TypeScript one_dimensional_texture_access.OneDimensionalTextureAccessHelper類代碼示例

  fragmentShaderTest(6, tester => {
    let {gl, builder} = tester;
    const dataType = DataType.UINT32;
    const numComponents = 1;
    const format = new OneDimensionalTextureFormat();
    const layout = new OneDimensionalTextureLayout();
    compute1dTextureFormat(format, dataType, numComponents);

    const data = new Uint32Array(dataLength);
    for (let i = 0; i < data.length; ++i) {
      data[i] = i;
    }

    setLayout(layout, gl, format.texelsPerElement);

    const accessHelper = new OneDimensionalTextureAccessHelper('textureAccess');
    const textureUnitSymbol = Symbol('textureUnit');
    accessHelper.defineShader(builder);
    builder.addUniform('highp float', 'uOffset');
    builder.addUniform('highp vec4', 'uExpected');
    builder.addTextureSampler2D('uSampler', textureUnitSymbol);
    builder.addFragmentCode(
        accessHelper.getAccessor('readValue', 'uSampler', dataType, numComponents));
    builder.addFragmentCode(glsl_unnormalizeUint8);
    builder.addFragmentCode(glsl_uintleToFloat);
    builder.addOutputBuffer('vec4', 'v4f_fragData0', 0);
    builder.addOutputBuffer('vec4', 'v4f_fragData1', 1);
    builder.addOutputBuffer('vec4', 'v4f_fragData2', 2);
    builder.addOutputBuffer('vec4', 'v4f_fragData3', 3);
    builder.addOutputBuffer('vec4', 'v4f_fragData4', 4);
    builder.addOutputBuffer('vec4', 'v4f_fragData5', 5);
    builder.setFragmentMain(`
uint32_t value = readValue(uOffset);
v4f_fragData4 = packFloatIntoVec4(uintleToFloat(value.value.xyz));
v4f_fragData5 = packFloatIntoVec4(all(equal(value.value, uExpected)) ? 1.0 : 0.0);
value.value = unnormalizeUint8(value.value);
v4f_fragData0 = packFloatIntoVec4(value.value.x);
v4f_fragData1 = packFloatIntoVec4(value.value.y);
v4f_fragData2 = packFloatIntoVec4(value.value.z);
v4f_fragData3 = packFloatIntoVec4(value.value.w);
`);

    tester.build();
    let {shader} = tester;
    shader.bind();

    accessHelper.setupTextureLayout(gl, shader, layout);

    const textureUnit = shader.textureUnit(textureUnitSymbol);
    let texture = gl.createTexture();
    tester.registerDisposer(() => {
      gl.deleteTexture(texture);
    });
    gl.bindTexture(gl.TEXTURE_2D, texture);
    setOneDimensionalTextureData(gl, layout, format, data);
    gl.bindTexture(gl.TEXTURE_2D, null);

    function testOffset(x: number) {
      let value = data[x];
      gl.uniform1f(shader.uniform('uOffset'), x);
      gl.uniform4fv(shader.uniform('uExpected'), setVec4FromUint32(new Float32Array(4), value));

      gl.activeTexture(gl.TEXTURE0 + textureUnit);
      gl.bindTexture(gl.TEXTURE_2D, texture);
      tester.execute();
      gl.bindTexture(gl.TEXTURE_2D, null);

      let actual = new Float32Array(4);
      let expected = new Float32Array(4);
      for (let i = 0; i < 4; ++i) {
        actual[i] = tester.readFloat(i);
        expected[i] = (value >>> (8 * i)) & 0xFF;
      }
      for (let i = 0; i < 4; ++i) {
        expect(actual[i]).toBe(
            expected[i],
            `offset = ${x}, value = ${x}, actual = ${Array.from(actual)}, expected = ${
                Array.from(expected)}`);
      }
      expect(tester.readFloat(4))
          .toBe(value, `uint24le value != expected, offset = ${x}, value = ${x}`);
      expect(tester.readFloat(5))
          .toBe(1.0, `uExpected != value in shader, offset = ${x}, value = ${x}`);
    }

    testOffset(255 /*+ 256 * 256 * 9*/);
    for (let i = 0; i < 100; ++i) {
      testOffset(i);
    }

    const COUNT = 100;
    for (let i = 0; i < COUNT; ++i) {
      let offset = Math.floor(Math.random() * data.length);
      testOffset(offset);
    }
  });

  defineShader(builder: ShaderBuilder) {
    super.defineShader(builder);
    let {textureAccessHelper} = this;
    textureAccessHelper.defineShader(builder);
    builder.addFragmentCode(
        textureAccessHelper.getAccessor('readVolumeData', 'uVolumeChunkSampler', this.dataType));

    let {numChannels} = this;
    if (numChannels > 1) {
      builder.addUniform('highp float', 'uChannelStride');
      builder.addFragmentCode(`
float getChannelOffset(int channelIndex) {
  return float(channelIndex) * uChannelStride;
}
`);
    } else {
      builder.addFragmentCode(`float getChannelOffset(int channelIndex) { return 0.0; }`);
    }

    builder.addFragmentCode(`
float getIndexIntoChunk (int channelIndex) {
  vec3 chunkDataPosition = getPositionWithinChunk();
  return chunkDataPosition.x + uChunkDataSize.x * (chunkDataPosition.y + uChunkDataSize.y * chunkDataPosition.z) + getChannelOffset(channelIndex);
}
`);
    const shaderType = getShaderType(this.dataType);
    builder.addFragmentCode(`
${shaderType} getDataValue (int channelIndex) {
  return readVolumeData(getIndexIntoChunk(channelIndex));
}
`);
  }

  defineShader(builder: ShaderBuilder) {
    super.defineShader(builder);
    this.textureAccessHelper.defineShader(builder);
    let local = (x: string) => 'compressedSegmentationChunkFormat_' + x;
    builder.addUniform('highp vec3', 'uSubchunkGridSize');
    builder.addUniform('highp vec3', 'uSubchunkSize');
    builder.addFragmentCode(glsl_getFortranOrderIndexFromNormalized);
    const {dataType} = this;
    const glslType = GLSL_TYPE_FOR_DATA_TYPE.get(dataType);

    if (dataType === DataType.UINT64) {
      builder.addFragmentCode(glsl_uint64);
    } else {
      builder.addFragmentCode(glsl_uint32);
    }

    let fragmentCode = `
vec4 ${local('readTextureValue')}(float offset) {
  vec4 result;
  ${this.textureAccessHelper.readTextureValue}(uVolumeChunkSampler, offset, result);
  return result;
}
float ${local('getChannelOffset')}(int channelIndex) {
  if (channelIndex == 0) {
    return ${this.numChannels}.0;
  }
  vec4 v = ${local('readTextureValue')}(float(channelIndex));
  return v.x * 255.0 + v.y * 255.0 * 256.0 + v.z * 255.0 * 256.0 * 256.0;
}
${glslType} getDataValue (int channelIndex) {
  vec3 chunkPosition = getPositionWithinChunk();

  // TODO: maybe premultiply this and store as uniform.
  vec3 subchunkGridPosition = floor(chunkPosition / uSubchunkSize);
  float subchunkGridOffset = getFortranOrderIndex(subchunkGridPosition, uSubchunkGridSize);

  float channelOffset = ${local('getChannelOffset')}(channelIndex);

  // TODO: Maybe just combine this offset into subchunkGridStrides.
  float subchunkHeaderOffset = subchunkGridOffset * 2.0 + channelOffset;

  vec4 subchunkHeader0 = ${local('readTextureValue')}(subchunkHeaderOffset);
  vec4 subchunkHeader1 = ${local('readTextureValue')}(subchunkHeaderOffset + 1.0);

  float outputValueOffset = dot(subchunkHeader0.xyz, vec3(255, 256 * 255, 256 * 256 * 255)) + channelOffset;
  float encodingBits = subchunkHeader0[3] * 255.0;
  if (encodingBits > 0.0) {
    vec3 subchunkPosition = floor(min(chunkPosition - subchunkGridPosition * uSubchunkSize, uSubchunkSize - 1.0));
    float subchunkOffset = getFortranOrderIndex(subchunkPosition, uSubchunkSize);
    highp float encodedValueBaseOffset = dot(subchunkHeader1.xyz, vec3(255.0, 256.0 * 255.0, 256.0 * 256.0 * 255.0)) + channelOffset;
    highp float encodedValueOffset = floor(encodedValueBaseOffset + subchunkOffset * encodingBits / 32.0);
    vec4 encodedValue = ${local('readTextureValue')}(encodedValueOffset);
    float wordOffset = mod(subchunkOffset * encodingBits, 32.0);
    // If the value is in the first byte, then 0 <= wordOffset < 8.
    // We need to mod by 2**encodedBits
    float wordShifter = pow(2.0, -wordOffset);
    float encodedValueMod = pow(2.0, encodingBits);
    float encodedValueShifted;
    if (wordOffset < 16.0) {
      encodedValueShifted = dot(encodedValue.xy, vec2(255.0, 255.0 * 256.0));
    } else {
      encodedValueShifted = dot(encodedValue.zw, vec2(255.0 * 256.0 * 256.0, 255.0 * 256.0 * 256.0 * 256.0));
    }
    encodedValueShifted = floor(encodedValueShifted * wordShifter);
    float decodedValue = mod(encodedValueShifted, encodedValueMod);
    outputValueOffset += decodedValue * ${this.dataType === DataType.UINT64 ? '2.0' : '1.0'};
  }
  ${glslType} result;
`;
    if (dataType === DataType.UINT64) {
      fragmentCode += `
  result.low = ${local('readTextureValue')}(outputValueOffset);
  result.high = ${local('readTextureValue')}(outputValueOffset+1.0);
`;
    } else {
      fragmentCode += `
  result.value = ${local('readTextureValue')}(outputValueOffset);
`;
    }
    fragmentCode += `
  return result;
}
`;
    builder.addFragmentCode(fragmentCode);
  }

 /**
  * Called each time textureLayout changes while drawing chunks.
  */
 setupTextureLayout(gl: GL, shader: ShaderProgram, textureLayout: TextureLayout) {
   gl.uniform3fv(shader.uniform('uSubchunkGridSize'), textureLayout.subchunkGridSize);
   this.textureAccessHelper.setupTextureLayout(gl, shader, textureLayout);
 }

 /**
  * Called each time textureLayout changes while drawing chunks.
  */
 setupTextureLayout(gl: GL, shader: ShaderProgram, textureLayout: TextureLayout) {
   if (this.numChannels > 1) {
     gl.uniform1f(shader.uniform('uChannelStride'), textureLayout.channelStride);
   }
   this.textureAccessHelper.setupTextureLayout(gl, shader, textureLayout);
 }

  defineShader(builder: ShaderBuilder) {
    super.defineShader(builder);
    this.textureAccessHelper.defineShader(builder);

    let {numChannels} = this;
    if (numChannels > 1) {
      builder.addUniform('highp float', 'uChannelStride');
      builder.addFragmentCode(`
float getChannelOffset(int channelIndex) {
  return float(channelIndex) * uChannelStride;
}
`);
    } else {
      builder.addFragmentCode(`float getChannelOffset(int channelIndex) { return 0.0; }`);
    }

    builder.addFragmentCode(`
float getIndexIntoChunk (int channelIndex) {
  vec3 chunkDataPosition = getPositionWithinChunk();
  return chunkDataPosition.x + uChunkDataSize.x * (chunkDataPosition.y + uChunkDataSize.y * chunkDataPosition.z) + getChannelOffset(channelIndex);
}
`);
    switch (this.dataType) {
      case DataType.UINT8:
        builder.addFragmentCode(glsl_uint8);
        builder.addFragmentCode(`
uint8_t getDataValue (int channelIndex) {
  uint8_t result;
  vec4 temp;
  ${this.textureAccessHelper.readTextureValue}(uVolumeChunkSampler, getIndexIntoChunk(channelIndex), temp);
  result.value = temp.x;
  return result;
}
`);
        break;
      case DataType.FLOAT32:
        builder.addFragmentCode(glsl_float);
        builder.addFragmentCode(`
float getDataValue (int channelIndex) {
  vec4 temp;
  ${this.textureAccessHelper.readTextureValue}(uVolumeChunkSampler, getIndexIntoChunk(channelIndex), temp);
  return temp.x;
}
`);
        break;
      case DataType.UINT16:
        builder.addFragmentCode(glsl_uint16);
        builder.addFragmentCode(`
uint16_t getDataValue (int channelIndex) {
  uint16_t result;
  vec4 temp;
  ${this.textureAccessHelper.readTextureValue}(uVolumeChunkSampler, getIndexIntoChunk(channelIndex), temp);
  result.value = temp.xw;
  return result;
}
`);
        break;
      case DataType.UINT32:
        builder.addFragmentCode(glsl_uint32);
        builder.addFragmentCode(`
uint32_t getDataValue (int channelIndex) {
  uint32_t result;
  ${this.textureAccessHelper.readTextureValue}(uVolumeChunkSampler, getIndexIntoChunk(channelIndex), result.value);
  return result;
}
`);
        break;
      case DataType.UINT64:
        builder.addFragmentCode(glsl_uint64);
        builder.addFragmentCode(`
uint64_t getDataValue (int channelIndex) {
  uint64_t result;
  ${this.textureAccessHelper.readTextureValue}(uVolumeChunkSampler, getIndexIntoChunk(channelIndex), result.low, result.high);
  return result;
}
`);
        break;
    }
  }