Proper (but unoptimized) PCF

assets/shaders/mesh.glsl

@@ -56,6 +56,11 @@ VERTEX_EXPORT VertexData {
   vec3 wPos;
 } VertexOut;
 
+float random(vec4 seed4) {
+  float dot_product = dot(seed4, vec4(12.9898,78.233,45.164,94.673));
+  return fract(sin(dot_product) * 43758.5453);
+}
+
 #if VERTEX_SHADER
 
 layout(location = 0) in vec3 aPos;
@@ -133,6 +138,12 @@ float lightAttenuation(float point, float dist, float radius) {
   return att;
 }
 
+vec2 poissonDisk[4] = vec2[](
+  vec2( -0.94201624, -0.39906216 ),
+  vec2( 0.94558609, -0.76890725 ),
+  vec2( -0.094184101, -0.92938870 ),
+  vec2( 0.34495938, 0.29387760 )
+);
 
 vec3 microfacetModel(Material mat, Light light, vec3 P, vec3 N) {
   vec3 diffuseBrdf = vec3(0); // metallic
@@ -166,9 +177,41 @@ vec3 microfacetModel(Material mat, Light light, vec3 P, vec3 N) {
   float NDotL = max(dot(N, L), 0);
   float NDotV = dot(N, V);
 
+  float shadow_mult = 1;
+  //// TODO: Shadows for directional light only for now
+  if (point == 0) {
+    vec4 shadow_pos = shadow_map_vp * vec4(VertexOut.wPos, 1.0);
+    shadow_pos /= shadow_pos.w;
+    shadow_pos.xyz = shadow_pos.xyz * 0.5 + 0.5; // [-1, 1] to [0, 1]
+    float bias = 0.005 * tan(acos(NDotL));
+    shadow_pos.z -= bias;
+
+    vec4 texcoord;
+    texcoord.xyw = shadow_pos.xyz; // sampler2DArrayShadow strange texcoord mapping
+    texcoord.z = 0; // First shadow map
+
+    float sum = 0;
+    vec2 tex_scale = 1.0 / vec2(textureSize(shadow_maps, 0));
+
+    for (float y = -1.5; y <= 1.5; y += 1) {
+      for (float x = -1.5; x <= 1.5; x += 1) {
+        sum += texture(shadow_maps, vec4(texcoord.xy + vec2(x, y) * tex_scale, texcoord.zw));
+      }
+    }
+
+    shadow_mult = sum / 16.0;
+
+    // for (int i=0; i<4; i++){
+    //   int index = int(16.0 * random(vec4(VertexOut.wPos.xyz * 1000.0, i))) % 4;
+    //   float depth_test = texture(shadow_maps, vec4(texcoord.xy + poissonDisk[index]/700.0, texcoord.zw));
+    //   shadow_mult -= 0.25 * (1 - depth_test);
+    // }
+    //shadow_mult = texture(shadow_maps, texcoord);
+  }
+
   vec3 specBrdf = 0.25 * ggxDistribution(mat, NDotH) * schlickFresnel(mat, LDotH) * geomSmith(mat, NDotL) * geomSmith(mat, NDotV);
 
-  return (diffuseBrdf + PI * specBrdf) * lightI * NDotL;
+  return (diffuseBrdf + PI * specBrdf) * lightI * NDotL * shadow_mult;
 }
 
 void main() {
@@ -183,23 +226,7 @@ void main() {
   vec3 finalColor = vec3(0);
 
   for (int i = 0; i < lights_count; i++) {
-    float shadow_mult = 1;
-
-    //// TODO: Shadows for directional light only for now
-    if (lights[i].vPos.w == 0) {
-      vec4 shadow_pos = shadow_map_vp * vec4(VertexOut.wPos, 1.0);
-      shadow_pos /= shadow_pos.w;
-      shadow_pos.xyz = shadow_pos.xyz * 0.5 + 0.5; // [-1, 1] to [0, 1]
-      float bias = 0.005;
-      shadow_pos.z -= bias;
-
-      vec4 texcoord;
-      texcoord.xyw = shadow_pos.xyz; // sampler2DArrayShadow strange texcoord mapping
-      texcoord.z = 0; // First shadow map
-
-      shadow_mult = texture(shadow_maps, texcoord).r;
-    }
-    finalColor += microfacetModel(material, lights[i], VertexOut.vPos, N) * shadow_mult;
+    finalColor += microfacetModel(material, lights[i], VertexOut.vPos, N);
   }
 
   FragColor = vec4(finalColor, 1.0f);

src/Render.zig

@@ -141,15 +141,16 @@ pub fn init(allocator: std.mem.Allocator, frame_arena: std.mem.Allocator, assetm
         checkGLError();
         std.debug.assert(render.shadow_texture_arrray != 0);
 
-        gl.textureStorage3D(render.shadow_texture_arrray, 1, gl.DEPTH_COMPONENT16, 1024, 1024, 1);
+        gl.textureStorage3D(render.shadow_texture_arrray, 1, gl.DEPTH_COMPONENT16, 2048, 2048, 1);
         checkGLError();
 
         gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_COMPARE_MODE, gl.COMPARE_REF_TO_TEXTURE);
-        //gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_COMPARE_FUNC, gl.LEQUAL);
-        gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
-        gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+        gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_COMPARE_FUNC, gl.LESS);
+        gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_BORDER);
+        gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_BORDER);
         gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
         gl.textureParameteri(render.shadow_texture_arrray, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+        gl.textureParameterfv(render.shadow_texture_arrray, gl.TEXTURE_BORDER_COLOR, @ptrCast(&Vec4.one().data));
 
         // First shadow texture handle
         render.shadow_texture_handle = gl.GL_ARB_bindless_texture.getTextureHandleARB(render.shadow_texture_arrray);
@@ -270,7 +271,7 @@ pub fn finish(self: *Render) void {
     // Directional Light shadow map
     if (dir_light) |light| {
         gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, self.shadow_framebuffer);
-        gl.viewport(0, 0, 1024, 1024);
+        gl.viewport(0, 0, 2048, 2048);
         gl.clear(gl.DEPTH_BUFFER_BIT);
 
         gl.useProgram(self.assetman.resolveShaderProgram(a.ShaderPrograms.shaders.shadow).program);
@@ -278,7 +279,7 @@ pub fn finish(self: *Render) void {
 
         const camera_matrix = &self.shadow_matrices;
         camera_matrix.* = .{
-            .projection = Mat4.orthographic(-5, 5, -5, 5, -10, 10),
+            .projection = Mat4.orthographic(-2, 2, -2, 2, -5, 5),
             .view = Mat4.lookAt(
                 Vec3.new(light.pos.x(), light.pos.y(), light.pos.z()).scale(-1),
                 Vec3.zero(),

src/game.zig

@@ -189,7 +189,6 @@ export fn game_init(global_allocator: *std.mem.Allocator) void {
         .flags = .{ .dir_light = true, .rotate = true },
         .transform = .{ .rot = Quat.fromEulerAngles(Vec3.new(60, 15, 0)) },
         .light = .{ .color_intensity = Vec4.new(1, 1, 0.83, 1) },
-        .rotate = .{ .rate = 45, .axis = Vec3.up() },
     });
 
     const light_root = globals.g_mem.world.addEntity(.{