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XCEngine/MVS/OpenGL/Shaders/fragmentshader.glsl

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3.6 KiB
GLSL

#version 330 core
out vec4 FragColor;
struct Material {
sampler2D texture_diffuse1;
sampler2D texture_diffuse2;
sampler2D texture_diffuse3;
sampler2D texture_specular1;
sampler2D texture_specular2;
float shininess;
};
struct DirLight {
vec3 direction;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
struct PointLight {
vec3 position;
float constant;
float linear;
float quadratic;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
#define NR_POINT_LIGHTS 10
in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoords;
uniform int PointLightNum;
uniform vec3 viewPos;
uniform DirLight dirLight;
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform Material material;
// function prototypes
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir);
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
void main()
{
// properties
vec3 norm = normalize(Normal);
vec3 viewDir = normalize(viewPos - FragPos);
// == =====================================================
// Our lighting is set up in 3 phases: directional, point lights and an optional flashlight
// For each phase, a calculate function is defined that calculates the corresponding color
// per lamp. In the main() function we take all the calculated colors and sum them up for
// this fragment's final color.
// == =====================================================
// phase 1: directional lighting
vec3 result = CalcDirLight(dirLight, norm, viewDir);
// phase 2: point lights
for(int i = 0; i < PointLightNum; i++)
{
result += CalcPointLight(pointLights[i], norm, FragPos, viewDir);
}
// phase 3: spot light
FragColor = vec4(result, 1.0);
}
// calculates the color when using a directional light.
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
{
vec3 lightDir = normalize(-light.direction);
// diffuse shading
float diff = max(dot(normal, lightDir), 0.0);
// specular shading
vec3 reflectDir = reflect(-lightDir, normal);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
// combine results
vec3 ambient = light.ambient * vec3(texture(material.texture_diffuse1, TexCoords));
vec3 diffuse = light.diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords));
vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords));
return (ambient + diffuse + specular);
}
// calculates the color when using a point light.
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
{
vec3 lightDir = normalize(light.position - fragPos);
// diffuse shading
float diff = max(dot(normal, lightDir), 0.0);
// specular shading
vec3 reflectDir = reflect(-lightDir, normal);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
// attenuation
float distance = length(light.position - fragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
attenuation = min(attenuation, 1.0f);
// combine results
vec3 ambient = light.ambient * vec3(texture(material.texture_diffuse1, TexCoords));
vec3 diffuse = light.diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords));
vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords));
ambient *= attenuation;
diffuse *= attenuation;
specular *= attenuation;
return (ambient + diffuse + specular);
}