phong_fs.c

static const char* phong_fs = "#version 330 core\n"
"\n"
"//\n"
"// Phong uses two textures, diffuse and specular, and an ambient\n"
"// color to light the object.\n"
"//\n"
"\n"
"// Structs and uniforms\n"
"\n"
"struct Material\n"
"{\n"
"  // These values as specific to phong\n"
"  sampler2D texture_diffuse1;\n"
"  sampler2D texture_specular1;\n"
"  float     shininess;\n"
"};\n"
"uniform Material material;\n"
"\n"
"struct DirLight\n"
"{\n"
"  vec3  direction;\n"
"  vec3  ambient;\n"
"  vec3  diffuse;\n"
"  vec3  specular;\n"
"  float strength;\n"
"};\n"
"uniform DirLight dir_light;\n"
"uniform bool     use_dir_light = false; // Set this to true to enable directional light\n"
"\n"
"struct PointLight\n"
"{\n"
"  vec3  position;\n"
"  float strength;\n"
"\n"
"  vec3 ambient;\n"
"  vec3 diffuse;\n"
"  vec3 specular;\n"
"\n"
"  // Light attenuation\n"
"  float constant;\n"
"  float linear;\n"
"  float quadratic;\n"
"};\n"
"#define NR_POINT_LIGHTS 4\n"
"uniform PointLight point_lights[NR_POINT_LIGHTS];\n"
"uniform int n_point_lights = 0; // Set this to the number of point lights you have\n"
"\n"
"uniform vec3 view_pos;\n"
"uniform float transparency = 1.0;\n"
"\n"
"// inputs\n"
"in vec3 Normal;\n"
"in vec3 FragPos;\n"
"in vec2 TexCoords;\n"
"\n"
"// Outputs\n"
"out vec4 FragColor; \n"
"\n"
"// Function prototypes\n"
"vec3 calc_dir_light(DirLight light, vec3 normal, vec3 viewDir);\n"
"vec3 calc_point_light(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);\n"
"\n"
"void main()\n"
"{\n"
"  vec4 textColor = texture(material.texture_diffuse1, TexCoords);\n"
"  if (textColor.a < 0.1) discard;\n"
"\n"
"  vec3 norm = normalize(Normal);\n"
"  vec3 viewDir = normalize(view_pos - FragPos);\n"
"\n"
"  vec3 result = vec3(0.0);\n"
"\n"
"  // Directional light\n"
"  if (use_dir_light)\n"
"  {\n"
"    result = calc_dir_light(dir_light, norm, viewDir);\n"
"  }\n"
"  else\n"
"  {\n"
"    // If we don't have a directional light, just use the texture\n"
"    result = vec3(textColor);\n"
"  }\n"
"\n"
"  // Point lights\n"
"  if (n_point_lights > 0)\n"
"  {\n"
"    for (int i = 0; i < NR_POINT_LIGHTS; i++)\n"
"    {\n"
"      if (i >= n_point_lights) break;\n"
"      result += calc_point_light(point_lights[i], norm, FragPos, viewDir);\n"
"    }\n"
"  }\n"
"\n"
"  // Output result\n"
"  FragColor = vec4(result, transparency);\n"
"}\n"
"\n"
"vec3 calc_dir_light(DirLight light, vec3 normal, vec3 viewDir) \n"
"{\n"
"  vec3 lightDir = normalize(-light.direction);\n"
"\n"
"  // diffuse shading\n"
"  float diff = max(dot(normal, lightDir), 0.0);\n"
"\n"
"  // specular shading\n"
"  vec3 reflectDir = reflect(-lightDir, normal);\n"
"  float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess );\n"
"\n"
"  // combine results\n"
"  vec3 ambient  = light.ambient  * vec3(texture(material.texture_diffuse1, TexCoords));\n"
"  vec3 diffuse  = light.diffuse  * diff * vec3(texture(material.texture_diffuse1, TexCoords));\n"
"  vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords));\n"
"  return (ambient + diffuse + specular) * light.strength;\n"
"}\n"
"\n"
"vec3 calc_point_light(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)\n"
"{\n"
"  vec3 lightDir = normalize(light.position - fragPos);\n"
"\n"
"  // diffuse shading\n"
"  float diff = max(dot(normal, lightDir), 0.0);\n"
"\n"
"  // specular shading\n"
"  vec3 reflectDir = reflect(-lightDir, normal);\n"
"  float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);\n"
"\n"
"  // attenuation\n"
"  float distance    = length(light.position - fragPos);\n"
"  float attenuation = 1.0 / (light.constant + light.linear * distance + \n"
"                             light.quadratic * (distance * distance));\n"
"\n"
"  // combine results\n"
"  vec3 ambient  = light.ambient  * vec3(texture(material.texture_diffuse1, TexCoords));\n"
"  vec3 diffuse  = light.diffuse  * diff * vec3(texture(material.texture_diffuse1, TexCoords));\n"
"  vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords));\n"
"  ambient  *= attenuation;\n"
"  diffuse  *= attenuation;\n"
"  specular *= attenuation;\n"
"  return (ambient + diffuse + specular) * light.strength;\n"
"}\n"
;