36 lines
1.4 KiB
C++
36 lines
1.4 KiB
C++
#include "light/light.h"
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#include "scene/scene.h"
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#include "shader/phongshader.h"
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PhongShader::PhongShader(Color const &diffuseColor, float diffuseCoefficient, Color const &specularColor,
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float specularCoefficient, float shininessExponent)
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: diffuseColor(diffuseColor), diffuseCoefficient(diffuseCoefficient), specularColor(specularColor),
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specularCoefficient(specularCoefficient), shininessExponent(shininessExponent) {}
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Color PhongShader::shade(Scene const &scene, Ray const &ray) const {
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Color fragmentColor;
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// Calculate the reflection vector
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Vector3d const reflection = ray.direction - 2 * dotProduct(ray.normal, ray.direction) * ray.normal;
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// Accumulate the light over all light sources
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for (const auto &light : scene.lights()) {
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Light::Illumination illum;
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illum = light->illuminate(scene, ray);
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// Diffuse term
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Color const diffuse =
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this->diffuseCoefficient * this->diffuseColor * std::max(dotProduct(-illum.direction, ray.normal), 0.0f);
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fragmentColor += diffuse * illum.color;
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// Specular term
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float const cosine = dotProduct(-illum.direction, reflection);
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if (cosine > 0) {
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Color const specular = this->specularCoefficient * this->specularColor // highlight
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* powf(cosine, this->shininessExponent); // shininess factor
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fragmentColor += specular * illum.color;
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}
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}
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return fragmentColor;
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}
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