examples: add triangle-msaa

build.zig

@@ -71,6 +71,7 @@ pub fn build(b: *std.build.Builder) void {
 
     inline for ([_]ExampleDefinition{
         .{ .name = "triangle" },
+        .{ .name = "triangle-msaa" },
         .{ .name = "boids" },
         .{ .name = "rotating-cube", .packages = &[_]Pkg{Packages.zmath} },
         .{ .name = "two-cubes", .packages = &[_]Pkg{Packages.zmath} },

examples/triangle-msaa/frag.wgsl

@@ -0,0 +1,3 @@
+@fragment fn main() -> @location(0) vec4<f32> {
+    return vec4<f32>(1.0, 0.0, 0.0, 1.0);
+}

examples/triangle-msaa/main.zig

@@ -0,0 +1,114 @@
+const std = @import("std");
+const mach = @import("mach");
+const gpu = @import("gpu");
+
+pub const App = @This();
+
+pipeline: *gpu.RenderPipeline,
+queue: *gpu.Queue,
+texture: *gpu.Texture,
+texture_view: *gpu.TextureView,
+window_title_timer: mach.Timer,
+
+const sample_count = 4;
+
+pub fn init(app: *App, core: *mach.Core) !void {
+    const vs_module = core.device.createShaderModuleWGSL("vert.wgsl", @embedFile("vert.wgsl"));
+    const fs_module = core.device.createShaderModuleWGSL("frag.wgsl", @embedFile("frag.wgsl"));
+
+    // Fragment state
+    const blend = gpu.BlendState{};
+    const color_target = gpu.ColorTargetState{
+        .format = core.swap_chain_format,
+        .blend = &blend,
+        .write_mask = gpu.ColorWriteMaskFlags.all,
+    };
+    const fragment = gpu.FragmentState.init(.{
+        .module = fs_module,
+        .entry_point = "main",
+        .targets = &.{color_target},
+    });
+    const pipeline_descriptor = gpu.RenderPipeline.Descriptor{
+        .fragment = &fragment,
+        .vertex = gpu.VertexState{
+            .module = vs_module,
+            .entry_point = "main",
+        },
+        .multisample = gpu.MultisampleState{
+            .count = sample_count,
+        },
+    };
+
+    app.pipeline = core.device.createRenderPipeline(&pipeline_descriptor);
+    app.queue = core.device.getQueue();
+
+    app.texture = core.device.createTexture(&gpu.Texture.Descriptor{
+        .size = gpu.Extent3D{
+            .width = core.current_desc.width,
+            .height = core.current_desc.height,
+        },
+        .sample_count = sample_count,
+        .format = core.swap_chain_format,
+        .usage = .{ .render_attachment = true },
+    });
+    app.texture_view = app.texture.createView(null);
+
+    vs_module.release();
+    fs_module.release();
+}
+
+pub fn deinit(app: *App, _: *mach.Core) void {
+    app.texture.release();
+    app.texture_view.release();
+}
+
+pub fn update(app: *App, core: *mach.Core) !void {
+    const back_buffer_view = core.swap_chain.?.getCurrentTextureView();
+    const color_attachment = gpu.RenderPassColorAttachment{
+        .view = app.texture_view,
+        .resolve_target = back_buffer_view,
+        .clear_value = std.mem.zeroes(gpu.Color),
+        .load_op = .clear,
+        .store_op = .discard,
+    };
+
+    const encoder = core.device.createCommandEncoder(null);
+    const render_pass_info = gpu.RenderPassDescriptor.init(.{
+        .color_attachments = &.{color_attachment},
+    });
+    const pass = encoder.beginRenderPass(&render_pass_info);
+    pass.setPipeline(app.pipeline);
+    pass.draw(3, 1, 0, 0);
+    pass.end();
+    pass.release();
+
+    var command = encoder.finish(null);
+    encoder.release();
+
+    app.queue.submit(&.{command});
+    command.release();
+    core.swap_chain.?.present();
+    back_buffer_view.release();
+
+    if (app.window_title_timer.read() >= 1.0) {
+        const window_title = try std.fmt.allocPrintZ(core.allocator, "FPS: {d}", .{@floatToInt(u32, 1 / core.delta_time)});
+        defer core.allocator.free(window_title);
+        try core.internal.window.setTitle(window_title);
+        app.window_title_timer.reset();
+    }
+}
+
+pub fn resize(app: *App, core: *mach.Core, width: u32, height: u32) !void {
+    app.texture.release();
+    app.texture = core.device.createTexture(&gpu.Texture.Descriptor{
+        .size = gpu.Extent3D{
+            .width = width,
+            .height = height,
+        },
+        .sample_count = sample_count,
+        .format = core.swap_chain_format,
+        .usage = .{ .render_attachment = true },
+    });
+    app.texture_view.release();
+    app.texture_view = app.texture.createView(null);
+}

examples/triangle-msaa/vert.wgsl

@@ -0,0 +1,10 @@
+@vertex fn main(
+    @builtin(vertex_index) VertexIndex : u32
+) -> @builtin(position) vec4<f32> {
+    var pos = array<vec2<f32>, 3>(
+        vec2<f32>( 0.0,  0.5),
+        vec2<f32>(-0.5, -0.5),
+        vec2<f32>( 0.5, -0.5)
+    );
+    return vec4<f32>(pos[VertexIndex], 0.0, 1.0);
+}