opengl-stuff/shaders/lighting_fragment.glsl
2023-08-21 17:43:31 +03:00

128 lines
3.8 KiB
GLSL

#version 330 core
out vec4 FragColor;
in vec3 Normal;
in vec3 FragPos;
in vec2 TexCoords;
struct Material {
sampler2D diffuse;
sampler2D specular;
float shininess;
};
struct PointLight {
vec3 position;
vec3 ambient;
vec3 diffuse;
vec3 specular;
float constant;
float linear;
float quadratic;
};
struct DirectionalLight {
vec3 direction;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
struct SpotLight {
vec3 position;
vec3 direction;
float cutOff;
float outerCutOff;
vec3 ambient;
vec3 diffuse;
vec3 specular;
float constant;
float linear;
float quadratic;
};
#define POINT_LIGHTS_COUNT 4
uniform Material material;
uniform vec3 viewPos;
uniform SpotLight spotLight;
uniform DirectionalLight directionalLight;
uniform PointLight pointLights[POINT_LIGHTS_COUNT];
vec3 ComputeDirectionalLight(DirectionalLight light, vec3 norm, vec3 viewDir)
{
vec3 lightDir = normalize(-light.direction);
vec3 reflectDir = reflect(-lightDir, norm);
float diff = max(dot(norm, lightDir), 0.0);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
return (ambient + diffuse + specular);
}
vec3 ComputePointLight(PointLight light, vec3 norm, vec3 viewDir, vec3 fragPos)
{
float distance = length(light.position - fragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
vec3 lightDir = normalize(light.position - fragPos);
vec3 reflectDir = reflect(-lightDir, norm);
float diff = max(dot(norm, lightDir), 0.0);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
return (ambient * attenuation + diffuse * attenuation + specular * attenuation);
}
vec3 ComputeSpotLight(SpotLight light, vec3 norm, vec3 viewDir, vec3 fragPos) {
vec3 lightDir = normalize(light.position - fragPos);
vec3 reflectDir = reflect(-lightDir, norm);
float theta = dot(lightDir, normalize(-light.direction));
float epsilon = light.cutOff - light.outerCutOff;
float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
float distance = length(light.position - fragPos);
float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
float diff = max(dot(norm, lightDir), 0.0);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
// we leave ambient alone so there's always a little light
return ((ambient * attenuation) + (diffuse * intensity * attenuation) + (specular * intensity * attenuation));
}
void main()
{
vec3 norm = normalize(Normal);
vec3 viewDir = normalize(viewPos - FragPos);
vec3 result = vec3(0.0);
result += ComputeDirectionalLight(directionalLight, norm, viewDir);
for (int i = 0; i < POINT_LIGHTS_COUNT; i++) {
result += ComputePointLight(pointLights[i], norm, viewDir, FragPos);
}
result += ComputeSpotLight(spotLight, norm, viewDir, FragPos);
FragColor = vec4(result, 1.0);
}