[SOLVED] CS代考计算机代写 // Phong fragment shader WITH TEXTURES

// Phong fragment shader WITH TEXTURES
//
// Phong shading with diffuse and specular components

#version 300 es

uniform sampler2D texUnitID;

uniform mediump vec3 lightDir;

uniform mediump vec2 texDim;

uniform mediump vec3 kd;
uniform mediump vec3 ks;
uniform mediump vec3 Ia;
uniform mediump vec3 Ei;
uniform mediump float shininess;

uniform int mode;

smooth in mediump vec3 colour;
smooth in mediump vec3 normal;
smooth in mediump vec2 texCoords;
smooth in mediump float depth;

out mediump vec4 outputColour;

// Get the mipmap level
//
// From https://stackoverflow.com/questions/24388346/how-to-access-automatic-mipmap-level-in-glsl-fragment-shader-texture

mediump float getMipMapLevel( sampler2D texUnitID, vec2 texCoords )

{
// For GLSL >= 4.0
//
// return textureQueryLod(myTexture, textureCoord).x

// For GLSL < 4.0mediump vec2dx_vtc= dFdx( texCoords );mediump vec2dy_vtc= dFdy( texCoords );mediump float delta_max_sqr = max( dot(dx_vtc, dx_vtc), dot(dy_vtc, dy_vtc) );mediump float mml = 0.5 * log2(delta_max_sqr);return max( 0.0, mml );}const mediump vec3 colours[6] =vec3[6]( vec3( 129.0/255.0,15.0/255.0, 124.0/255.0 ), vec3( 136.0/255.0,86.0/255.0, 167.0/255.0 ), vec3( 140.0/255.0, 150.0/255.0, 198.0/255.0 ), vec3( 158.0/255.0, 188.0/255.0, 218.0/255.0 ), vec3( 191.0/255.0, 211.0/255.0, 230.0/255.0 ), vec3( 237.0/255.0, 248.0/255.0, 251.0/255.0 ) );void main(){// Look up texture value of this fragmentmediump vec3 texColour = texture( texUnitID, texCoords ).rgb;if (mode == 0)// 1. Show texture without any shadingoutputColour = vec4( texColour, 1.0f ); // show textureelse if (mode == 1)// 2. show (x,y) texture coordinate as (red,green)outputColour = vec4( fract(texCoords.x), fract(texCoords.y), 0.0f, 1.0f );else if (mode == 6) {// show mipmap levelsint level = int( floor( getMipMapLevel( texUnitID, texCoords*texDim ) ) );if (level > 5)
level = 5;

outputColour = vec4( colours[level], 1.0 );

} else {

// 3. Standard Phong diffuse+specular calculation

mediump vec3 Iin = vec3( 1.0, 1.0, 1.0 ); // incoming light

mediump vec3 N = normalize( normal );

mediump float NdotL = dot( N, lightDir );

// Compute the outgoing colour

mediump vec3 Iout = Ia;

if (NdotL > 0.0) {

if (mode == 2)
// no texturing
Iout += NdotL * (kd * Iin);

if (mode == 3)
// 4. “replace” background with texture
Iout += NdotL * (texColour * Iin);

else if (mode == 4)
// 5. “decal” over background (= (0,4,0) pixels) with texture
//(try with Kd = 1,1,1 for tree1 in cube.mtl)

if (texColour == vec3(0,4.0/255.0,0))
Iout += NdotL * (kd * Iin);
else
Iout += NdotL * (texColour * Iin);

else if (mode == 5)
// 6. “modulate” background with texture
Iout += NdotL * (kd * (texColour * Iin));

// specular component

mediump vec3 R = (2.0 * NdotL) * N – lightDir;
mediump vec3 V = vec3(0.0,0.0,1.0);// direction toward eye in the VCS

mediump float RdotV = dot( R, V );

if (RdotV > 0.0)
Iout += pow( RdotV, shininess ) * (ks * Iin);
}

outputColour = vec4( Iout, 1.0f );
}
}