4 ) / 5 ).floor() * ( ( height + 3 ) / 4 ).floor() * 16;
    case RGBA_ASTC_5x5_Format:
      return ( ( width + 4 ) / 5 ).floor() * ( ( height + 4 ) / 5 ).floor() * 16;
    case RGBA_ASTC_6x5_Format:
      return ( ( width + 5 ) / 6 ).floor() * ( ( height + 4 ) / 5 ).floor() * 16;
    case RGBA_ASTC_6x6_Format:
      return ( ( width + 5 ) / 6 ).floor() * ( ( height + 5 ) / 6 ).floor() * 16;
    case RGBA_ASTC_8x5_Format:
      return ( ( width + 7 ) / 8 ).floor() * ( ( height + 4 ) / 5 ).floor() * 16;
    case RGBA_ASTC_8x6_Format:
      return ( ( width + 7 ) / 8 ).floor() * ( ( height + 5 ) / 6 ).floor() * 16;
    case RGBA_ASTC_8x8_Format:
      return ( ( width + 7 ) / 8 ).floor() * ( ( height + 7 ) / 8 ).floor() * 16;
    case RGBA_ASTC_10x5_Format:
      return ( ( width + 9 ) / 10 ).floor() * ( ( height + 4 ) / 5 ).floor() * 16;
    case RGBA_ASTC_10x6_Format:
      return ( ( width + 9 ) / 10 ).floor() * ( ( height + 5 ) / 6 ).floor() * 16;
    case RGBA_ASTC_10x8_Format:
      return ( ( width + 9 ) / 10 ).floor() * ( ( height + 7 ) / 8 ).floor() * 16;
    case RGBA_ASTC_10x10_Format:
      return ( ( width + 9 ) / 10 ).floor() * ( ( height + 9 ) / 10 ).floor() * 16;
    case RGBA_ASTC_12x10_Format:
      return ( ( width + 11 ) / 12 ).floor() * ( ( height + 9 ) / 10 ).floor() * 16;
    case RGBA_ASTC_12x12_Format:
      return ( ( width + 11 ) / 12 ).floor() * ( ( height + 11 ) / 12 ).floor() * 16;

    // https://registry.khronos.org/webgl/extensions/EXT_texture_compression_bptc/
    case RGBA_BPTC_Format:
    case RGB_BPTC_SIGNED_Format:
    case RGB_BPTC_UNSIGNED_Format:
      return ( width / 4 ).ceil() * ( height / 4 ).ceil() * 16;

    // https://registry.khronos.org/webgl/extensions/EXT_texture_compression_rgtc/
    case RED_RGTC1_Format:
    case SIGNED_RED_RGTC1_Format:
      return ( width / 4 ).ceil() *  (height / 4 ).ceil() * 8;
    case RED_GREEN_RGTC2_Format:
    case SIGNED_RED_GREEN_RGTC2_Format:
      return ( width / 4 ).ceil() * ( height / 4 ).ceil() * 16;

  }

  throw('Unable to determine texture byte length for ${format} format.',);
}