feat: add HDRI

4 files changed, 80 insertions, 2 deletions

diff --git a/assets/shaders/equirect_to_cubemap.glsl b/assets/shaders/equirect_to_cubemap.glsl
new file mode 100644
index 0000000..2b99c9b
--- /dev/null
+++ b/assets/shaders/equirect_to_cubemap.glsl
@@ -0,0 +1,33 @@
+#type vertex
+
+#version 330 core
+layout (location = 0) in vec3 aPos;
+out vec3 WorldPos;
+uniform mat4 projection;
+uniform mat4 view;
+void main()
+{
+    WorldPos = aPos;
+    gl_Position = projection * view * vec4(WorldPos, 1.0);
+}
+
+#type fragment
+
+#version 330 core
+out vec4 FragColor;
+in vec3 WorldPos;
+uniform sampler2D equirectangularMap;
+const vec2 invAtan = vec2(0.1591, 0.3183);
+vec2 SampleSphericalMap(vec3 v)
+{
+    vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
+    uv *= invAtan;
+    uv += 0.5;
+    return uv;
+}
+void main()
+{
+    vec2 uv = SampleSphericalMap(normalize(WorldPos));
+    vec3 color = texture(equirectangularMap, uv).rgb;
+    FragColor = vec4(color, 1.0);
+}
diff --git a/assets/shaders/geodesic.glsl b/assets/shaders/geodesic.glsl
index 70e41ef..2e69c72 100644
--- a/assets/shaders/geodesic.glsl
+++ b/assets/shaders/geodesic.glsl
@@ -2,6 +2,7 @@
 layout(local_size_x = 16, local_size_y = 16) in;
 
 layout(binding = 0, rgba8) writeonly uniform image2D outImage;
+layout(binding = 5) uniform samplerCube u_HDRIEnvironment;
 layout(std140, binding = 1) uniform Camera 
 {
     vec3  camPos;     float _pad0;
@@ -55,6 +56,11 @@ vec4 objectColor = vec4(0.0);
 vec3 hitCenter = vec3(0.0);
 float hitRadius = 0.0;
 
+vec3 SampleHDRI(vec3 direction)
+{
+    return texture(u_HDRIEnvironment, direction).rgb;
+}
+
 float hash(float p) 
 {
     p = fract(p * 0.1031);
@@ -471,7 +477,11 @@ void main()
         color = vec4(shaded, objectColor.a);
         color = mix(accumulatedColor, color, color.a);
     } else
-        color = accumulatedColor;
+    {
+        vec3 rayDirection = normalize(vec3(ray.x, ray.y, ray.z) - cam.camPos);
+        vec3 hdriColor = SampleHDRI(rayDirection);
+        color  = vec4(mix(accumulatedColor.rgb, hdriColor, 1.0 - accumulatedColor.a), 1.0);
+    }
 
     imageStore(outImage, pix, color);
 }
diff --git a/assets/shaders/skybox.glsl b/assets/shaders/skybox.glsl
new file mode 100644
index 0000000..654bed1
--- /dev/null
+++ b/assets/shaders/skybox.glsl
@@ -0,0 +1,31 @@
+#type vertex
+
+#version 330 core
+
+layout (location = 0) in vec3 aPos;
+
+out vec3 TexCoords;
+
+uniform mat4 u_Projection;
+uniform mat4 u_View;
+
+void main()
+{
+    TexCoords   = aPos;
+    vec4 pos    = u_Projection * u_View * vec4(aPos, 1.0);
+    gl_Position = pos.xyww;
+}
+
+#type fragment
+
+#version 330 core
+
+out vec4 FragColor;
+in  vec3 TexCoords;
+
+uniform samplerCube u_Skybox;
+
+void main()
+{
+    FragColor = texture(u_Skybox, TexCoords);
+}
diff --git a/assets/shaders/sphere.glsl b/assets/shaders/sphere.glsl
index 23e8f54..2d1a46e 100644
--- a/assets/shaders/sphere.glsl
+++ b/assets/shaders/sphere.glsl
@@ -33,6 +33,7 @@ uniform vec3  u_CameraPos;
 uniform int   u_IsSelected;
 uniform vec3  u_OutlineColor;
 uniform float u_OutlineWidth;
+uniform samplerCube u_HDRIEnvironment;
 
 out vec4 o_FragColor;
 
@@ -43,10 +44,13 @@ void main()
     vec3 viewDir    = normalize(u_CameraPos - v_WorldPos);
     vec3 reflectDir = reflect(-lightDir, normal);
     
+    vec3 hdriLight = texture(u_HDRIEnvironment, normal).rgb;
+    float hdriIntensity = 0.3;
+    
     float diff = max(dot(normal, lightDir), 0.0);
     float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32.0);
     
-    vec3 diffuse  = u_Color * diff;
+    vec3 diffuse  = u_Color * (diff + hdriIntensity * hdriLight);
     vec3 specular = vec3(u_Specular) * spec;
     vec3 emission = u_Color * u_Emission;