Merge branch 'master' of github.com:omnisci3nce/celeritas-core

1 files changed, 95 insertions, 0 deletions

diff --git a/assets/shaders/blinn_phong.frag b/assets/shaders/blinn_phong.frag
new file mode 100644
index 0000000..095b19a
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+++ b/assets/shaders/blinn_phong.frag
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+#version 410 core
+out vec4 FragColor;
+
+// A Blinn-Phong material with textures for diffuse and specular
+// lighting maps and a numeric shininess factor.
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;    
+    float shininess;
+};
+
+struct DirLight {
+    vec3 direction;
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+struct PointLight {
+    vec3 position;
+    // fall off properties
+    float constant;
+    float linear;
+    float quadratic;
+
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
+
+in VS_OUT {
+  vec3 FragPos;
+  vec3 Normal;
+  vec2 TexCoords;
+  vec4 FragPosLightSpace;
+} fs_in;
+
+// --- Uniforms
+#define NUM_POINT_LIGHTS 4
+uniform vec3 viewPos;
+uniform Material material;
+uniform DirLight dirLight;
+uniform PointLight pointLights[NUM_POINT_LIGHTS];
+
+// --- Function prototypes
+vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir);
+vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
+
+void main() {
+  vec3 norm = normalize(fs_in.Normal);
+  vec3 viewDir = normalize(viewPos - fs_in.FragPos);
+
+  vec3 result = CalcDirLight(dirLight, norm, viewDir);
+  for (int i = 0; i < 4; i++) {
+    result += CalcPointLight(pointLights[i], norm, fs_in.FragPos, viewDir);
+  }
+
+  FragColor = vec4(result, 1.0);
+}
+
+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 result
+    vec3 ambient = light.ambient * vec3(texture(material.diffuse, fs_in.TexCoords));
+    vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, fs_in.TexCoords));
+    vec3 specular = light.specular * spec * vec3(texture(material.specular, fs_in.TexCoords));
+    return (ambient + diffuse + specular);
+}
+
+vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
+{
+    vec3 lightDir = normalize(light.position - fragPos);
+    // diffuse
+    float diff = max(dot(normal, lightDir), 0.0);
+    // specular
+    vec3 reflectDir = reflect(-lightDir, normal);
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    // attentuation
+    float distance = length(light.position - fragPos);
+    float attentuation = 1.0 / (light.constant + light.linear * distance * light.quadratic * (distance * distance));
+    // result
+    vec3 ambient = light.ambient * vec3(texture(material.diffuse, fs_in.TexCoords));
+    vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, fs_in.TexCoords));
+    vec3 specular = light.specular * spec * vec3(texture(material.specular, fs_in.TexCoords));
+    ambient *= attentuation;
+    diffuse *= attentuation;
+    specular *= attentuation;
+    return (ambient + diffuse + specular);
+}
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