tiny.wayland.shm

1pub const Buffer = struct {2    object_id: u32,3    mapping: []align(std.heap.page_size_min) u8,4    byte_len: usize,5    width: u32,6    height: u32,7    stride: u32,8    format: Format,9    busy: bool = false,1011    pub fn open(12        client: *runtime.Client,13        shm: u32,14        width: u32,15        height: u32,16        format: Format,17    ) Error!Buffer {18        const dimensions = try Dimensions.init(width, height);19        const descriptor = try createDescriptor();20        var descriptor_owned = true;21        defer if (descriptor_owned) sys.fd.close(descriptor);22        try truncate(descriptor, dimensions.byte_len);2324        const mapping = try mapDescriptor(descriptor, dimensions.byte_len);25        errdefer sys.memory.unmap(mapping);2627        const pool = try createPool(client, shm, descriptor, dimensions.byte_len);28        descriptor_owned = false;29        var pool_live = true;30        defer if (pool_live) destroy(client, pool, core.wl_shm_pool.requests.destroy.opcode);3132        const buffer_id = try createBuffer(33            client,34            pool,35            width,36            height,37            dimensions.stride,38            format,39        );40        errdefer destroy(41            client,42            buffer_id,43            core.wl_buffer.requests.destroy.opcode,44        );45        try closePool(client, pool);46        pool_live = false;4748        return .{49            .object_id = buffer_id,50            .mapping = mapping,51            .byte_len = dimensions.byte_len,52            .width = width,53            .height = height,54            .stride = dimensions.stride,55            .format = format,56        };57    }5859    pub fn deinit(self: *Buffer, client: *runtime.Client) void {60        destroy(client, self.object_id, core.wl_buffer.requests.destroy.opcode);61        sys.memory.unmap(self.mapping);62        self.* = undefined;63    }6465    pub fn dispatch(self: *Buffer, event: *runtime.RoutedView) !void {66        if (event.object_id != self.object_id or67            event.metadata.opcode != core.wl_buffer.events.release.opcode)68        {69            return error.InvalidBufferEvent;70        }71        var decoder = try event.borrowedDecoder();72        try decoder.finish();73        self.busy = false;74    }7576    /// Converts the pixels of the rectangle `region` of the full frame `rgba8`77    /// into the buffer, reordering each pixel's bytes into the buffer's format.78    /// The slice `rgba8` covers the whole buffer at the buffer's extent and79    /// stride, so a rectangle sits at the same byte offset in both. A present80    /// calls this to copy the changed part of a frame into the buffer the81    /// compositor will read. A present of the whole image passes the whole82    /// buffer as the rectangle, and a present of one change passes that83    /// change's rectangle and touches those rows alone. A source shorter than84    /// the buffer fails with `error.DestinationTooSmall`. A rectangle with zero85    /// width or height, or one reaching past the buffer's extent, fails with86    /// `error.InvalidRegion`.87    pub fn writeRgba8(self: *Buffer, rgba8: []const u8, region: Region) PixelError!void {88        if (rgba8.len < self.byte_len) return error.DestinationTooSmall;89        _ = try regionByteLen(self, region);90        std.debug.assert(self.stride == self.width * 4);91        const row_byte_len = @as(usize, region.width) * 4;92        var row: u32 = 0;93        while (row < region.height) : (row += 1) {94            const offset =95                @as(usize, region.y + row) * self.stride +96                @as(usize, region.x) * 4;97            convertToShm(98                self.mapping[offset..][0..row_byte_len],99                rgba8[offset..][0..row_byte_len],100                self.format,101            );102        }103    }104105    /// Returns the rectangle covering the whole buffer, so a caller that sends106    /// the whole image passes this rectangle to `writeRgba8` for a present with107    /// no damage list.108    pub fn fullRegion(self: *const Buffer) Region {109        return .{ .x = 0, .y = 0, .width = self.width, .height = self.height };110    }111112    pub fn copyRegionRgba8(113        self: *const Buffer,114        region: Region,115        destination: []u8,116    ) PixelError!void {117        const byte_len = try regionByteLen(self, region);118        if (destination.len < byte_len) return error.DestinationTooSmall;119        var row: u32 = 0;120        while (row < region.height) : (row += 1) {121            const source_offset =122                @as(usize, region.y + row) * self.stride +123                @as(usize, region.x) * 4;124            const destination_offset = @as(usize, row) * region.width * 4;125            const row_byte_len = @as(usize, region.width) * 4;126            convertFromShm(127                destination[destination_offset..][0..row_byte_len],128                self.mapping[source_offset..][0..row_byte_len],129                self.format,130            );131        }132    }133};

1pub const Error = error{2    OutOfMemory,3    DimensionsTooLarge,4    CreateFailed,5};

1pub const Format = enum(u32) {2    argb8888 = 0,3    xrgb8888 = 1,4    abgr8888 = 0x3432_4241,5    xbgr8888 = 0x3432_4258,67    pub fn fromRaw(raw: u32) ?Format {8        return std.enums.fromInt(Format, raw);9    }10};

1pub const PixelError = error{2    InvalidRegion,3    DestinationTooSmall,4};

1pub const Region = struct {2    x: u32,3    y: u32,4    width: u32,5    height: u32,6};

1pub const shm = @import("shm/root.zig");

1const buffer = @import("buffer.zig");23pub const Buffer = buffer.Buffer;4pub const Error = buffer.Error;5pub const Format = buffer.Format;6pub const PixelError = buffer.PixelError;7pub const Region = buffer.Region;