added shadow rendering

assets/shaders/deferred.frag

@@ -4,13 +4,18 @@
 #include "shaders://_builtins/PBR.glsl"
 
 struct Light {
-  mat4 tranform;
+  mat4 transform;
   vec4 color;
   float intensity;
 };
 
 const int MAX_LIGHT_COUNT = 128;
 
+#define SHADOW_FACTOR 0.25
+layout(set = 1, binding = 1) uniform LightBuffer {
+layout(align = 16) Light lights[MAX_LIGHT_COUNT];
+} LightsBuffer;
+
 layout( push_constant ) uniform constants
 {
   uint lightCount;
@@ -21,15 +26,96 @@ 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(set = 0, binding = 4) uniform sampler2D shadowmapTexture;
 
 layout (location = 0) in vec2 inUV;
 layout(location = 1) in vec3 cameraPos;
 
 layout(location = 0) out vec4 outColor;
 
+mat4 get_orthographicMatrix(float l, float r, float b, float t, float f, float n)
+{
+  mat4 M = mat4(0);
+
+    // set OpenGL perspective projection matrix
+    M[0][0] = 2 / (r - l);
+    M[0][1] = 0;
+    M[0][2] = 0;
+    M[0][3] = 0;
+
+    M[1][0] = 0;
+    M[1][1] = -2 / (t - b);
+    M[1][2] = 0;
+    M[1][3] = 0;
+
+    M[2][0] = 0;
+    M[2][1] = 0;
+    M[2][2] = -2 / (f - n);
+    M[2][3] = 0;
+
+    M[0][3] = -(r + l) / (r - l);
+    M[1][3] = -(t + b) / (t - b);
+    M[2][3] = -(f + n) / (f - n);
+    M[3][3] = 1;
+
+    return M;
+}
+
+float textureProj(vec4 P, float bias, vec2 offset)
+{
+	float shadow = 1.0;
+	vec4 shadowCoord = P / P.w;
+	shadowCoord.st = shadowCoord.st * 0.5 + 0.5;
+
+
+	if (shadowCoord.z > -1.0 && shadowCoord.z < 1.0)
+	{
+		float dist = texture(shadowmapTexture, shadowCoord.st + offset).r;
+		if (shadowCoord.w > 0.0 && dist < shadowCoord.z - bias)
+		{
+			shadow = SHADOW_FACTOR;
+		}
+	}
+	return shadow;
+}
+
+float filterPCF(vec4 sc, float bias)
+{
+  ivec2 texDim = textureSize(shadowmapTexture, 0).xy;
+  float scale = 1.5;
+  float dx = scale * 1.0 / float(texDim.x);
+  float dy = scale * 1.0 / float(texDim.y);
+
+  float shadowFactor = 0.0;
+  int count = 0;
+  int range = 1;
+
+  for (int x = -range; x <= range; x++)
+  {
+    for (int y = -range; y <= range; y++)
+    {
+      shadowFactor += textureProj(sc, bias, vec2(dx*x, dy*y));
+      count++;
+    }
+  }
+
+  return shadowFactor / count;
+}
+
+vec4 shadow(vec3 fragcolor, float bias, vec3 fragpos)
+{
+  mat4 projectionMatrix = get_orthographicMatrix(-1, 1, -1, 1, 100, 0.1);
+  mat4 viewMatrix = inverse( LightsBuffer.lights[0].transform);
+  vec4 shadowClip	= projectionMatrix * viewMatrix * vec4(fragpos, 1.0);
+
+	float shadowFactor;
+	shadowFactor= filterPCF(shadowClip, bias);
+
+	fragcolor *= shadowFactor;
+
+	return vec4(fragcolor, 1.0);
+}
+
 void main()
 {
   vec4 gposition = texture(positionTexture, inUV);
@@ -37,6 +123,8 @@ void main()
   vec4 galbedo = texture(albedoTexture, inUV);
   vec4 gspec = texture(specularTexture, inUV);
 
+  vec4 shadowmap = texture(shadowmapTexture, inUV);
+
   vec3 position = gposition.xyz;
   vec3 normal = gnormal.xyz;
   vec3 albedo = galbedo.xyz;
@@ -53,13 +141,37 @@ void main()
   vec3 F  = fresnelSchlickRoughness(max(dot(normal, V), 0.0), F0, roughnessFactor);
 
   vec3 Lo = vec3(0);
-  for(int i = 0; i < PushConstants.lightCount; ++i)
+
+  {
+    Light directional_light = LightsBuffer.lights[0];
+
+    vec3 L = vec3(directional_light.transform[2]);
+    vec3 H = normalize(V + L);
+    vec3 radiance     = directional_light.color.xyz * directional_light.intensity;
+
+    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 += clamp((kD * albedo / PI + specular) * radiance * NdotL, vec3(0), vec3(1));
+  }
+
+  for(int i = 1; i < PushConstants.lightCount; ++i)
   {
     Light l = LightsBuffer.lights[i];
 
-    vec3 L = normalize(l.tranform[3].xyz - position);
+    vec3 L = normalize(l.transform[3].xyz - position);
     vec3 H = normalize(V + L);
-    float distance    = length(l.tranform[3].xyz - position);
+    float distance    = length(l.transform[3].xyz - position);
     float attenuation = 1.0 / (distance * distance);
     vec3 radiance     = l.color.xyz * attenuation * l.intensity;
 
@@ -82,11 +194,8 @@ void main()
   vec3 ambient = vec3(0.2) * albedo;
 
   vec3 color =  ambient + Lo;
-
   color += spec * specFactor;
 
-  // color = color / (color + vec3(1.0));
-
-  outColor = vec4(color, 1.0);
-  // outColor = vec4(spec * specFactor, 1.0);
+  float bias = 0.0000005;
+  outColor = shadow(color, bias, position);
 }