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.nix

@@ -19,14 +19,13 @@
       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 vulkan-validation-layers]);
+        LD_LIBRARY_PATH = lib.makeLibraryPath (with pkgs; [SDL2 vulkan-loader]);
         buildInputs = with pkgs; [
           SDL2
           SDL2.dev
           vulkan-headers
           vulkan-loader
           vulkan-validation-layers # maybe?
-          shaderc
           # glm and whatnot …
         ];
       };

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,
@@ -73,6 +84,11 @@ 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;
@@ -107,4 +123,5 @@ void main() {
   // z normalization
   //gl_Position.z /= zFar;
   gl_Position *= project_normal;
+
 }

src/main.rs

@@ -828,6 +828,7 @@ fn write_desc_sets(
     desc_sets: &Vec<vk::DescriptorSet>,
     mesh_buf: &vk::Buffer,
     image_view: vk::ImageView,
+    skybox_sampler: vk::Sampler
 ) {
     let buf_info = vk::DescriptorBufferInfo::default()
         .buffer(*mesh_buf)
@@ -842,8 +843,9 @@ fn write_desc_sets(
         .buffer_info(&buf_infos);
 
     let img_info = vk::DescriptorImageInfo::default()
-        .image_layout(vk::ImageLayout::UNDEFINED)
+        .image_layout(vk::ImageLayout::GENERAL)
-        .image_view(image_view);
+        .image_view(image_view)
+        .sampler(skybox_sampler);
     let img_infos = &[img_info];
     let img_desc = vk::WriteDescriptorSet::default()
         .dst_set(desc_sets[0])
@@ -944,6 +946,30 @@ fn record_commands(
         .clear_values(&clear_vals);
 
     unsafe {
+        let regions = (0..6)
+        .map(|i| {
+            vk::BufferImageCopy::default()
+                .buffer_offset(3 * 2048 * 2048 * i)
+                .buffer_row_length(0)
+                .buffer_image_height(0)
+                .image_offset(vk::Offset3D::default())
+                .image_extent(vk::Extent3D::default().width(2048).height(2048).depth(1))
+                .image_subresource(
+                    vk::ImageSubresourceLayers::default()
+                        .aspect_mask(vk::ImageAspectFlags::COLOR)
+                        .mip_level(0)
+                        .layer_count(1)
+                        .base_array_layer(i as u32),
+                )
+        })
+        .collect::<Vec<_>>();
+        dev.cmd_copy_buffer_to_image(
+            *cmd_buf,
+            *skybox_buffer,
+            *skybox_image,
+            vk::ImageLayout::GENERAL,
+            &regions,
+        );
         dev.cmd_begin_render_pass(*cmd_buf, &render_pass_info, vk::SubpassContents::INLINE);
         dev.cmd_bind_pipeline(*cmd_buf, vk::PipelineBindPoint::GRAPHICS, *pipe);
         dev.cmd_bind_descriptor_sets(
@@ -1011,30 +1037,7 @@ fn record_commands(
             base_color.as_ref(),
         );
 
-        let regions = (0..6)
+
-            .map(|i| {
-                vk::BufferImageCopy::default()
-                    .buffer_offset(3 * 2048 * 2048 * i)
-                    .buffer_row_length(0)
-                    .buffer_image_height(0)
-                    .image_offset(vk::Offset3D::default())
-                    .image_extent(vk::Extent3D::default().width(2048).height(2048).depth(1))
-                    .image_subresource(
-                        vk::ImageSubresourceLayers::default()
-                            .aspect_mask(vk::ImageAspectFlags::COLOR)
-                            .mip_level(0)
-                            .layer_count(1)
-                            .base_array_layer(i as u32),
-                    )
-            })
-            .collect::<Vec<_>>();
-        dev.cmd_copy_buffer_to_image(
-            *cmd_buf,
-            *skybox_buffer,
-            *skybox_image,
-            vk::ImageLayout::GENERAL,
-            &regions,
-        );
 
         dev.cmd_draw(*cmd_buf, 36, 1, 0, 0);
         dev.cmd_end_render_pass(*cmd_buf);
@@ -1144,7 +1147,7 @@ fn handle_cont_key(keycode: Keycode, camera: &mut Camera, mouse: &MouseUtil) {
 }
 
 fn decode_rif(raw: &[u8]) -> &[u8] {
-    &raw[18..]
+    &raw[17..]
 }
 
 fn main() {
@@ -1222,7 +1225,7 @@ fn main() {
     unsafe {
         std::ptr::copy(POSITIONS.as_ptr(), mesh_mem as *mut f32, POSITIONS.len());
     }
-
+    
     let (skybox_image, skybox_image_view, skybox_sampler) = {
         let qf_idxs = [rcs_queue_inx];
         let create_info = vk::ImageCreateInfo::default()
@@ -1236,10 +1239,16 @@ fn main() {
             .tiling(vk::ImageTiling::OPTIMAL)
             .usage(vk::ImageUsageFlags::TRANSFER_DST | vk::ImageUsageFlags::SAMPLED)
             .sharing_mode(vk::SharingMode::EXCLUSIVE)
-            .initial_layout(vk::ImageLayout::GENERAL)
+            .initial_layout(vk::ImageLayout::UNDEFINED)
             .queue_family_indices(&qf_idxs);
         let image =
             unsafe { dev.create_image(&create_info, None) }.expect("Failed to create image");
+        
+        let skybox_mem_size: vk::MemoryRequirements = unsafe {dev.get_image_memory_requirements(image)};
+        let skybox_dev_mem = mem_alloc(&dev, host_invisible_inx, skybox_mem_size.size);
+        unsafe {
+            dev.bind_image_memory(image, skybox_dev_mem, 0).expect("Failed to bind image memory");
+        }
         let create_info = vk::ImageViewCreateInfo::default()
             .image(image)
             .view_type(vk::ImageViewType::CUBE)
@@ -1268,6 +1277,7 @@ fn main() {
         let sampler =
             unsafe { dev.create_sampler(&create_info, None) }.expect("Failed to create sampler");
 
+
         (image, image_view, sampler)
     };
 
@@ -1343,7 +1353,7 @@ fn main() {
 
     let desc_sets = make_desc_sets(&dev, &desc_pool);
 
-    write_desc_sets(&dev, &desc_sets, &mesh_buf, skybox_image_view);
+    write_desc_sets(&dev, &desc_sets, &mesh_buf, skybox_image_view, skybox_sampler);
 
     let sem_avail = make_sem(&dev);
     let sem_finish = make_sem(&dev);