learn-opengl/19-blending-facecull/shaders/17-frag.glsl
2026-08-30 13:51:01 -04:00

162 lines
4.2 KiB
GLSL

#version 330 core
struct Material {
sampler2D diffuse;
sampler2D specular;
float shininess;
};
out vec4 FragColor;
in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoords;
uniform vec3 viewPos;
uniform Material material;
struct DirLight {
vec3 direction;
vec3 ambient;
vec3 diffuse;
vec3 specular;
};
struct PointLight {
vec3 position;
vec3 ambient;
vec3 diffuse;
vec3 specular;
float constant;
float linear;
float quadratic;
};
struct SpotLight {
vec3 direction;
vec3 position;
vec3 diffuse;
vec3 specular;
vec3 ambient;
float constant;
float linear;
float quadratic;
float cut_off;
float outer_cut_off;
};
#define MAX_LIGHTS 4
uniform int pointLightCount = 0;
uniform PointLight pointLights[MAX_LIGHTS];
uniform int dirLightCount = 0;
uniform DirLight dirLights[MAX_LIGHTS];
uniform int spotLightCount = 0;
uniform SpotLight spotLights[MAX_LIGHTS];
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
{
vec3 mat_tex = vec3(texture(material.diffuse, TexCoords));
vec3 spec_tex = vec3(texture(material.specular, TexCoords));
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);
vec3 ambient = light.ambient * mat_tex;
vec3 diffuse = light.diffuse * diff * mat_tex;
vec3 specular = light.specular * spec * spec_tex;
return ambient + diffuse + specular;
}
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
{
vec3 mat_tex = vec3(texture(material.diffuse, TexCoords));
vec3 spec_tex = vec3(texture(material.specular, TexCoords));
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));
vec3 ambient = light.ambient * mat_tex;
vec3 diffuse = light.diffuse * diff * mat_tex;
vec3 specular = light.specular * spec * spec_tex;
ambient *= attenuation;
diffuse *= attenuation;
specular *= attenuation;
return ambient + diffuse + specular;
}
vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
{
vec3 mat_tex = vec3(texture(material.diffuse, TexCoords));
vec3 spec_tex = vec3(texture(material.specular, TexCoords));
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));
vec3 ambient = light.ambient * mat_tex;
vec3 diffuse = light.diffuse * diff * mat_tex;
vec3 specular = light.specular * spec * spec_tex;
float theta = dot(lightDir, normalize(-light.direction));
float epsilon = light.cut_off - light.outer_cut_off;
float intensity = clamp((theta - light.outer_cut_off) / epsilon, 0.0, 1.0);
diffuse *= intensity;
specular *= intensity;
ambient *= attenuation;
diffuse *= attenuation;
specular *= attenuation;
return ambient + diffuse + specular;
}
void main()
{
vec3 norm = normalize(Normal);
vec3 viewDir = normalize(viewPos - FragPos);
// kick it off with the first dirlight
vec3 result = CalcDirLight(dirLights[0], norm, viewDir);
// then augment with more (off by one)
for(int i = 1; i < dirLightCount; i++) {
result += CalcDirLight(dirLights[i], norm, viewDir);
}
for(int i = 0; i < pointLightCount; i++) {
result += CalcPointLight(pointLights[i], norm, FragPos, viewDir);
}
for(int i = 0; i < spotLightCount; i++) {
result += CalcSpotLight(spotLights[i], norm, FragPos, viewDir);
}
FragColor = vec4(result, 1.0);
}