1. UINT Createshader (enum type): Creates an empty shader object;
Type:vertex_shader,
2, void Shadersource (UINT shader, Sizeicount, const **string, const int *length): Load shader source into shader object; possibly multiple strings
3, void Compileshader (UINT shader): Compile shader object;
Shader object has a status indicating the result of the compilation
4, void Deleteshader (UINT shader): Delete shader object;
5, void Shaderbinary (Sizei count, const UINT *shaders,
Enum Binaryformat, const void *binary, Sizei length): Loads pre-compiled shader binary strings;
6, uint Createprogram (void): Create an empty program object, Programe object organization multiple shader object, become executable;
7. Void Attachshader (UINT program, UINT shader): Associative shader object and program object;
8, void Detachshader (UINT program, UINT shader): disassociate;
9, void Linkprogram (UINT program): The program object is ready to execute, its associated shader object must compile correctly and meet the constraints;
10, void Useprogram (UINT program): Execute program object;
11. Void Programparameteri (UINT program, enum PName,
int value): Sets the parameter of program object;
12, void Deleteprogram (UINT program): Delete program object;
13, the qualifier of shader variable:
Default: No modifier, normal variable read and write, and no connection to the outside world;
Const: Constant const VEC3 Zaxis = VEC3 (0.0, 0.0, 1.0);
attribute: Declare the variable passed to vertex shader; Read only; cannot be an array or struct;attribute VEC4 position;
Uniform: Indicates the same value in the whole entity processing, read-only, uniform vec4 lightpos;
Varying: By the difference, reading and writing, varying vec3 normal;
In, out, inout;
14, the accuracy of shader variable:
HIGHP, Mediump, LOWP
15. Shader built-in variables:
Gl_position: Used for vertex shader, writing vertex position, being used in fixed operation functions such as collection and cropping of elements;
Its internal statement is: HIGHP VEC4 gl_position;
Gl_pointsize: For vertex shader, the point size after the rasterization, the number of pixels;
Its internal statement is: Mediump float gl_position;
Gl_fragcolor: Used for fragment shader, write fragment color, and be used by subsequent fixed pipelines;
Mediump VEC4 Gl_fragcolor;
Gl_fragdata: For fragment shader, is the number of groups, write Gl_fragdata[n] for the data n; be used by subsequent fixed pipelines;
Mediump VEC4 Gl_fragdata[gl_maxdrawbuffers];
Gl_fragcolor and Gl_fragdata are mutually exclusive and do not write at the same time;
Gl_fragcoord: For fragment shader, read-only, fragment relative to the coordinate position of the window x,y,z,1/w; This is generated after the fixed line element difference, Z is the depth value; Mediump VEC4 Gl_fragcoord;
Gl_frontfacing: Used to judge whether fragment belongs to front-facing primitive;
BOOL gl_frontfacing;
Gl_pointcoord: for point Primitive only; Mediump VEC2 Gl_pointcoord;
16. Shader built-in constants:
const Mediump INT gl_maxvertexattribs = 8;
const Mediump INT gl_maxvertexuniformvectors = 128;
const Mediump INT gl_maxvaryingvectors = 8;
const Mediump int gl_maxvertextextureimageunits = 0;
const Mediump INT gl_maxcombinedtextureimageunits = 8;
const Mediump INT gl_maxtextureimageunits = 8;
const Mediump INT gl_maxfragmentunitformvectors = 16;
const Mediump int gl_maxdrawbuffers = 1;
17. Shader built-in function:
The general default is in radians;
Radians (degree): Angle variable radian;
Degrees (radian): radian variable angle;
Sin (angle), cos (angle), tan (angle)
ASIN (x): Arc sine, return radians [-PI/2, PI/2];
ACOs (x): Arc cosine, return radians [0, PI];
Atan (y, x): Arc tangent, return radians [-pi, PI];
Atan (y/x): Arc tangent, return radians [-PI/2, PI/2];
Pow (x, y): X's y-square;
EXP (x): Exponent, log (x):
EXP2 (x): 2 x-Square, log2 (x):
sqrt (x): the radical of X; inversesqrt (x): The reciprocal of the X-root
ABS (x): Absolute value
Sign (x): symbol, 1, 0 or-1
A sign (x) or symbol (x) is called a symbolic function, and in mathematical and computer operations, it is the function of taking a number of symbols (positive or negative):
When x>0,sign (x) = 1;
When x=0,sign (x) = 0;
When x<0, sign (x) =-1;} Floor (x): Bottom Rounding
Ceil (x): Top rounding
Fract (x): Take a decimal part
MoD (x, y): modulo, x-y*floor (×/x)
Min (x, y): Take minimum value
Max (x, y): Take the maximum value
Clamp (x, Min, max): Min (max (x, Min), max);
Mix (x, Y, a): X, y linear aliasing, X (1-a) + y*a;
Step (Edge, X): 0.0 if x<edge, otherwise 1.0
Smoothstep (EDGE0, Edge1, x): used when Threshod smooth transition. Edge0<x<edge1 smoothing Difference, 0.0 at X<=EDGE0, 1.0 at X>=edge1
Length (x): vector lengths
Distance (P0, p1): Two point distance, length (P0-P1);
Dot (x, y): dot product, each component is multiplied and then added
Cross (x, y): Differential product, x[1]*y[2]-y[1]*x[2], x[2]*y[0]-y[2]*x[0], x[0]*y[1]-y[0]*x[1]
Normalize (x): Normalized, Length (x) = 1;
Faceforward (n, I, nref): such as dot (Nref, i) < 0 N, otherwise-n
Reflect (I, N): The reflection direction of I, I-2*dot (n, I) *n, n must be normalized first
Refract (i, N, ETA): Refraction, k=1.0-eta*eta* (1.0-dot (n, i) * DOT (n, i)); If k<0.0 is 0.0, otherwise eta*i-(Eta*dot (N, I) +sqrt (k)) *n
Matrixcompmult (mATX, Maty): Multiply the matrix by multiplying each component by itself, i.e. R
[j] = x[J]*y[j];
Linear multiplication of matrices, directly using *
LessThan (VECX, vecy): Vector per component comparison x < Y
Lessthanequal (VECX, vecy): Vector per component comparison X<=y
GreaterThan (VECX, vecy): Vector per component comparison X>y
Greaterthanequal (VECX, vecy): Vector per component comparison X>=y
Equal (VECX, vecy): Vector per component comparison X==y
NotEqual (VECX, vexy): Vector per component comparison X!=y
Any (BVECX): True if one component is true
All (BVECX): True if all components are true
Not (BVECX): All components take the inverse
Texture2d (sampler2d, coord): Texture Lookup
Texture2d (sampler2d, coord, bias): LOD bias, mip-mapped texture
Texture2dproj (sampler2d, coord):
Texture2dproj (sampler2d, coord, bias):
Texture2dlod (sampler2d, Coord, LOD):
Texture2dprojlod (sampler2d, Coord, LOD):
Texturecube (Samplercube, coord):
Texturecube (Samplercube, coord, bias):
Texturecubelod (Samplercube, Coord, LOD):
Shader built-in variables and functions
