图形着色器——理论与实践(第2版) 

这个书在一些翻译上比较坑，而且案例都是都不完整，更重要的是中文翻译版本竟然没有书的网站也就是说没有案例代码。

所以在此我说一下网址：http://cgeducation.org/ShadersBookSecond/Source/

Demo.glib

Ortho -1. 1. -1. 1 .. 1 1000.

Vertex demo.vert

Fragment demo.frag

Program Dome

Color 1. .5 0.

QuadXY -2. 5. 200 200

 

demo.vert

in vec4 aVertex;

in vec4 aColor;

varying float vLightIntensity;

varying vec3 vColor;

vec3 LIGHTPOS =vec3(0.,2.,0.);

vec3 ECpos;

void main(void)

{

vec4 thisPos=aVertex;

vColor=aColor.rgb;

float thisX=thisPos.x;

float thisY=thisPos.y;

vec2 thisXY=thisPos.xy;

thisPos.z=0.3*sin(dot(thisXY,thisXY));

//计算法线，求微分

vec3 xtangent=vec3(1.,0.,0.);

xtangent.z=2.*0.3*thisX*cos(dot(thisXY,thisXY));

vec3 ytangent=vec3(0.,1.,0.);

ytangent.z=2.*0.3*thisY*cos(dot(thisXY,thisXY));

vec3 thisNormal=normalize(cross(xtangent,ytangent));

vec3 ECpos=vec3(gl_ModelViewMatrix*thisPos);

vLightIntensity=dot(normalize(LIGHTPOS-ECpos),thisNormal);

vLightIntensity=0.3+abs(vLightIntensity); //环境光

vLightIntensity=clamp(vLightIntensity,0.0,1.0);

gl_Position=gl_ModelViewProjectionMatrix*thisPos;

}

 

demo.frag

 

in vec4 vColor;

in float vLightIntensity;

void

main(void)

{

gl_FragColor = vColor*vLightIntensity;

}