learn-opengl/13-multiple-lights/shaders/12-frag.glsl
2026-08-23 13:25:45 -04:00

67 lines
1.6 KiB
GLSL

#version 330 core
struct Material {
sampler2D diffuse;
sampler2D specular;
float shininess;
};
struct Light {
vec3 direction;
vec3 position;
vec3 diffuse;
vec3 specular;
vec3 ambient;
float constant;
float linear;
float quadratic;
float cutOff;
float outerCutOff;
};
out vec4 FragColor;
in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoords;
uniform vec3 viewPos;
uniform Light light;
uniform Material material;
void main()
{
vec3 lightDir = normalize(light.position - FragPos);
vec3 mat_tex = vec3(texture(material.diffuse, TexCoords));
vec3 spec_tex = vec3(texture(material.specular, TexCoords));
vec3 ambient = light.ambient * mat_tex;
vec3 norm = normalize(Normal);
float diff = max(dot(norm, lightDir), 0.0);
vec3 diffuse = light.diffuse * diff * mat_tex;
vec3 viewDir = normalize(viewPos - FragPos);
vec3 reflectDir = reflect(-lightDir, norm);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
vec3 specular = light.specular * spec * spec_tex;
// splotlight
float theta = dot(lightDir, normalize(-light.direction));
float epsilon = light.cutOff - light.outerCutOff;
float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
diffuse *= intensity;
specular *= intensity;
// determine attenuation based on light distance
float distance = length(light.position - FragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
ambient *= attenuation;
diffuse *= attenuation;
specular *= attenuation;
vec3 result = ambient + diffuse + specular;
FragColor = vec4(result, 1.0);
}