shader实现类
const char* vs = { "attribute vec3 inVertex;" "attribute vec3 inNormal;" "attribute vec2 inTexCoord;" "uniform mat4 MVPMatrix;" "uniform mat4 ModelViewMatrix;" "uniform vec3 LightDirection;" "uniform float FogDensity;"//雾浓度 "uniform float FogEnd;"//雾结束的位置 "varying vec2 TexCoord;" "varying vec3 DiffuseLight;" "varying vec3 FogIntensity;"//随距离变换的雾的强度 "void main()" "{" //这里需要将顶点转化到摄像机空间，目的是用来计算摄像机与顶点之间的距离 "vec3 viewPos=vec3(ModelViewMatrix*vec4(inVertex,1));" "float eyeDist=length(viewPos);" //length(x): 向量长度 "gl_Position=MVPMatrix*vec4(inVertex,1);" "TexCoord=inTexCoord;" "float DiffuseIntensity=dot(inNormal,normalize(LightDirection));"//求两向量的点积 "DiffuseLight=vec3(max(DiffuseIntensity,0.0)*0.5+0.5);" "float fogIntensity=1.0;" "fogIntensity=(FogEnd-eyeDist)*FogDensity;" //clamp(x, min, max) 把输入值限制在[min, max]范围内 "fogIntensity=clamp(fogIntensity,0.0,1.0);" "FogIntensity=vec3(fogIntensity,fogIntensity,fogIntensity);" "}" }; const char* ps = { "precision lowp float;" "uniform sampler2D sTexture;" "uniform vec3 FogColor;" "varying vec2 TexCoord;" "varying vec3 DiffuseLight;" "varying vec3 FogIntensity;" "void main()" "{" "vec3 texColor=texture2D(sTexture,TexCoord).rgb;" "vec3 color=texColor*DiffuseLight;" //mix(x, y, a): x, y的线性混叠， x(1-a) + y*a; "color=mix(FogColor,color,FogIntensity);" "gl_FragColor=vec4(color,1.0);" "}" }; 渲染函数 virtual void onRender(Program_Fog& shader,CELL3RDCamera& camera) { static float angle = 0; matrix4 matRot(1); matRot.rotateY(angle); matrix4 matTrans; matTrans.translate(0,5,0); matrix4 matScale(1); matScale.scale(0.3f,0.3f,0.3f); //总的模型变换矩阵 matrix4 matModel = matTrans*matRot*matScale; angle += 1.0f; matrix4 MVP = camera._matProj*camera._matView*matModel; matrix4 mv = camera._matView*matModel; matrix4 mvI = mv.inverse(); float4 vEyePosModel; vEyePosModel = mvI*float4(0,0,0,1); const float fFogStart = 0.0f;//雾开始的地方 const float fFogEnd = 200;//雾结束的地方 const float fFogDensity = 0.0017f;//雾浓度 const float afFogColor[3] = { 0.6f, 0.8f, 1.0f };//雾的颜色 _device.setUniform1f(shader.FogEnd,fFogEnd); _device.setUniform1f(shader.FogDensity,fFogDensity); _device.setUniform3fv(shader.FogColor,1,afFogColor); //设置观察点坐标 _device.setUniform3fv(shader.EyePositon,1,(float*)&camera._eye); _device.setUniformMatrix4fv(shader.MVPMatrix,1,false,MVP.data()); _device.setUniformMatrix4fv(shader.ModelViewMatrix,1,false,mv.data()); VertexBumpMap* vert = &_arVertexs.front(); _device.attributePointer(shader.inVertex,3,GL_FLOAT,GL_FALSE,sizeof(VertexBumpMap),vert); _device.attributePointer(shader.inNormal, 3, GL_FLOAT, GL_FALSE, sizeof(VertexBumpMap), &vert[0]._normal); _device.attributePointer(shader.inTexCoord, 2, GL_FLOAT, GL_FALSE, sizeof(VertexBumpMap), &vert[0]._uv); _device.drawElements(GL_TRIANGLES,_arFaces.size()*3,GL_UNSIGNED_SHORT,&_arFaces.front()); }