added skybox asset

assets/shaders/deferred.frag

@@ -1,24 +1,83 @@
 #version 450
 
+#include "shaders://_builtins/constants.glsl"
+#include "shaders://_builtins/PBR.glsl"
+
+struct Light {
+  mat4 tranform;
+  vec4 color;
+  float intensity;
+};
+
+const int MAX_LIGHT_COUNT = 128;
+
+layout( push_constant ) uniform constants
+{
+  uint lightCount;
+} PushConstants;
+
 layout(set = 0, binding = 0) uniform sampler2D positionTexture;
-
 layout(set = 0, binding = 1) uniform sampler2D normalTexture;
-
 layout(set = 0, binding = 2) uniform sampler2D albedoTexture;
-
 layout(set = 0, binding = 3) uniform sampler2D specularTexture;
 
+layout(set = 1, binding = 1) uniform LightBuffer {
+  layout(align = 16) Light lights[MAX_LIGHT_COUNT];
+} LightsBuffer;
+
 layout (location = 0) in vec2 inUV;
+layout(location = 1) in vec3 cameraPos;
 
 layout(location = 0) out vec4 outColor;
 
 void main()
 {
-  vec3 fragPos = texture(positionTexture, inUV).rgb;
+  vec3 position = texture(positionTexture, inUV).rgb;
   vec3 normal = texture(normalTexture, inUV).rgb;
-  vec4 albedo = texture(albedoTexture, inUV);
+  vec3 albedo = texture(albedoTexture, inUV).rgb;
 
-  // outColor = vec4(fragPos, 1.0);
-  // outColor = vec4(normal, 1.0);
-  outColor = albedo;
+  vec3 spec = texture(specularTexture, inUV).rgb;
+  float metallicFactor = spec.b;
+  float roughnessFactor = spec.g;
+  float ao = spec.r;
+
+  vec3 V = normalize(cameraPos - position);
+
+  vec3 Lo = vec3(0);
+  for(int i = 0; i < PushConstants.lightCount; ++i)
+  {
+    Light l = LightsBuffer.lights[i];
+
+    vec3 L = normalize(l.tranform[3].xyz - position);
+    vec3 H = normalize(V + L);
+    float distance    = length(l.tranform[3].xyz - position);
+    float attenuation = 1.0 / (distance * distance);
+    vec3 radiance     = l.color.xyz * attenuation * l.intensity;
+
+    vec3 F0 = vec3(0.04);
+    F0      = mix(F0, albedo, metallicFactor);
+
+    vec3 F  = fresnelSchlick(max(dot(H, V), 0.0), F0);
+    float NDF = DistributionGGX(normal, H, roughnessFactor);
+    float G   = GeometrySmith(normal, V, L, roughnessFactor);
+
+    vec3 numerator    = NDF * G * F;
+    float denominator = 4.0 * max(dot(normal, V), 0.0) * max(dot(normal, L), 0.0);
+    vec3 specular     = numerator / max(denominator, 0.001);
+
+    vec3 kS = F;
+    vec3 kD = vec3(1.0) - kS;
+    kD *= 1.0 - metallicFactor;
+
+    float NdotL = max(dot(normal, L), 0.0);
+    Lo += (kD * albedo / PI + specular) * radiance * NdotL;
+  }
+
+  vec3 ambient = vec3(0.2) * albedo * ao;
+
+  vec3 color   = ambient + Lo;
+  // color += vec3();
+  color = color / (color + vec3(1.0));
+
+  outColor = vec4(color, 1.0);
 }