Skybox rendering

Work-in-progress: Currently the main shaders were hijacked to avoid
writing the rest of the code for handling this
Broken: Validation does not pass; We need pipeline barriers to convert
the layout. Also the image has seams.
Co-Author: Avery, I did the fixups after + reading of the docs, she
wrote the code :3

flake.lock

@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1743315132,
+        "narHash": "sha256-6hl6L/tRnwubHcA4pfUUtk542wn2Om+D4UnDhlDW9BE=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "52faf482a3889b7619003c0daec593a1912fddc1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,33 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    flake-utils,
+  } @ inputs:
+    flake-utils.lib.eachDefaultSystem (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+      };
+      lib = nixpkgs.lib;
+    in {
+      devShells.default = pkgs.mkShell {
+        VULKAN_SDK = "${pkgs.vulkan-validation-layers}/share/vulkan/explicit_layer.d";
+        # LD_LIBRARY_PATH = "$LD_LIBRARY_PATH:${pkgs.SDL2}/lib/";
+        LD_LIBRARY_PATH = lib.makeLibraryPath (with pkgs; [SDL2 vulkan-loader]);
+        buildInputs = with pkgs; [
+          SDL2
+          SDL2.dev
+          vulkan-headers
+          vulkan-loader
+          vulkan-validation-layers # maybe?
+          # glm and whatnot …
+        ];
+      };
+    });
+}

shaders/frag.frag

@@ -1,4 +1,7 @@
 #version 450
+// vim: ft=c
+//
+layout(binding = 1) uniform samplerCube combined_image;
 
 layout(location = 0) out vec4 outColor;
 
@@ -10,7 +13,8 @@ layout(push_constant, std430) uniform pc {
 };
 
 void main() {
-  outColor = vec4(data.rgb*(1.0+dot(normal.xyz, normalize(vec3(-0.7, -0.5, -0.1))))/2.0, 1.0);
+  outColor = texture(combined_image, vec3(pos_pre));
+  // outColor = vec4(data.rgb*(1.0+dot(normal.xyz, normalize(vec3(-0.7, -0.5, -0.1))))/2.0, 1.0);
 //if(pos_post.z <= 0.0) {
 //  outColor = vec4(1.0);
 //}

shaders/vert.vert

@@ -1,8 +1,13 @@
 #version 450
 // vim: ft=c
 
+struct PosNorm {
+    vec4 pos;
+    vec4 norm;
+};
+
 layout(std430, set = 0, binding = 0) buffer positions_buffer {
-	mat2x4 posnrm[];
+	PosNorm posnrm[];
 } pos;
 
 layout(push_constant, std430) uniform pc {
@@ -20,16 +25,22 @@ const float TAU = PI*2.0;
 
 void main() {
   // assign outs
-  normal = pos.posnrm[gl_VertexIndex][1];
+  normal = pos.posnrm[gl_VertexIndex].norm;
-  pos_pre = pos.posnrm[gl_VertexIndex][0];
+  pos_pre = pos.posnrm[gl_VertexIndex].pos;
 
   // define constants
   const float zFar = 100.0;
   const float zNear = 0.1;
 
   // assign the transformee
-  gl_Position = pos.posnrm[gl_VertexIndex][0];
+  gl_Position = pos.posnrm[gl_VertexIndex].pos;
 
+  mat4 fix_coordinates = mat4(
+    -1.0, 0.0, 0.0, 0.0,
+    0.0, -1.0, 0.0, 0.0,
+    0.0, 0.0, -1.0, 0.0,
+    0.0, 0.0, 0.0, 1.0
+  );
   mat4 view_orig = mat4(
     1.0, 0.0, 0.0, cam_orig.x,
     0.0, 1.0, 0.0, cam_orig.y,
@@ -73,9 +84,14 @@ void main() {
     0.0, 0.0, 0.0, 1.0
   );
 
+  // vulkan has inverted screen coordinates
+  // but we want regular mesh coordinates
+  // gl_Position.xyz *= -1.0
+  gl_Position *= fix_coordinates;
+
   // apply view's origin transformation 
   //gl_Position.xyz += cam_orig.xyz;
-  gl_Position *= view_orig;
+  // gl_Position *= view_orig;
 
   // apply view's xz rotation
   //mat2 xz_rot;
@@ -107,4 +123,5 @@ void main() {
   // z normalization
   //gl_Position.z /= zFar;
   gl_Position *= project_normal;
+
 }