improving renderpasses support

src/software/SoftCommandBuffer.zig

@@ -33,6 +33,38 @@ interface: Interface,
 command_allocator: std.heap.ArenaAllocator,
 commands: std.ArrayList(Command),
 
+fn attachmentIsReferencedBySubpass(render_pass: *SoftRenderPass, attachment_index: u32) bool {
+    for (render_pass.interface.subpasses) |subpass| {
+        if (subpass.input_attachments) |attachments| {
+            for (attachments) |attachment| {
+                if (attachment.attachment == attachment_index)
+                    return true;
+            }
+        }
+
+        if (subpass.color_attachments) |attachments| {
+            for (attachments) |attachment| {
+                if (attachment.attachment == attachment_index)
+                    return true;
+            }
+        }
+
+        if (subpass.resolve_attachments) |attachments| {
+            for (attachments) |attachment| {
+                if (attachment.attachment == attachment_index)
+                    return true;
+            }
+        }
+
+        if (subpass.depth_stencil_attachments) |attachment| {
+            if (attachment.attachment == attachment_index)
+                return true;
+        }
+    }
+
+    return false;
+}
+
 pub fn create(device: *base.Device, allocator: std.mem.Allocator, info: *const vk.CommandBufferAllocateInfo) VkError!*Self {
     const self = allocator.create(Self) catch return VkError.OutOfHostMemory;
     errdefer allocator.destroy(self);
@@ -267,9 +299,13 @@ pub fn beginRenderPass(interface: *Interface, render_pass: *base.RenderPass, fra
             const impl: *Impl = @ptrCast(@alignCast(context));
             device.renderer.render_pass = impl.render_pass;
             device.renderer.framebuffer = impl.framebuffer;
+            device.renderer.render_area = impl.render_area;
             device.renderer.subpass_index = 0;
 
             for (impl.render_pass.interface.attachments, impl.framebuffer.interface.attachments, 0..) |desc, attachment, index| {
+                if (!attachmentIsReferencedBySubpass(impl.render_pass, @intCast(index)))
+                    continue;
+
                 const image: *SoftImage = @alignCast(@fieldParentPtr("interface", attachment.image));
                 var clear_mask: vk.ImageAspectFlags = .{};
 
@@ -987,6 +1023,7 @@ pub fn endRenderPass(interface: *Interface) VkError!void {
 
             device.renderer.render_pass = null;
             device.renderer.framebuffer = null;
+            device.renderer.render_area = null;
         }
     };
 

src/software/SoftPipeline.zig

@@ -303,6 +303,14 @@ fn imageMipLevel(image_view: *SoftImageView, lod: ?i32) u32 {
     return range.base_mip_level + @min(mip_lod, max_lod);
 }
 
+fn imageReadAspect(image_view: *SoftImageView, comptime int_read: bool) vk.ImageAspectFlags {
+    const aspect = image_view.interface.subresource_range.aspect_mask;
+    if (aspect.depth_bit and aspect.stencil_bit) {
+        return if (int_read) .{ .stencil_bit = true } else .{ .depth_bit = true };
+    }
+    return aspect;
+}
+
 fn subpassDataCoord(x: i32, y: i32, z: i32) SpvRuntimeError!vk.Offset3D {
     const coord = current_fragment_coord orelse return SpvRuntimeError.Unknown;
     return .{ .x = coord.x + x, .y = coord.y + y, .z = coord.z + z };
@@ -331,14 +339,15 @@ fn readImageFloat4(context: *anyopaque, dim: spv.SpvDim, x: i32, y: i32, z: i32,
             .cube => cube_face,
             else => 0,
         };
+        const aspect_mask = imageReadAspect(image_view, false);
         pixel = SoftSampler.swizzleFloat4(image.readFloat4(
             image_coord,
             .{
-                .aspect_mask = image_view.interface.subresource_range.aspect_mask,
+                .aspect_mask = aspect_mask,
                 .mip_level = mip_level,
                 .array_layer = array_layer,
             },
-            image_view.interface.format,
+            base.format.fromAspect(image_view.interface.format, aspect_mask),
         ) catch return SpvRuntimeError.Unknown, image_view.interface.components);
     }
     return .{
@@ -372,14 +381,15 @@ fn readImageInt4(context: *anyopaque, dim: spv.SpvDim, x: i32, y: i32, z: i32, l
             .cube => cube_face,
             else => 0,
         };
+        const aspect_mask = imageReadAspect(image_view, true);
         pixel = SoftSampler.swizzleInt4(image.readInt4(
             image_coord,
             .{
-                .aspect_mask = image_view.interface.subresource_range.aspect_mask,
+                .aspect_mask = aspect_mask,
                 .mip_level = mip_level,
                 .array_layer = array_layer,
             },
-            image_view.interface.format,
+            base.format.fromAspect(image_view.interface.format, aspect_mask),
         ) catch return SpvRuntimeError.Unknown, image_view.interface.components);
     }
     return .{

src/software/device/Renderer.zig

@@ -135,6 +135,7 @@ state: *PipelineState,
 
 render_pass: ?*SoftRenderPass,
 framebuffer: ?*SoftFramebuffer,
+render_area: ?vk.Rect2D,
 dynamic_state: DynamicState,
 
 subpass_index: usize,
@@ -146,6 +147,7 @@ pub fn init(device: *SoftDevice, state: *PipelineState, active_occlusion_queries
         .state = state,
         .render_pass = null,
         .framebuffer = null,
+        .render_area = null,
         .dynamic_state = .{
             .viewports = null,
             .scissor = null,

src/software/device/fragment.zig

@@ -16,6 +16,7 @@ const INTERFACE_BLOB_PADDING = @sizeOf(zm.F32x4);
 pub const InvocationResult = struct {
     outputs: [spv.SPIRV_MAX_OUTPUT_LOCATIONS][@sizeOf(zm.F32x4)]u8,
     depth: ?f32,
+    sample_mask: ?vk.SampleMask,
 };
 
 pub const DerivativeInputs = struct {
@@ -76,7 +77,7 @@ pub fn shaderInvocation(
     SoftPipeline.current_fragment_coord = .{
         .x = @intFromFloat(position[0]),
         .y = @intFromFloat(position[1]),
-        .z = @intFromFloat(position[2]),
+        .z = 0,
     };
     defer SoftPipeline.current_fragment_coord = previous_fragment_coord;
 
@@ -165,6 +166,15 @@ pub fn shaderInvocation(
         else => return err,
     }
 
+    var sample_mask: ?vk.SampleMask = null;
+    var frag_sample_mask: [1]vk.SampleMask = undefined;
+    if (rt.readBuiltIn(std.mem.asBytes(&frag_sample_mask), .SampleMask)) {
+        sample_mask = frag_sample_mask[0];
+    } else |err| switch (err) {
+        SpvRuntimeError.InvalidSpirV, SpvRuntimeError.NotFound => {},
+        else => return err,
+    }
+
     try rt.flushDescriptorSets(allocator);
     freeOwnedInputs(allocator, fragment_inputs);
     if (derivatives) |owned_derivatives| {
@@ -175,6 +185,7 @@ pub fn shaderInvocation(
     return .{
         .outputs = outputs,
         .depth = depth,
+        .sample_mask = sample_mask,
     };
 }
 

src/software/device/rasterizer.zig

@@ -63,6 +63,8 @@ pub fn processThenFragmentStage(renderer: *Renderer, allocator: std.mem.Allocato
             .base = try render_target.mapAsSliceWithAddedOffset(u8, color_attachment_subresource_offset, color_attachment_subresource_size),
             .row_pitch = render_target.getRowPitchMemSizeForMipLevelWithFormat(color_range.aspect_mask, color_range.base_mip_level, color_format),
             .texel_size = base.format.texelSize(color_format),
+            .sample_count = render_target.interface.samples.toInt(),
+            .sample_stride = render_target.getMipLevelSize(color_range.aspect_mask, color_range.base_mip_level),
             .width = color_extent.width,
             .height = color_extent.height,
             .format = color_format,
@@ -96,6 +98,8 @@ pub fn processThenFragmentStage(renderer: *Renderer, allocator: std.mem.Allocato
             .base = try depth_attachment.?.mapAsSliceWithAddedOffset(u8, attachment_subresource_offset, attachment_subresource_size),
             .row_pitch = depth_attachment.?.getRowPitchMemSizeForMipLevelWithFormat(depth_aspect, depth_range.base_mip_level, depth_format),
             .texel_size = base.format.texelSize(depth_aspect_format),
+            .sample_count = depth_attachment.?.interface.samples.toInt(),
+            .sample_stride = depth_attachment.?.getMipLevelSize(depth_aspect, depth_range.base_mip_level),
             .width = depth_extent.width,
             .height = depth_extent.height,
             .format = depth_aspect_format,
@@ -126,6 +130,8 @@ pub fn processThenFragmentStage(renderer: *Renderer, allocator: std.mem.Allocato
             .base = try depth_attachment.?.mapAsSliceWithAddedOffset(u8, attachment_subresource_offset, attachment_subresource_size),
             .row_pitch = depth_attachment.?.getRowPitchMemSizeForMipLevelWithFormat(stencil_aspect, stencil_range.base_mip_level, stencil_format),
             .texel_size = base.format.texelSize(stencil_aspect_format),
+            .sample_count = depth_attachment.?.interface.samples.toInt(),
+            .sample_stride = depth_attachment.?.getMipLevelSize(stencil_aspect, stencil_range.base_mip_level),
             .width = stencil_extent.width,
             .height = stencil_extent.height,
             .format = stencil_aspect_format,
@@ -355,6 +361,7 @@ fn clipTransformAndRasterizePoint(
             var fragment_result: fragment.InvocationResult = .{
                 .outputs = std.mem.zeroes([spv.SPIRV_MAX_OUTPUT_LOCATIONS][@sizeOf(zm.F32x4)]u8),
                 .depth = null,
+                .sample_mask = null,
             };
             if (has_fragment_shader) {
                 const frag_x = @as(f32, @floatFromInt(px)) + 0.5;
@@ -387,7 +394,7 @@ fn clipTransformAndRasterizePoint(
                 };
             }
 
-            try common.writeToTargets(fragment_result.outputs, draw_call, color_attachment_access, depth_attachment_access, stencil_attachment_access, true, @intCast(px), @intCast(py), fragment_result.depth orelse transformed.position[2]);
+            try common.writeToTargets(fragment_result.outputs, draw_call, color_attachment_access, depth_attachment_access, stencil_attachment_access, true, @intCast(px), @intCast(py), fragment_result.depth orelse transformed.position[2], fragment_result.sample_mask);
         }
     }
 }

src/software/device/rasterizer/bresenham.zig

@@ -156,6 +156,7 @@ inline fn run(data: RunData) !void {
         var fragment_result: fragment.InvocationResult = .{
             .outputs = std.mem.zeroes([spv.SPIRV_MAX_OUTPUT_LOCATIONS][@sizeOf(F32x4)]u8),
             .depth = null,
+            .sample_mask = null,
         };
         if (data.has_fragment_shader) {
             fragment_result = fragment.shaderInvocation(
@@ -192,6 +193,7 @@ inline fn run(data: RunData) !void {
             @intCast(pixel_x),
             @intCast(pixel_y),
             fragment_result.depth orelse z,
+            fragment_result.sample_mask,
         );
     }
 }

src/software/device/rasterizer/common.zig

@@ -16,6 +16,8 @@ pub const RenderTargetAccess = struct {
     base: []u8,
     row_pitch: usize,
     texel_size: usize,
+    sample_count: usize,
+    sample_stride: usize,
     width: u32,
     height: u32,
     format: vk.Format,
@@ -45,6 +47,22 @@ pub fn scissorContainsPixel(scissor: vk.Rect2D, x: i32, y: i32) bool {
         pixel_y < max_y;
 }
 
+pub fn rectContainsPixel(rect: vk.Rect2D, x: usize, y: usize) bool {
+    const min_x: i64 = @as(i64, rect.offset.x);
+    const min_y: i64 = @as(i64, rect.offset.y);
+
+    const max_x: i64 = min_x + @as(i64, @intCast(rect.extent.width));
+    const max_y: i64 = min_y + @as(i64, @intCast(rect.extent.height));
+
+    const pixel_x: i64 = @intCast(x);
+    const pixel_y: i64 = @intCast(y);
+
+    return pixel_x >= min_x and
+        pixel_x < max_x and
+        pixel_y >= min_y and
+        pixel_y < max_y;
+}
+
 pub fn targetContainsPixel(target: RenderTargetAccess, x: i32, y: i32) bool {
     if (x < 0 or y < 0)
         return false;
@@ -62,6 +80,14 @@ pub fn targetOffset(target: RenderTargetAccess, x: usize, y: usize) ?usize {
     return offset;
 }
 
+pub fn targetSampleOffset(target: RenderTargetAccess, x: usize, y: usize, sample_index: usize) ?usize {
+    const base_offset = targetOffset(target, x, y) orelse return null;
+    const offset = base_offset + sample_index * target.sample_stride;
+    if (offset > target.base.len or target.texel_size > target.base.len - offset)
+        return null;
+    return offset;
+}
+
 pub fn compare(comptime T: type, op: vk.CompareOp, reference: T, value: T) bool {
     return switch (op) {
         .never => false,
@@ -100,6 +126,10 @@ fn updateStencilValue(stencil: *RenderTargetAccess, offset: usize, state: vk.Ste
 
 pub fn stencilTestAndUpdate(stencil: *RenderTargetAccess, x: usize, y: usize, state: vk.StencilOpState, depth_passed: ?bool) bool {
     const offset = targetOffset(stencil.*, x, y) orelse return false;
+    return stencilTestAndUpdateAtOffset(stencil, offset, state, depth_passed);
+}
+
+fn stencilTestAndUpdateAtOffset(stencil: *RenderTargetAccess, offset: usize, state: vk.StencilOpState, depth_passed: ?bool) bool {
     const current = blitter.readInt4(stencil.base[offset..], stencil.format)[0] & std.math.maxInt(u8);
     const reference = state.reference & std.math.maxInt(u8);
     const compare_mask = state.compare_mask & std.math.maxInt(u8);
@@ -138,10 +168,14 @@ fn quantizeDepthForFormat(format: vk.Format, z: f32) f32 {
 }
 
 pub fn depthTestAndUpdate(depth: *RenderTargetAccess, x: usize, y: usize, z: f32, state: vk.PipelineDepthStencilStateCreateInfo) bool {
+    const offset = targetOffset(depth.*, x, y) orelse return false;
+    return depthTestAndUpdateAtOffset(depth, offset, z, state);
+}
+
+fn depthTestAndUpdateAtOffset(depth: *RenderTargetAccess, offset: usize, z: f32, state: vk.PipelineDepthStencilStateCreateInfo) bool {
     if (state.depth_test_enable == .false)
         return true;
 
-    const offset = targetOffset(depth.*, x, y) orelse return false;
     const reference = quantizeDepthForFormat(depth.format, z);
     const depth_value = blitter.readFloat4(depth.base[offset..], depth.format);
     const passed = compare(f32, state.depth_compare_op, reference, depth_value[0]);
@@ -373,86 +407,148 @@ pub fn writeToTargets(
     x: usize,
     y: usize,
     z: f32,
+    fragment_sample_mask: ?vk.SampleMask,
 ) VkError!void {
     const io = draw_call.renderer.device.interface.io();
-    const depth_stencil_state = draw_call.renderer.state.pipeline.?.interface.mode.graphics.depth_stencil;
+    const pipeline_data = draw_call.renderer.state.pipeline.?.interface.mode.graphics;
+    const depth_stencil_state = pipeline_data.depth_stencil;
+
+    if (!sampleMaskEnablesAnySample(pipeline_data.multisample, fragment_sample_mask))
+        return;
 
     if (x >= draw_call.framebuffer.interface.width or y >= draw_call.framebuffer.interface.height)
         return;
 
-    var stencil_state: ?vk.StencilOpState = null;
+    if (draw_call.renderer.render_area) |render_area| {
-    var stencil_offset: ?usize = null;
+        if (!rectContainsPixel(render_area, x, y))
-    if (stencil_attachment_access) |stencil| {
+            return;
-        if (depth_stencil_state) |state| {
+    }
-            if (state.stencil_test_enable == .true) {
+
-                stencil_state = if (front_face)
+    const sample_count = pipeline_data.multisample.rasterization_samples.toInt();
-                    resolveStencilState(draw_call, state.front, true)
+    for (0..sample_count) |sample_index| {
-                else
+        if (!sampleMaskEnablesSample(pipeline_data.multisample, fragment_sample_mask, sample_index))
-                    resolveStencilState(draw_call, state.back, false);
+            continue;
-                stencil_offset = targetOffset(stencil.*, x, y) orelse return;
+
-                if (!stencilTest(stencil, stencil_offset.?, stencil_state.?)) {
+        var stencil_state: ?vk.StencilOpState = null;
-                    updateStencilValue(stencil, stencil_offset.?, stencil_state.?, stencil_state.?.fail_op);
+        var stencil_offset: ?usize = null;
-                    return;
+        if (stencil_attachment_access) |stencil| {
+            if (depth_stencil_state) |state| {
+                if (state.stencil_test_enable == .true) {
+                    stencil_state = if (front_face)
+                        resolveStencilState(draw_call, state.front, true)
+                    else
+                        resolveStencilState(draw_call, state.back, false);
+                    stencil_offset = targetSampleOffset(stencil.*, x, y, sample_index) orelse continue;
+                    if (!stencilTest(stencil, stencil_offset.?, stencil_state.?)) {
+                        updateStencilValue(stencil, stencil_offset.?, stencil_state.?, stencil_state.?.fail_op);
+                        continue;
+                    }
                 }
             }
         }
-    }
 
-    // After work depth test to avoid overwritten depth pixels during fragment invocations.
+        // After work depth test to avoid overwritten depth pixels during fragment invocations.
-    var depth_passed: ?bool = null;
+        var depth_passed: ?bool = null;
-    if (depth_attachment_access) |depth| {
+        if (depth_attachment_access) |depth| {
-        const depth_offset = targetOffset(depth.*, x, y) orelse return;
+            const depth_offset = targetSampleOffset(depth.*, x, y, sample_index) orelse continue;
 
-        depth.mutex.lock(io) catch return VkError.DeviceLost;
+            depth.mutex.lock(io) catch return VkError.DeviceLost;
-        defer depth.mutex.unlock(io);
+            defer depth.mutex.unlock(io);
 
-        if (depth_stencil_state) |state| {
+            if (depth_stencil_state) |state| {
-            depth_passed = depthTestAndUpdate(depth, x, y, z, state);
+                depth_passed = depthTestAndUpdateAtOffset(depth, depth_offset, z, state);
-            if (!depth_passed.? and stencil_state == null)
+                if (!depth_passed.? and stencil_state == null)
-                return;
+                    continue;
-        } else {
+            } else {
-            const depth_value = blitter.readFloat4(depth.base[depth_offset..], depth.format);
+                const depth_value = blitter.readFloat4(depth.base[depth_offset..], depth.format);
-            if (z >= depth_value[0])
+                if (z >= depth_value[0])
-                return;
+                    continue;
-            blitter.writeFloat4(zm.f32x4s(z), depth.base[depth_offset..], depth.format);
+                blitter.writeFloat4(zm.f32x4s(z), depth.base[depth_offset..], depth.format);
-            depth_passed = true;
+                depth_passed = true;
-        }
-    }
-
-    if (stencil_attachment_access) |stencil| {
-        if (stencil_state) |state| {
-            if (depth_passed != null and !depth_passed.?) {
-                updateStencilValue(stencil, stencil_offset.?, state, state.depth_fail_op);
-                return;
             }
-            updateStencilValue(stencil, stencil_offset.?, state, state.pass_op);
         }
-    }
 
-    for (draw_call.renderer.active_occlusion_queries.items) |active| {
+        if (stencil_attachment_access) |stencil| {
-        try active.pool.addSamples(active.query, 1);
+            if (stencil_state) |state| {
-    }
+                if (depth_passed != null and !depth_passed.?) {
+                    updateStencilValue(stencil, stencil_offset.?, state, state.depth_fail_op);
+                    continue;
+                }
+                updateStencilValue(stencil, stencil_offset.?, state, state.pass_op);
+            }
+        }
 
-    for (color_attachment_access, 0..) |maybe_color, location| {
+        for (draw_call.renderer.active_occlusion_queries.items) |active| {
-        const color = maybe_color orelse continue;
+            try active.pool.addSamples(active.query, 1);
-        const color_offset = targetOffset(color, x, y) orelse continue;
+        }
 
-        if (base.format.isUnnormalizedInteger(color.format)) {
+        for (color_attachment_access, 0..) |maybe_color, location| {
-            blitter.writeInt4(std.mem.bytesToValue(U32x4, &outputs[location]), color.base[color_offset..], color.format);
+            const color = maybe_color orelse continue;
-        } else {
+            const color_offset = targetSampleOffset(color, x, y, sample_index) orelse continue;
-            const pipeline_data = draw_call.renderer.state.pipeline.?.interface.mode.graphics;
+            if (base.format.isUnnormalizedInteger(color.format)) {
-            const src = fragmentOutputFloat4(outputs[location], color.format);
+                blitter.writeInt4(std.mem.bytesToValue(U32x4, &outputs[location]), color.base[color_offset..], color.format);
-            const encoded_dst = blitter.readFloat4(color.base[color_offset..], color.format);
+            } else {
-            const dst = if (base.format.isSrgb(color.format)) zm.srgbToRgb(encoded_dst) else encoded_dst;
+                const src = fragmentOutputFloat4(outputs[location], color.format);
-            const final_color = if (pipeline_data.color_blend.attachments) |attachments| blk: {
+                const encoded_dst = blitter.readFloat4(color.base[color_offset..], color.format);
-                if (location >= attachments.len)
+                const dst = if (base.format.isSrgb(color.format)) zm.srgbToRgb(encoded_dst) else encoded_dst;
-                    break :blk src;
+                const final_color = if (pipeline_data.color_blend.attachments) |attachments| blk: {
-                const constants = draw_call.renderer.dynamic_state.blend_constants orelse pipeline_data.color_blend.constants;
+                    if (location >= attachments.len)
-                const blended = blendColor(src, dst, attachments[location], constants, color.format);
+                        break :blk src;
-                break :blk applyColorWriteMask(blended, dst, attachments[location].color_write_mask);
+                    const constants = draw_call.renderer.dynamic_state.blend_constants orelse pipeline_data.color_blend.constants;
-            } else src;
+                    const blended = blendColor(src, dst, attachments[location], constants, color.format);
-            const encoded_color = if (base.format.isSrgb(color.format)) zm.rgbToSrgb(final_color) else final_color;
+                    break :blk applyColorWriteMask(blended, dst, attachments[location].color_write_mask);
-            blitter.writeFloat4(encoded_color, color.base[color_offset..], color.format);
+                } else src;
+                const encoded_color = if (base.format.isSrgb(color.format)) zm.rgbToSrgb(final_color) else final_color;
+                blitter.writeFloat4(encoded_color, color.base[color_offset..], color.format);
+            }
         }
     }
 }
+
+fn sampleMaskEnablesAnySample(multisample: anytype, fragment_sample_mask: ?vk.SampleMask) bool {
+    const sample_count = multisample.rasterization_samples.toInt();
+    if (multisample.sample_mask == null and fragment_sample_mask == null)
+        return true;
+
+    if (multisample.sample_mask) |pipeline_sample_mask| {
+        for (pipeline_sample_mask, 0..) |word, word_index| {
+            if (sampleMaskWordEnablesAnySample(sample_count, word_index, word, fragment_sample_mask))
+                return true;
+        }
+        return false;
+    }
+
+    return sampleMaskWordEnablesAnySample(sample_count, 0, std.math.maxInt(vk.SampleMask), fragment_sample_mask);
+}
+
+fn sampleMaskWordEnablesAnySample(sample_count: usize, word_index: usize, pipeline_word: vk.SampleMask, fragment_sample_mask: ?vk.SampleMask) bool {
+    const remaining_samples = sample_count -| (word_index * 32);
+    const active_bits = @min(remaining_samples, 32);
+    if (active_bits == 0)
+        return false;
+
+    const active_mask: vk.SampleMask = if (active_bits == 32)
+        std.math.maxInt(vk.SampleMask)
+    else
+        (@as(vk.SampleMask, 1) << @intCast(active_bits)) - 1;
+
+    const fragment_word = if (word_index == 0) fragment_sample_mask orelse std.math.maxInt(vk.SampleMask) else std.math.maxInt(vk.SampleMask);
+    return ((pipeline_word & fragment_word) & active_mask) != 0;
+}
+
+fn sampleMaskEnablesSample(multisample: anytype, fragment_sample_mask: ?vk.SampleMask, sample_index: usize) bool {
+    if (sample_index >= multisample.rasterization_samples.toInt())
+        return false;
+
+    const word_index = sample_index / 32;
+    const bit_index: u5 = @intCast(sample_index % 32);
+    const bit = @as(vk.SampleMask, 1) << bit_index;
+
+    const pipeline_word = if (multisample.sample_mask) |pipeline_sample_mask|
+        if (word_index < pipeline_sample_mask.len) pipeline_sample_mask[word_index] else @as(vk.SampleMask, 0)
+    else
+        std.math.maxInt(vk.SampleMask);
+
+    const fragment_word = if (word_index == 0) fragment_sample_mask orelse std.math.maxInt(vk.SampleMask) else std.math.maxInt(vk.SampleMask);
+    return (pipeline_word & fragment_word & bit) != 0;
+}

src/software/device/rasterizer/edge_function.zig

@@ -182,6 +182,7 @@ inline fn run(data: RunData) !void {
             var fragment_result: fragment.InvocationResult = .{
                 .outputs = std.mem.zeroes([spv.SPIRV_MAX_OUTPUT_LOCATIONS][@sizeOf(F32x4)]u8),
                 .depth = null,
+                .sample_mask = null,
             };
             if (data.has_fragment_shader) {
                 const inputs = try common.interpolateVertexOutputs(data.allocator, &data.v0, &data.v1, &data.v2, b0, b1, b2);
@@ -251,6 +252,7 @@ inline fn run(data: RunData) !void {
                 @intCast(x),
                 @intCast(y),
                 fragment_result.depth orelse z,
+                fragment_result.sample_mask,
             );
         }
     }

src/vulkan/Pipeline.zig

@@ -50,6 +50,10 @@ mode: union(enum) {
             front_face: vk.FrontFace,
             line_width: f32,
         },
+        multisample: struct {
+            rasterization_samples: vk.SampleCountFlags,
+            sample_mask: ?[]vk.SampleMask,
+        },
         color_blend: struct {
             attachments: ?[]vk.PipelineColorBlendAttachmentState,
             constants: [4]f32,
@@ -106,6 +110,9 @@ pub fn initGraphics(device: *Device, allocator: std.mem.Allocator, cache: ?*Pipe
     var scissors: ?[]vk.Rect2D = null;
     errdefer if (scissors) |value| allocator.free(value);
 
+    var sample_mask: ?[]vk.SampleMask = null;
+    errdefer if (sample_mask) |value| allocator.free(value);
+
     var color_attachments: ?[]vk.PipelineColorBlendAttachmentState = null;
     errdefer if (color_attachments) |value| allocator.free(value);
 
@@ -186,6 +193,24 @@ pub fn initGraphics(device: *Device, allocator: std.mem.Allocator, cache: ?*Pipe
                     .front_face = if (info.p_rasterization_state) |state| state.front_face else return VkError.ValidationFailed,
                     .line_width = if (info.p_rasterization_state) |state| state.line_width else return VkError.ValidationFailed,
                 },
+                .multisample = blk: {
+                    if (rasterizer_discard_enable) {
+                        break :blk .{
+                            .rasterization_samples = .{ .@"1_bit" = true },
+                            .sample_mask = null,
+                        };
+                    }
+
+                    const state = info.p_multisample_state orelse return VkError.ValidationFailed;
+                    const mask_word_count: usize = @divTrunc(state.rasterization_samples.toInt() + 31, 32);
+                    break :blk .{
+                        .rasterization_samples = state.rasterization_samples,
+                        .sample_mask = if (state.p_sample_mask) |mask| blk_mask: {
+                            sample_mask = allocator.dupe(vk.SampleMask, mask[0..mask_word_count]) catch return VkError.OutOfHostMemory;
+                            break :blk_mask sample_mask;
+                        } else null,
+                    };
+                },
                 .color_blend = blk: {
                     if (rasterizer_discard_enable or !has_color_attachments) {
                         break :blk .{
@@ -276,6 +301,9 @@ pub inline fn destroy(self: *Self, allocator: std.mem.Allocator) void {
             if (graphics.viewport_state.scissor) |scissor| {
                 allocator.free(scissor);
             }
+            if (graphics.multisample.sample_mask) |sample_mask| {
+                allocator.free(sample_mask);
+            }
             if (graphics.color_blend.attachments) |attachments| {
                 allocator.free(attachments);
             }

src/vulkan/lib_vulkan.zig

@@ -140,7 +140,6 @@ const device_pfn_map = block: {
         functionMapEntryPoint("vkAcquireNextImage2KHR"),
         functionMapEntryPoint("vkAllocateCommandBuffers"),
         functionMapEntryPoint("vkAllocateDescriptorSets"),
-        functionMapEntryPoint("vkAllocateDescriptorSets"),
         functionMapEntryPoint("vkAllocateMemory"),
         functionMapEntryPoint("vkBeginCommandBuffer"),
         functionMapEntryPoint("vkBindBufferMemory"),