The following table lists the intrinsic functions available in HLSL. Each function has a brief description, and a link to a reference page that has more detail about the input argument and return type.

| Name | Syntax | Description |
| abs | abs(x) | Absolute value (per component). |
| acos | acos(x) | Returns the arccosine of each component of x. |
| all | all(x) | Test if all components of x are nonzero. |
| any | any(x) | Test if any component of x is nonzero. |
| asfloat | asfloat(x) | Convert the input type to a float. |
| asin | asin(x) | Returns the arcsine of each component of x. |
| asint | asint(x) | Convert the input type to an integer. |
| asuint | asuint(x) | Convert the input type to an unsigned integer. |
| atan | atan(x) | Returns the arctangent of x. |
| atan2 | atan2(y, x) | Returns the arctangent of of two values (x,y). |
| ceil | ceil(x) | Returns the smallest integer which is greater than or equal to x. |
| clamp | clamp(x, min, max) | Clamps x to the range [min, max]. |
| clip | clip(x) | Discards the current pixel, if any component of x is less than zero. |
| cos | cos(x) | Returns the cosine of x. |
| cosh | cosh(x) | Returns the hyperbolic cosine of x. |
| cross | cross(x, y) | Returns the cross product of two 3D vectors. |
| D3DCOLORtoUBYTE4 | D3DCOLORtoUBYTE4(x) | Swizzles and scales components of the 4D vector x to compensate for the lack of UBYTE4 support in some hardware. |
| ddx | ddx(x) | Returns the partial derivative of x with respect to the screen-space x-coordinate. |
| ddy | ddy(x) | Returns the partial derivative of x with respect to the screen-space y-coordinate. |
| degrees | degrees(x) | Converts x from radians to degrees. |
| determinant | determinant(m) | Returns the determinant of the square matrix m. |
| distance | distance(x, y) | Returns the distance between two points. |
| dot | dot(x, y) | Returns the dot product of two vectors. |
| exp | exp(x) | Returns the base-e exponent. |
| exp2 | exp2(x) | Base 2 exponent (per component). |
| faceforward | faceforward(n, i, ng) | Returns -n * sign(•(i, ng)). |
| floor | floor(x) | Returns the greatest integer which is less than or equal to x. |
| fmod | fmod(x, y) | Returns the floating point remainder of x/y. |
| frac | frac(x) | Returns the fractional part of x. |
| frexp | frexp(x, exp) | Returns the mantissa and exponent of x. |
| fwidth | fwidth(x) | Returns abs(ddx(x)) + abs(ddy(x)) |
| GetRenderTargetSampleCount | GetRenderTargetSampleCount() | Returns the number of render-target samples. |
| GetRenderTargetSamplePosition | GetRenderTargetSamplePosition(x) | Returns a sample position (x,y) for a given sample index. |
| isfinite | isfinite(x) | Returns true if x is finite, false otherwise. |
| isinf | isinf(x) | Returns true if x is +INF or -INF, false otherwise. |
| isnan | isnan(x) | Returns true if x is NAN or QNAN, false otherwise. |
| ldexp | ldexp(x, exp) | Returns x * 2exp |
| length | length(v) | Returns the length of the vector v. |
| lerp | lerp(x, y, s) | Returns x + s(y - x). |
| lit | lit(n • l, n • h, m) | Returns a lighting vector (ambient, diffuse, specular, 1) |
| log | log(x) | Returns the base-e logarithm of x. |
| log10 | log10(x) | Returns the base-10 logarithm of x. |
| log2 | log2(x) | Returns the base-2 logarithm of x. |
| max | max(x, y) | Selects the greater of x and y. |
| min | min(x, y) | Selects the lesser of x and y. |
| modf | modf(x, out ip) | Splits the value x into fractional and integer parts. |
| mul | mul(x, y) | Performs matrix multiplication using x and y. |
| noise | noise(x) | Generates a random value using the Perlin-noise algorithm. |
| normalize | normalize(x) | Returns a normalized vector. |
| pow | pow(x, y) | Returns x^y. |
| radians | radians(x) | Converts x from degrees to radians. |
| reflect | reflect(i, n) | Returns a reflection vector. |
| refract | refract(i, n, R) | Returns the refraction vector. |
| round | round(x) | Rounds x to the nearest integer |
| rsqrt | rsqrt(x) | Returns 1 / sqrt(x) |
| saturate | saturate(x) | Clamps x to the range [0, 1] |
| sign | sign(x) | Computes the sign of x. |
| sin | sin(x) | Returns the sine of x |
| sincos | sincos(x, out s, out c) | Returns the sine and cosine of x. |
| sinh | sinh(x) | Returns the hyperbolic sine of x |
| smoothstep | smoothstep(min, max, x) | Returns a smooth Hermite interpolation between 0 and 1. |
| sqrt | sqrt(x) | Square root (per component) |
| step | step(a, x) | Returns (x >= a) ? 1 : 0 |
| tan | tan(x) | Returns the tangent of x |
| tanh | tanh(x) | Returns the hyperbolic tangent of x |
| tex1D | tex1D(s, t) | 1D texture lookup. |
| tex1Dbias | tex1Dbias(s, t) | 1D texture lookup with bias. |
| tex1Dgrad | tex1Dgrad(s, t, ddx, ddy) | 1D texture lookup with a gradient. |
| tex1Dlod | tex1Dlod(s, t) | 1D texture lookup with LOD. |
| tex1Dproj | tex1Dproj(s, t) | 1D texture lookup with projective divide. |
| tex2D | tex2D(s, t) | 2D texture lookup. |
| tex2Dbias | tex2Dbias(s, t) | 2D texture lookup with bias. |
| tex2Dgrad | tex2Dgrad(s, t, ddx, ddy) | 2D texture lookup with a gradient. |
| tex2Dlod | tex2Dlod(s, t) | 2D texture lookup with LOD. |
| tex2Dproj | tex2Dproj(s, t) | 2D texture lookup with projective divide. |
| tex3D | tex3D(s, t) | 3D texture lookup. |
| tex3Dbias | tex3Dbias(s, t) | 3D texture lookup with bias. |
| tex3Dgrad | tex3Dgrad(s, t, ddx, ddy) | 3D texture lookup with a gradient. |
| tex3Dlod | tex3Dlod(s, t) | 3D texture lookup with LOD. |
| tex3Dproj | tex3Dproj(s, t) | 3D texture lookup with projective divide. |
| texCUBE | texCUBE(s, t) | Cube texture lookup. |
| texCUBEbias | texCUBEbias(s, t) | Cube texture lookup with bias. |
| texCUBEgrad | texCUBEgrad(s, t, ddx, ddy) | Cube texture lookup with a gradient. |
| texCUBElod | tex3Dlod(s, t) | Cube texture lookup with LOD. |
| texCUBEproj | texCUBEproj(s, t) | Cube texture lookup with projective divide. |
| transpose | transpose(m) | Returns the transpose of the matrix m. |
| trunc | trunc(x) | Truncates floating-point value(s) to integer value(s) |

表 3-1 HLSL内置函数

|

函数名 用法

|

abs 计算输入值的绝对值。

acos 返回输入值反余弦值。

all 测试非0值。

any 测试输入值中的任何非零值。

asin 返回输入值的反正弦值。

atan 返回输入值的反正切值。

atan2 返回y/x的反正切值。

ceil 返回大于或等于输入值的最小整数。

clamp 把输入值限制在[min, max]范围内。

clip 如果输入向量中的任何元素小于0，则丢弃当前像素。

cos 返回输入值的余弦。

cosh 返回输入值的双曲余弦。

cross 返回两个3D向量的叉积。

ddx 返回关于屏幕坐标x轴的偏导数。

ddy 返回关于屏幕坐标y轴的偏导数。

degrees 弧度到角度的转换

determinant 返回输入矩阵的值。

distance 返回两个输入点间的距离。

dot 返回两个向量的点积。

exp 返回以e为底数，输入值为指数的指数函数值。

exp2 返回以2为底数，输入值为指数的指数函数值。

faceforward 检测多边形是否位于正面。

floor 返回小于等于x的最大整数。

fmod 返回a / b的浮点余数。

frac 返回输入值的小数部分。

frexp 返回输入值的尾数和指数

fwidth 返回 abs ( ddx (x) + abs ( ddy(x))。

isfinite 如果输入值为有限值则返回true，否则返回false。

isinf 如何输入值为无限的则返回true。

isnan 如果输入值为NAN或QNAN则返回true。

ldexp frexp的逆运算，返回 x * 2 ^ exp。

len / lenth 返回输入向量的长度。

lerp 对输入值进行插值计算。

lit 返回光照向量（环境光，漫反射光，镜面高光，1）。

log 返回以e为底的对数。

log10 返回以10为底的对数。

log2 返回以2为底的对数。

max 返回两个输入值中较大的一个。

min 返回两个输入值中较小的一个。

modf 把输入值分解为整数和小数部分。

mul 返回输入矩阵相乘的积。

normalize 返回规范化的向量，定义为 x / length(x)。

pow 返回输入值的指定次幂。

radians 角度到弧度的转换。

reflect 返回入射光线i对表面法线n的反射光线。

refract 返回在入射光线i，表面法线n，折射率为eta下的折射光线v。

round 返回最接近于输入值的整数。

rsqrt 返回输入值平方根的倒数。

saturate 把输入值限制到[0, 1]之间。

sign 计算输入值的符号。

sin 计算输入值的正弦值。

sincos 返回输入值的正弦和余弦值。

sinh 返回x的双曲正弦。

smoothstep 返回一个在输入值之间平稳变化的插值。

sqrt 返回输入值的平方根。

step 返回（x >= a）? 1 : 0。

tan 返回输入值的正切值。

fanh 返回输入值的双曲线切线。

transpose 返回输入矩阵的转置。

tex1D* 1D纹理查询。

tex2D* 2D纹理查询。

tex3D* 3D纹理查询。

texCUBE* 立方纹理查询。

Intrinsic Functions (DirectX HLSL)

The following table lists the intrinsic functions available in HLSL. Each function has a brief description, and a link to a reference page that has more detail about the input argument and return type.

| Name | Description | Minimum shader model |
| abs | Absolute value (per component). | 11 |
| acos | Returns the arccosine of each component of x. | 11 |
| all | Test if all components of x are nonzero. | 11 |
| AllMemoryBarrier | Blocks execution of all threads in a group until all memory accesses have been completed. | 5 |
| AllMemoryBarrierWithGroupSync | Blocks execution of all threads in a group until all memory accesses have been completed and all threads in the group have reached this call. | 5 |
| any | Test if any component of x is nonzero. | 11 |
| asdouble | Reinterprets a cast value into a double. | 5 |
| asfloat | Convert the input type to a float. | 4 |
| asin | Returns the arcsine of each component of x. | 11 |
| asint | Convert the input type to an integer. | 4 |
| asuint | Reinterprets the bit pattern of a 64-bit type to a uint. | 5 |
| asuint | Convert the input type to an unsigned integer. | 4 |
| atan | Returns the arctangent of x. | 11 |
| atan2 | Returns the arctangent of of two values (x,y). | 11 |
| ceil | Returns the smallest integer which is greater than or equal to x. | 11 |
| clamp | Clamps x to the range [min, max]. | 11 |
| clip | Discards the current pixel, if any component of x is less than zero. | 11 |
| cos | Returns the cosine of x. | 11 |
| cosh | Returns the hyperbolic cosine of x. | 11 |
| countbits | Counts the number of bits (per component) in the input integer. | 5 |
| cross | Returns the cross product of two 3D vectors. | 11 |
| D3DCOLORtoUBYTE4 | Swizzles and scales components of the 4D vector xto compensate for the lack of UBYTE4 support in some hardware. | 11 |
| ddx | Returns the partial derivative of x with respect to the screen-space x-coordinate. | 21 |
| ddx_coarse | Computes a low precision partial derivative with respect to the screen-space x-coordinate. | 5 |
| ddx_fine | Computes a high precision partial derivative with respect to the screen-space x-coordinate. | 5 |
| ddy | Returns the partial derivative of x with respect to the screen-space y-coordinate. | 21 |
| ddy_coarse | Computes a low precision partial derivative with respect to the screen-space y-coordinate. | 5 |
| ddy_fine | Computes a high precision partial derivative with respect to the screen-space y-coordinate. | 5 |
| degrees | Converts x from radians to degrees. | 11 |
| determinant | Returns the determinant of the square matrix m. | 11 |
| DeviceMemoryBarrier | Blocks execution of all threads in a group until all device memory accesses have been completed. | 5 |
| DeviceMemoryBarrierWithGroupSync | Blocks execution of all threads in a group until all device memory accesses have been completed and all threads in the group have reached this call. | 5 |
| distance | Returns the distance between two points. | 11 |
| dot | Returns the dot product of two vectors. | 1 |
| dst | Calculates a distance vector. | 5 |
| EvaluateAttributeAtCentroid | Evaluates at the pixel centroid. | 5 |
| EvaluateAttributeAtSample | Evaluates at the indexed sample location. | 5 |
| EvaluateAttributeSnapped | Evaluates at the pixel centroid with an offset. | 5 |
| exp | Returns the base-e exponent. | 11 |
| exp2 | Base 2 exponent (per component). | 11 |
| f16tof32 | Converts the float16 stored in the low-half of the uint to a float. | 5 |
| f32tof16 | Converts an input into a float16 type. | 5 |
| faceforward | Returns -n * sign(dot(i, ng)). | 11 |
| firstbithigh | Gets the location of the first set bit starting from the highest order bit and working downward, per component. | 5 |
| firstbitlow | Returns the location of the first set bit starting from the lowest order bit and working upward, per component. | 5 |
| floor | Returns the greatest integer which is less than or equal to x. | 11 |
| fmod | Returns the floating point remainder of x/y. | 11 |
| frac | Returns the fractional part of x. | 11 |
| frexp | Returns the mantissa and exponent of x. | 21 |
| fwidth | Returns abs(ddx(x)) + abs(ddy(x)) | 21 |
| GetRenderTargetSampleCount | Returns the number of render-target samples. | 4 |
| GetRenderTargetSamplePosition | Returns a sample position (x,y) for a given sample index. | 4 |
| GroupMemoryBarrier | Blocks execution of all threads in a group until all group shared accesses have been completed. | 5 |
| GroupMemoryBarrierWithGroupSync | Blocks execution of all threads in a group until all group shared accesses have been completed and all threads in the group have reached this call. | 5 |
| InterlockedAdd | Performs a guaranteed atomic add of value to the dest resource variable. | 5 |
| InterlockedAnd | Performs a guaranteed atomic and. | 5 |
| InterlockedCompareExchange | Atomically compares the input to the comparison value and exchanges the result. | 5 |
| InterlockedCompareStore | Atomically compares the input to the comparison value. | 5 |
| InterlockedExchange | Assigns value to dest and returns the original value. | 5 |
| InterlockedMax | Performs a guaranteed atomic max. | 5 |
| InterlockedMin | Performs a guaranteed atomic min. | 5 |
| InterlockedOr | Performs a guaranteed atomic or. | 5 |
| InterlockedXor | Performs a guaranteed atomic xor. | 5 |
| isfinite | Returns true if x is finite, false otherwise. | 11 |
| isinf | Returns true if x is +INF or -INF, false otherwise. | 11 |
| isnan | Returns true if x is NAN or QNAN, false otherwise. | 11 |
| ldexp | Returns x * 2exp | 11 |
| length | Returns the length of the vector v. | 11 |
| lerp | Returns x + s(y - x). | 11 |
| lit | Returns a lighting vector (ambient, diffuse, specular, 1) | 11 |
| log | Returns the base-e logarithm of x. | 11 |
| log10 | Returns the base-10 logarithm of x. | 11 |
| log2 | Returns the base-2 logarithm of x. | 11 |
| mad | Performs an arithmetic multiply/add operation on three values. | 5 |
| max | Selects the greater of x and y. | 11 |
| min | Selects the lesser of x and y. | 11 |
| modf | Splits the value x into fractional and integer parts. | 11 |
| mul | Performs matrix multiplication using x and y. | 1 |
| noise | Generates a random value using the Perlin-noise algorithm. | 11 |
| normalize | Returns a normalized vector. | 11 |
| pow | Returns xy. | 11 |
| Process2DQuadTessFactorsAvg | Generates the corrected tessellation factors for a quad patch. | 5 |
| Process2DQuadTessFactorsMax | Generates the corrected tessellation factors for a quad patch. | 5 |
| Process2DQuadTessFactorsMin | Generates the corrected tessellation factors for a quad patch. | 5 |
| ProcessIsolineTessFactors | Generates the rounded tessellation factors for an isoline. | 5 |
| ProcessQuadTessFactorsAvg | Generates the corrected tessellation factors for a quad patch. | 5 |
| ProcessQuadTessFactorsMax | Generates the corrected tessellation factors for a quad patch. | 5 |
| ProcessQuadTessFactorsMin | Generates the corrected tessellation factors for a quad patch. | 5 |
| ProcessTriTessFactorsAvg | Generates the corrected tessellation factors for a tri patch. | 5 |
| ProcessTriTessFactorsMax | Generates the corrected tessellation factors for a tri patch. | 5 |
| ProcessTriTessFactorsMin | Generates the corrected tessellation factors for a tri patch. | 5 |
| radians | Converts x from degrees to radians. | 1 |
| rcp | Calculates a fast, approximate, per-component reciprocal. | 5 |
| reflect | Returns a reflection vector. | 1 |
| refract | Returns the refraction vector. | 11 |
| reversebits | Reverses the order of the bits, per component. | 5 |
| round | Rounds x to the nearest integer | 11 |
| rsqrt | Returns 1 / sqrt(x) | 11 |
| saturate | Clamps x to the range [0, 1] | 1 |
| sign | Computes the sign of x. | 11 |
| sin | Returns the sine of x | 11 |
| sincos | Returns the sine and cosine of x. | 11 |
| sinh | Returns the hyperbolic sine of x | 11 |
| smoothstep | Returns a smooth Hermite interpolation between 0 and 1. | 11 |
| sqrt | Square root (per component) | 11 |
| step | Returns (x >= a) ? 1 : 0 | 11 |
| tan | Returns the tangent of x | 11 |
| tanh | Returns the hyperbolic tangent of x | 11 |
| tex1D(s, t) | 1D texture lookup. | 1 |
| tex1D(s, t, ddx, ddy) | 1D texture lookup. | 21 |
| tex1Dbias | 1D texture lookup with bias. | 21 |
| tex1Dgrad | 1D texture lookup with a gradient. | 21 |
| tex1Dlod | 1D texture lookup with LOD. | 31 |
| tex1Dproj | 1D texture lookup with projective divide. | 21 |
| tex2D(s, t) | 2D texture lookup. | 11 |
| tex2D(s, t, ddx, ddy) | 2D texture lookup. | 21 |
| tex2Dbias | 2D texture lookup with bias. | 21 |
| tex2Dgrad | 2D texture lookup with a gradient. | 21 |
| tex2Dlod | 2D texture lookup with LOD. | 3 |
| tex2Dproj | 2D texture lookup with projective divide. | 21 |
| tex3D(s, t) | 3D texture lookup. | 11 |
| tex3D(s, t, ddx, ddy) | 3D texture lookup. | 21 |
| tex3Dbias | 3D texture lookup with bias. | 21 |
| tex3Dgrad | 3D texture lookup with a gradient. | 21 |
| tex3Dlod | 3D texture lookup with LOD. | 31 |
| tex3Dproj | 3D texture lookup with projective divide. | 21 |
| texCUBE(s, t) | Cube texture lookup. | 11 |
| texCUBE(s, t, ddx, ddy) | Cube texture lookup. | 21 |
| texCUBEbias | Cube texture lookup with bias. | 21 |
| texCUBEgrad | Cube texture lookup with a gradient. | 21 |
| texCUBElod | Cube texture lookup with LOD. | 31 |
| texCUBEproj | Cube texture lookup with projective divide. | 21 |
| transpose | Returns the transpose of the matrix m. | 1 |
| trunc | Truncates floating-point value(s) to integer value(s) | 1 |

转 http://www.cppblog.com/lai3d/archive/2008/10/23/64889.html