Experiment with subpasses

assets/models/tescoPiwo.mtl

@@ -0,0 +1,13 @@
+# Blender 4.2.0 MTL File: 'tescoPiwo.blend'
+# www.blender.org
+
+newmtl Material.001
+Ns 360.000000
+Ka 0.500000 0.500000 0.500000
+Ks 0.500000 0.500000 0.500000
+Ke 0.000000 0.000000 0.000000
+Ni 1.500000
+d 1.000000
+illum 3
+map_Kd tescoPiwoTexture.png
+map_Bump -bm 1.000000 /home/przmk/Downloads/Downloads/tescoPiwoNormal.png

build.zig

@@ -1,6 +1,6 @@
 const std = @import("std");
-const sdl = @import("libs/sdl/build.zig");
+const sdl = @import("sdl");
-const vkgen = @import("vulkan_zig");
+const vkgen = @import("vulkan");
 
 pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
@@ -20,7 +20,7 @@ pub fn build(b: *std.Build) void {
     // --- Dependencies ---
 
     // Vulkan
-    const vkzig_dep = b.dependency("vulkan_zig", .{
+    const vkzig_dep = b.dependency("vulkan", .{
         .registry = @as([]const u8, b.pathFromRoot("./vk.xml")),
     });
     const vkzig_bindings = vkzig_dep.module("vulkan-zig");
@@ -34,12 +34,12 @@ pub fn build(b: *std.Build) void {
     );
     shader_comp.add("shader_frag", "src/shaders/shader.frag", .{});
     shader_comp.add("shader_vert", "src/shaders/shader.vert", .{});
-    shader_comp.add("shader_frag", "src/shaders/second.frag", .{});
+    shader_comp.add("second_frag", "src/shaders/second.frag", .{});
-    shader_comp.add("shader_vert", "src/shaders/second.vert", .{});
+    shader_comp.add("second_vert", "src/shaders/second.vert", .{});
     exe.root_module.addImport("shaders", shader_comp.getModule());
 
     // SDL2
-    const sdl_sdk = sdl.init(b, null, null);
+    const sdl_sdk = sdl.init(b, .{});
     sdl_sdk.link(exe, .dynamic, sdl.Library.SDL2);
     exe.root_module.addImport("sdl2", sdl_sdk.getWrapperModuleVulkan(vkzig_bindings));
 

build.zig.zon

@@ -6,9 +6,10 @@
     .dependencies = .{
         .zmath = .{ .path = "libs/zmath" },
         .zstbi = .{ .path = "libs/zstbi" },
-        .vulkan_zig = .{
+        .sdl = .{ .path = "libs/sdl" },
-            .url = "https://github.com/Snektron/vulkan-zig/archive/18f38ef2b7ae394734bd8b28d43f120f2b9567c1.tar.gz",
+        .vulkan = .{
-            .hash = "1220530d62adb3f7ab87bacde31c302955a5803db52e302a0c7f8e107ca03f7aeca5",
+            .url = "https://github.com/Snektron/vulkan-zig/archive/f7b21d034f527765f62935de1b62855033621989.tar.gz",
+            .hash = "12201e484e173e70634e664864763223427703e677f28c63ebec9332513c8ca5121c",
         },
         .obj = .{
             .url = "https://github.com/chip2n/zig-obj/archive/58f524ed6834790b29ac1e97b2f9e6b7de7b5346.tar.gz",

libs/sdl

@@ -1 +1 @@
-Subproject commit 9663dc70c19b13afcb4b9f596c928d7b2838e548
+Subproject commit 172a84e7b5ce7d4891b8b970c68f4532f96aa7e9

libs/zmath/src/zmath.zig

@@ -329,7 +329,7 @@ pub inline fn boolx16(
 // zig fmt: on
 
 pub inline fn veclen(comptime T: type) comptime_int {
-    return @typeInfo(T).Vector.len;
+    return @typeInfo(T).vector.len;
 }
 
 pub inline fn splat(comptime T: type, value: f32) T {
@@ -413,14 +413,14 @@ pub inline fn storeArr4(arr: *[4]f32, v: F32x4) void {
 }
 
 pub inline fn arr3Ptr(ptr: anytype) *const [3]f32 {
-    comptime assert(@typeInfo(@TypeOf(ptr)) == .Pointer);
+    comptime assert(@typeInfo(@TypeOf(ptr)) == .pointer);
     const T = std.meta.Child(@TypeOf(ptr));
     comptime assert(T == F32x4);
     return @as(*const [3]f32, @ptrCast(ptr));
 }
 
 pub inline fn arrNPtr(ptr: anytype) [*]const f32 {
-    comptime assert(@typeInfo(@TypeOf(ptr)) == .Pointer);
+    comptime assert(@typeInfo(@TypeOf(ptr)) == .pointer);
     const T = std.meta.Child(@TypeOf(ptr));
     comptime assert(T == Mat or T == F32x4 or T == F32x8 or T == F32x16);
     return @as([*]const f32, @ptrCast(ptr));

src/main.zig

@@ -71,7 +71,7 @@ pub fn main() !void {
     var angle: f32 = 0.0;
     const move_speed: f32 = 1000;
 
-    const model_handle = try vulkan_renderer.createMeshModel("teapot.obj");
+    const model_handle = try vulkan_renderer.createMeshModel("tescoPiwo.obj");
 
     mainLoop: while (true) {
         while (sdl.pollEvent()) |ev| {

src/shaders/second.frag

@@ -2,12 +2,21 @@
 
 // Colour output from subpass 1
 layout(input_attachment_index = 0, binding = 0) uniform subpassInput inputColour;
-
 // Depth output from subpass 1
 layout(input_attachment_index = 1, binding = 1) uniform subpassInput inputDepth;
 
 layout(location = 0) out vec4 colour;
 
 void main() {
-    colour = subpassLoad(inputColour).rgba;
+    int xHalf = 800 / 2; 
+    if (gl_FragCoord.x > xHalf) {
+        float lowerBound = 0.98;
+        float upperBound = 1;
+
+        float depth = subpassLoad(inputDepth).r;
+        float depthColourScaled = 1.0f - ((depth - lowerBound) / (upperBound - lowerBound));
+        colour  = vec4(subpassLoad(inputColour).rgb * depthColourScaled, 1.0f);
+    } else {
+        colour = subpassLoad(inputColour).rgba;
+    }
 }

src/shaders/second.vert

@@ -4,7 +4,7 @@
 vec2 positions[3] = vec2[](
     vec2(3.0, -1.0),
     vec2(-1.0, -1.0),
-    vec2(-1.0, 3.0),
+    vec2(-1.0, 3.0)
 );
 
 void main() {

src/vulkan_renderer.zig

@@ -101,7 +101,7 @@ pub const VulkanRenderer = struct {
     input_descriptor_pool: vk.DescriptorPool,
     descriptor_sets: []vk.DescriptorSet,
     sampler_descriptor_sets: std.ArrayList(vk.DescriptorSet),
-    input_descriptor_sets: std.ArrayList(vk.DescriptorSet),
+    input_descriptor_sets: []vk.DescriptorSet,
 
     vp_uniform_buffer: []vk.Buffer,
     vp_uniform_buffer_memory: []vk.DeviceMemory,
@@ -167,7 +167,6 @@ pub const VulkanRenderer = struct {
         try self.createCommandPool();
 
         self.sampler_descriptor_sets = try std.ArrayList(vk.DescriptorSet).initCapacity(self.allocator, self.swapchain_images.len);
-        self.input_descriptor_sets = try std.ArrayList(vk.DescriptorSet).initCapacity(self.allocator, self.swapchain_images.len);
 
         try self.createCommandBuffers();
         try self.createTextureSampler();
@@ -330,6 +329,7 @@ pub const VulkanRenderer = struct {
         self.device.destroyDescriptorSetLayout(self.sampler_set_layout, null);
         self.device.destroyDescriptorSetLayout(self.input_set_layout, null);
         self.sampler_descriptor_sets.deinit();
+        self.allocator.free(self.input_descriptor_sets);
 
         for (0..self.swapchain_images.len) |i| {
             self.device.destroyBuffer(self.vp_uniform_buffer[i], null);
@@ -354,6 +354,8 @@ pub const VulkanRenderer = struct {
 
         self.allocator.free(self.swapchain_framebuffers);
 
+        self.device.destroyPipeline(self.second_pipeline, null);
+        self.device.destroyPipelineLayout(self.second_pipeline_layout, null);
         self.device.destroyPipeline(self.graphics_pipeline, null);
         self.device.destroyPipelineLayout(self.pipeline_layout, null);
         self.device.destroyRenderPass(self.render_pass, null);
@@ -556,7 +558,7 @@ pub const VulkanRenderer = struct {
     fn createRenderPass(self: *Self) !void {
         // -- Attachments --
 
-        const subpasses: [2]vk.SubpassDescription = undefined;
+        var subpasses: [2]vk.SubpassDescription = undefined;
 
         // Subpass 1 attachments and references (input attachments)
 
@@ -569,7 +571,7 @@ pub const VulkanRenderer = struct {
             .{ .color_attachment_bit = true },
         );
         const colour_attachment: vk.AttachmentDescription = .{
-            .format = colour_format,
+            .format = colour_format.?,
             .samples = .{ .@"1_bit" = true },
             .load_op = .clear,
             .store_op = .dont_care,
@@ -657,7 +659,7 @@ pub const VulkanRenderer = struct {
         // Need to determine when layout transitions occur using subpass dependencies
         const subpass_dependencies = [_]vk.SubpassDependency{
             // Conversion from VK_IMAGE_LAYOUT_UNDEFINED to VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL
-            vk.SubpassDependency{
+            .{
                 // Transition must happen after...
                 .src_subpass = vk.SUBPASS_EXTERNAL, // Subpass index (VK_SUBPASS_EXTERNAL = outside of renderpass)
                 .src_stage_mask = .{ .bottom_of_pipe_bit = true }, // Pipeline stage
@@ -677,7 +679,7 @@ pub const VulkanRenderer = struct {
                 .dst_access_mask = .{ .shader_read_bit = true },
             },
             // Conversion from VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL to VK_IMAGE_LAYOUT_PRESENT_SRC_KHR
-            vk.SubpassDependency{
+            .{
                 // Transition must happen after...
                 .src_subpass = 0,
                 .src_stage_mask = .{ .color_attachment_output_bit = true },
@@ -840,7 +842,7 @@ pub const VulkanRenderer = struct {
                 self.extent.height,
                 self.depth_format,
                 .optimal,
-                .{ .depth_stencil_attachment_bit = true },
+                .{ .depth_stencil_attachment_bit = true, .input_attachment_bit = true },
                 .{ .device_local_bit = true },
                 &self.depth_buffer_image_memory[i],
             );
@@ -867,14 +869,14 @@ pub const VulkanRenderer = struct {
         // -- Shader stage creation information --
 
         // Vertex stage creation information
-        const vertex_shader_create_info: vk.PipelineShaderStageCreateInfo = .{
+        var vertex_shader_create_info: vk.PipelineShaderStageCreateInfo = .{
             .stage = .{ .vertex_bit = true },
             .module = vert,
             .p_name = "main",
         };
 
         // Fragment stage creation information
-        const fragment_shader_create_info: vk.PipelineShaderStageCreateInfo = .{
+        var fragment_shader_create_info: vk.PipelineShaderStageCreateInfo = .{
             .stage = .{ .fragment_bit = true },
             .module = frag,
             .p_name = "main",
@@ -920,7 +922,7 @@ pub const VulkanRenderer = struct {
         };
 
         // -- Vertex input --
-        const vertex_input_create_info: vk.PipelineVertexInputStateCreateInfo = .{
+        var vertex_input_create_info: vk.PipelineVertexInputStateCreateInfo = .{
             .vertex_binding_description_count = 1,
             .p_vertex_binding_descriptions = @ptrCast(&binding_description), // List of vertex binding descriptions (data spacing, stride info)
             .vertex_attribute_description_count = @intCast(attribute_descriptions.len),
@@ -1026,7 +1028,7 @@ pub const VulkanRenderer = struct {
         self.pipeline_layout = try self.device.createPipelineLayout(&pipeline_layout_create_info, null);
 
         // -- Depth stencil testing --
-        const depth_stencil_create_info: vk.PipelineDepthStencilStateCreateInfo = .{
+        var depth_stencil_create_info: vk.PipelineDepthStencilStateCreateInfo = .{
             .depth_test_enable = vk.TRUE, // Enable checking depth to determine fragment write
             .depth_write_enable = vk.TRUE, // Enable writing to depth buffer to replace all values
             .depth_compare_op = .less, // Comparison operation that allows an overwrite (is in front)
@@ -1039,7 +1041,7 @@ pub const VulkanRenderer = struct {
         };
 
         // -- Graphics pipeline creation --
-        const pipeline_create_info: vk.GraphicsPipelineCreateInfo = .{
+        var pipeline_create_info: vk.GraphicsPipelineCreateInfo = .{
             .stage_count = @intCast(shader_create_infos.len), // Number of shader stages
             .p_stages = &shader_create_infos, // List of shader stages
             .p_vertex_input_state = &vertex_input_create_info,
@@ -1070,13 +1072,13 @@ pub const VulkanRenderer = struct {
         // Second pass shaders
         const second_vert_shader_module = try self.device.createShaderModule(&.{
             .code_size = shaders.second_vert.len,
-            .p_code = @ptrCast(&shaders.shader_vert),
+            .p_code = @ptrCast(&shaders.second_vert),
         }, null);
         defer self.device.destroyShaderModule(second_vert_shader_module, null);
 
         const second_frag_shader_module = try self.device.createShaderModule(&.{
             .code_size = shaders.second_frag.len,
-            .p_code = @ptrCast(&shaders.shader_frag),
+            .p_code = @ptrCast(&shaders.second_frag),
         }, null);
         defer self.device.destroyShaderModule(second_frag_shader_module, null);
 
@@ -1084,7 +1086,7 @@ pub const VulkanRenderer = struct {
         vertex_shader_create_info.module = second_vert_shader_module;
         fragment_shader_create_info.module = second_frag_shader_module;
 
-        const second_shader_stages = []vk.PipelineShaderStageCreateInfo{ vertex_shader_create_info, fragment_shader_create_info };
+        const second_shader_stages = [_]vk.PipelineShaderStageCreateInfo{ vertex_shader_create_info, fragment_shader_create_info };
 
         // No vertex data for second pass
         vertex_input_create_info.vertex_binding_description_count = 0;
@@ -1098,7 +1100,7 @@ pub const VulkanRenderer = struct {
         // Create new pipeline layout
         const second_pipeline_layout_create_info: vk.PipelineLayoutCreateInfo = .{
             .set_layout_count = 1,
-            .p_set_layouts = @ptrCast(self.input_set_layout),
+            .p_set_layouts = @ptrCast(&self.input_set_layout),
         };
 
         self.second_pipeline_layout = try self.device.createPipelineLayout(&second_pipeline_layout_create_info, null);
@@ -1107,6 +1109,15 @@ pub const VulkanRenderer = struct {
         pipeline_create_info.p_stages = &second_shader_stages;
         pipeline_create_info.layout = self.second_pipeline_layout;
         pipeline_create_info.subpass = 1;
+
+        // Create second pipeline
+        _ = try self.device.createGraphicsPipelines(
+            .null_handle,
+            1,
+            @ptrCast(&pipeline_create_info),
+            null,
+            @ptrCast(&self.second_pipeline),
+        );
     }
 
     fn createFramebuffers(self: *Self) !void {
@@ -1282,7 +1293,7 @@ pub const VulkanRenderer = struct {
 
         // Create input attachment pool
         const input_pool_create_info: vk.DescriptorPoolCreateInfo = .{
-            .max_sets = self.swapchain_images.len,
+            .max_sets = @intCast(self.swapchain_images.len),
             .pool_size_count = @intCast(input_pool_sizes.len),
             .p_pool_sizes = &input_pool_sizes,
         };
@@ -1341,6 +1352,8 @@ pub const VulkanRenderer = struct {
     }
 
     fn createInputDescriptorSets(self: *Self) !void {
+        self.input_descriptor_sets = try self.allocator.alloc(vk.DescriptorSet, self.swapchain_images.len);
+
         // Fill array of layouts ready for set creation
         var set_layouts = try self.allocator.alloc(vk.DescriptorSetLayout, self.swapchain_images.len);
         defer self.allocator.free(set_layouts);
@@ -1352,46 +1365,50 @@ pub const VulkanRenderer = struct {
         const set_alloc_info: vk.DescriptorSetAllocateInfo = .{
             .descriptor_pool = self.input_descriptor_pool,
             .descriptor_set_count = @intCast(self.swapchain_images.len),
-            .p_set_layouts = &set_layouts,
+            .p_set_layouts = set_layouts.ptr,
         };
 
         // Allocate descriptor sets
-        try self.device.allocateDescriptorSets(&set_alloc_info, self.input_descriptor_sets.items.ptr);
+        try self.device.allocateDescriptorSets(&set_alloc_info, self.input_descriptor_sets.ptr);
 
         // Update each descriptor set with input attachment
         for (0..self.swapchain_images.len) |i| {
             // Colour attachment descriptor
             const colour_attachment_descriptor: vk.DescriptorImageInfo = .{
-                .image_layout = .read_only_optimal,
+                .image_layout = .shader_read_only_optimal,
                 .image_view = self.colour_buffer_image_view[i],
                 .sampler = .null_handle,
             };
 
             // Colour attachment descriptor write
             const colour_write: vk.WriteDescriptorSet = .{
-                .dst_set = self.input_descriptor_sets.items[i],
+                .dst_set = self.input_descriptor_sets[i],
                 .dst_binding = 0,
                 .dst_array_element = 0,
                 .descriptor_type = .input_attachment,
                 .descriptor_count = 1,
                 .p_image_info = @ptrCast(&colour_attachment_descriptor),
+                .p_buffer_info = undefined,
+                .p_texel_buffer_view = undefined,
             };
 
             // Depth attachment descriptor
             const depth_attachment_descriptor: vk.DescriptorImageInfo = .{
-                .image_layout = .read_only_optimal,
+                .image_layout = .shader_read_only_optimal,
                 .image_view = self.depth_buffer_image_view[i],
                 .sampler = .null_handle,
             };
 
             // Depth attachment descriptor write
             const depth_write: vk.WriteDescriptorSet = .{
-                .dst_set = self.input_descriptor_sets.items[i],
+                .dst_set = self.input_descriptor_sets[i],
                 .dst_binding = 1,
                 .dst_array_element = 0,
                 .descriptor_type = .input_attachment,
                 .descriptor_count = 1,
                 .p_image_info = @ptrCast(&depth_attachment_descriptor),
+                .p_buffer_info = undefined,
+                .p_texel_buffer_view = undefined,
             };
 
             // List of input descriptor set writes
@@ -1424,7 +1441,8 @@ pub const VulkanRenderer = struct {
         };
 
         const clear_values = [_]vk.ClearValue{
-            .{ .color = .{ .float_32 = [4]f32{ 0.6, 0.65, 0.4, 1.0 } } },
+            .{ .color = .{ .float_32 = .{ 0.0, 0.0, 0.0, 0.0 } } },
+            .{ .color = .{ .float_32 = .{ 0.6, 0.65, 0.4, 1.0 } } },
             .{ .depth_stencil = .{ .depth = 1.0, .stencil = 1 } },
         };
 
@@ -1498,6 +1516,21 @@ pub const VulkanRenderer = struct {
                 }
             }
 
+            // Start second subpass
+            command_buffer.nextSubpass(.@"inline");
+
+            command_buffer.bindPipeline(.graphics, self.second_pipeline);
+            command_buffer.bindDescriptorSets(
+                .graphics,
+                self.second_pipeline_layout,
+                0,
+                1,
+                @ptrCast(&self.input_descriptor_sets[current_image]),
+                0,
+                null,
+            );
+            command_buffer.draw(3, 1, 0, 0);
+
             // End render pass
             command_buffer.endRenderPass();
         }