feat(gpu): adding linux-drm

Author: RossComputerGuy

build.zig

@@ -30,6 +30,15 @@ pub fn build(b: *std.Build) void {
         },
     });
 
+    if (target.result.os.tag == .linux) {
+        const libdrm = b.dependency("libdrm", .{
+            .target = target,
+            .optimize = optimize,
+        });
+
+        module.addImport("libdrm", libdrm.module("libdrm"));
+    }
+
     const autodoc_test = b.addObject(.{
         .name = "phantom",
         .root_module = module,

build.zig.zon

@@ -15,6 +15,10 @@
             .url = "https://codeberg.org/ifreund/zig-wayland/archive/f3c5d503e540ada8cbcb056420de240af0c094f7.tar.gz",
             .hash = "wayland-0.4.0-dev-lQa1kjfIAQCmhhQu3xF0KH-94-TzeMXOqfnP0-Dg6Wyy",
         },
+        .libdrm = .{
+            .url = "https://github.com/MidstallSoftware/libdrm.zig/archive/d020314c5fcd78d64bdeecda3a42d0e43522f9af.tar.gz",
+            .hash = "libdrm-0.1.0-iX14LQFJAQAEHpJCxO9os_WFkU-GVD1kuLKkWnGqQRxz",
+        },
     },
     .fingerprint = 0x6896f6aeaa10b7f9,
 }

lib/phantom/gpu.zig

@@ -1,9 +1,12 @@
+pub const backend = @import("gpu/backend.zig");
+
 pub const Connector = @import("gpu/Connector.zig");
 pub const Device = @import("gpu/Device.zig");
 pub const Provider = @import("gpu/Provider.zig");
 pub const Texture = @import("gpu/Texture.zig");
 
 test {
+    _ = backend;
     _ = Connector;
     _ = Device;
     _ = Provider;

lib/phantom/gpu/Device.zig

@@ -3,14 +3,14 @@ const Connector = @import("Connector.zig");
 const Self = @This();
 
 pub const VTable = struct {
-    getConnectors: *const fn (*anyopaque) anyerror![]*Connector,
+    getConnectors: *const fn (*anyopaque) anyerror![]const *Connector,
     destroy: *const fn (*anyopaque) void,
 };
 
 ptr: *anyopaque,
 vtable: *const VTable,
 
-pub inline fn getConnectors(self: *Self) anyerror![]*Connector {
+pub inline fn getConnectors(self: *Self) anyerror![]const *Connector {
     return self.vtable.getConnectors(self.ptr);
 }
 

lib/phantom/gpu/backend.zig

@@ -0,0 +1,9 @@
+const builtin = @import("builtin");
+
+pub const linux_drm = @import("backend/linux_drm.zig");
+
+test {
+    if (builtin.os.tag == .linux) {
+        _ = linux_drm;
+    }
+}

lib/phantom/gpu/backend/linux_drm.zig

@@ -0,0 +1,11 @@
+//! GPU backend for Linux using the Direct Rendering Manager subsystem.
+
+pub const Connector = @import("linux_drm/Connector.zig");
+pub const Device = @import("linux_drm/Device.zig");
+pub const Provider = @import("linux_drm/Provider.zig");
+
+test {
+    _ = Connector;
+    _ = Device;
+    _ = Provider;
+}

lib/phantom/gpu/backend/linux_drm/Connector.zig

@@ -0,0 +1,58 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const libdrm = @import("libdrm");
+const Connector = @import("../../Connector.zig");
+const Device = @import("../../Device.zig");
+const Self = @This();
+
+allocator: Allocator,
+node: libdrm.Node,
+base: Device,
+
+pub fn create(alloc: Allocator, node: libdrm.Node) !*Device {
+    const self = try alloc.create(Self);
+    errdefer alloc.destroy(self);
+
+    self.* = .{
+        .allocator = alloc,
+        .node = node,
+        .base = .{
+            .ptr = self,
+            .vtable = &.{
+                .getConnectors = impl_getConnectors,
+                .destroy = impl_destroy,
+            },
+        },
+    };
+    return &self.base;
+}
+
+pub fn getConnectors(self: *Self) ![]const *Connector {
+    var list = std.ArrayList(*Connector).init(self.allocator);
+    defer list.deinit();
+
+    const modeCardRes = try self.node.getModeCardRes();
+    defer modeCardRes.deinit(self.allocator);
+
+    if (modeCardRes.connectorIds()) |connectorIds| {
+        for (connectorIds) |connectorId| {
+            std.debug.print("{}\n", .{connectorId});
+        }
+    }
+    return try list.toOwnedSlice();
+}
+
+pub fn destroy(self: *Self) void {
+    self.node.deinit();
+    self.allocator.destroy(self);
+}
+
+fn impl_getConnectors(ptr: *anyopaque) anyerror![]const *Connector {
+    const self: *Self = @alignCast(@ptrCast(ptr));
+    return self.getConnectors();
+}
+
+fn impl_destroy(ptr: *anyopaque) void {
+    const self: *Self = @alignCast(@ptrCast(ptr));
+    return self.destroy();
+}

lib/phantom/gpu/backend/linux_drm/Device.zig

@@ -0,0 +1,81 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const libdrm = @import("libdrm");
+const Provider = @import("../../Provider.zig");
+const Device = @import("../../Device.zig");
+const LinuxDrmDevice = @import("Device.zig");
+const Self = @This();
+
+allocator: Allocator,
+base: Provider,
+
+pub fn create(alloc: Allocator) !*Provider {
+    const self = try alloc.create(Self);
+    errdefer alloc.destroy(self);
+
+    self.* = .{
+        .allocator = alloc,
+        .base = .{
+            .ptr = self,
+            .vtable = &.{
+                .getDevices = impl_getDevices,
+                .destroy = impl_destroy,
+            },
+        },
+    };
+    return &self.base;
+}
+
+pub fn getDevices(self: *Self) anyerror![]const *Device {
+    var list = std.ArrayList(*Device).init(self.allocator);
+    defer list.deinit();
+
+    var iter = libdrm.Node.Iterator.init(self.allocator, .primary);
+    while (iter.next()) |node| {
+        const device = try LinuxDrmDevice.create(self.allocator, node);
+        errdefer device.destroy();
+
+        try list.append(device);
+    }
+
+    return try list.toOwnedSlice();
+}
+
+pub fn destroy(self: *Self) void {
+    self.allocator.destroy(self);
+}
+
+fn impl_getDevices(ptr: *anyopaque) anyerror![]const *Device {
+    const self: *Self = @alignCast(@ptrCast(ptr));
+    return self.getDevices();
+}
+
+fn impl_destroy(ptr: *anyopaque) void {
+    const self: *Self = @alignCast(@ptrCast(ptr));
+    return self.destroy();
+}
+
+test {
+    const provider = try create(std.testing.allocator);
+    defer provider.destroy();
+
+    const devices = try provider.getDevices();
+    defer {
+        for (devices) |dev| dev.destroy();
+        std.testing.allocator.free(devices);
+    }
+
+    if (devices.len == 0) return error.SkipZigTest;
+
+    std.debug.print("{any}\n", .{devices});
+
+    for (devices) |dev| {
+        const connectors = dev.getConnectors() catch continue;
+        defer {
+            for (connectors) |conn| conn.destroy();
+            std.testing.allocator.free(connectors);
+        }
+
+        std.debug.print("{any}\n", .{connectors});
+    }
+}