adding draw indexed

src/soft/device/Device.zig

@@ -25,6 +25,7 @@ pub const PipelineState = struct {
     data: union {
         compute: struct {},
         graphics: struct {
+            index_buffer: Renderer.IndexBuffer,
             vertex_buffers: [lib.MAX_VERTEX_INPUT_BINDINGS]Renderer.VertexBuffer,
         },
     },
@@ -45,6 +46,7 @@ pub fn init(self: *Self, device: *SoftDevice) void {
             .data = switch (i) {
                 GRAPHICS_PIPELINE_STATE => .{
                     .graphics = .{
+                        .index_buffer = undefined,
                         .vertex_buffers = undefined,
                     },
                 },

src/soft/device/Renderer.zig

@@ -32,6 +32,12 @@ pub const VertexBuffer = struct {
     size: usize,
 };
 
+pub const IndexBuffer = struct {
+    buffer: *const SoftBuffer,
+    offset: usize,
+    index_type: vk.IndexType,
+};
+
 pub const DynamicState = struct {
     viewports: ?[]const vk.Viewport,
     scissor: ?[]vk.Rect2D,
@@ -55,6 +61,19 @@ pub const Fragment = struct {
 pub const DrawCall = struct {
     vertices: []Vertex,
     fragments: []Fragment,
+
+    pub fn init(allocator: std.mem.Allocator, vertex_count: usize, instance_count: usize) VkError!@This() {
+        const self: @This() = .{
+            .vertices = allocator.alloc(Vertex, vertex_count * instance_count) catch return VkError.OutOfDeviceMemory,
+            .fragments = undefined,
+        };
+
+        for (self.vertices) |*vertex| {
+            @memset(vertex.outputs[0..], null);
+        }
+
+        return self;
+    }
 };
 
 device: *SoftDevice,
@@ -81,13 +100,12 @@ pub fn init(device: *SoftDevice, state: *PipelineState) Self {
 pub fn draw(self: *Self, vertex_count: usize, instance_count: usize, first_vertex: usize, first_instance: usize) VkError!void {
     const io = self.device.interface.io();
 
-    const render_target_view: *base.ImageView = (self.framebuffer orelse return).interface.attachments[0];
-    const render_target: *SoftImage = @alignCast(@fieldParentPtr("interface", render_target_view.image));
-
     var arena: std.heap.ArenaAllocator = .init(self.device.device_allocator.allocator());
     defer arena.deinit();
     const allocator = arena.allocator();
 
+    var draw_call = try DrawCall.init(allocator, vertex_count, instance_count);
+
     const timer = std.Io.Timestamp.now(io, .real);
     defer if (comptime base.config.logs != .none) {
         const duration = timer.untilNow(io, .real);
@@ -95,58 +113,48 @@ pub fn draw(self: *Self, vertex_count: usize, instance_count: usize, first_verte
         std.log.scoped(.SoftwareRenderer).debug("Drawcall stats:\n>   Took {d}us\n>   Allocated {d} KB", .{ ms, @divTrunc(arena.queryCapacity(), 1000) });
     };
 
-    var draw_call: DrawCall = .{
-        .vertices = allocator.alloc(Vertex, vertex_count * instance_count) catch return VkError.OutOfDeviceMemory,
-        .fragments = undefined,
-    };
-
-    for (draw_call.vertices) |*vertex| {
-        @memset(vertex.outputs[0..], null);
-    }
-
-    self.vertexShaderStage(allocator, &draw_call, vertex_count, instance_count) catch |err| {
+    self.vertexShaderStage(allocator, &draw_call, vertex_count, instance_count, first_vertex, first_instance, null) catch |err| {
         std.log.scoped(.@"Vertex stage").err("catched a '{s}'", .{@errorName(err)});
         if (@errorReturnTrace()) |trace| {
             std.debug.dumpErrorReturnTrace(trace);
         }
     };
 
-    try self.primitiveAssemblyStage(&draw_call);
-    try self.rasterizationStage(allocator, &draw_call);
+    try self.postVertexDraw(allocator, &draw_call);
+}
 
-    self.fragmentShaderStage(&draw_call) catch |err| {
-        std.log.scoped(.@"Fragment stage").err("catched a '{s}'", .{@errorName(err)});
+pub fn drawIndexed(self: *Self, index_count: usize, instance_count: usize, first_index: usize, first_instance: usize, vertex_offset: usize) VkError!void {
+    const io = self.device.interface.io();
+
+    var arena: std.heap.ArenaAllocator = .init(self.device.device_allocator.allocator());
+    defer arena.deinit();
+    const allocator = arena.allocator();
+
+    var draw_call = try DrawCall.init(allocator, index_count, instance_count);
+    const indices = try self.readIndexBuffer(allocator, index_count, first_index, vertex_offset);
+
+    const timer = std.Io.Timestamp.now(io, .real);
+    defer if (comptime base.config.logs != .none) {
+        const duration = timer.untilNow(io, .real);
+        const ms = duration.toMicroseconds();
+        std.log.scoped(.SoftwareRenderer).debug("Drawcall indexed stats:\n>   Took {d}us\n>   Allocated {d} KB", .{ ms, @divTrunc(arena.queryCapacity(), 1000) });
+    };
+
+    self.vertexShaderStage(allocator, &draw_call, index_count, instance_count, 0, first_instance, indices) catch |err| {
+        std.log.scoped(.@"Vertex stage").err("catched a '{s}'", .{@errorName(err)});
         if (@errorReturnTrace()) |trace| {
             std.debug.dumpErrorReturnTrace(trace);
         }
     };
 
-    for (draw_call.fragments) |fragment| {
-        try render_target.writeFloat4(
-            .{
-                .x = @intFromFloat(fragment.position[0]),
-                .y = @intFromFloat(fragment.position[1]),
-                .z = @intFromFloat(fragment.position[2]),
-            },
-            .{
-                .aspect_mask = render_target_view.subresource_range.aspect_mask,
-                .mip_level = render_target_view.subresource_range.base_mip_level,
-                .array_layer = render_target_view.subresource_range.base_array_layer,
-            },
-            render_target_view.format,
-            fragment.color,
-        );
-    }
-
-    _ = first_vertex;
-    _ = first_instance;
+    try self.postVertexDraw(allocator, &draw_call);
 }
 
 pub fn deinit(self: *Self) void {
     _ = self;
 }
 
-fn vertexShaderStage(self: *Self, allocator: std.mem.Allocator, draw_call: *DrawCall, vertex_count: usize, instance_count: usize) !void {
+fn vertexShaderStage(self: *Self, allocator: std.mem.Allocator, draw_call: *DrawCall, vertex_count: usize, instance_count: usize, first_vertex: usize, first_instance: usize, indices: ?[]const u32) !void {
     const pipeline = self.state.pipeline orelse return;
     const batch_size = (pipeline.stages.getPtr(.vertex) orelse return).runtimes.len;
 
@@ -160,6 +168,9 @@ fn vertexShaderStage(self: *Self, allocator: std.mem.Allocator, draw_call: *Draw
                 .batch_id = batch_id,
                 .batch_size = batch_size,
                 .vertex_count = vertex_count,
+                .first_vertex = first_vertex,
+                .first_instance = first_instance,
+                .indices = indices,
                 .instance_index = instance_index,
                 .draw_call = draw_call,
             };
@@ -170,6 +181,38 @@ fn vertexShaderStage(self: *Self, allocator: std.mem.Allocator, draw_call: *Draw
     wg.await(self.device.interface.io()) catch return VkError.DeviceLost;
 }
 
+fn postVertexDraw(self: *Self, allocator: std.mem.Allocator, draw_call: *DrawCall) VkError!void {
+    const render_target_view: *base.ImageView = (self.framebuffer orelse return).interface.attachments[0];
+    const render_target: *SoftImage = @alignCast(@fieldParentPtr("interface", render_target_view.image));
+
+    try self.primitiveAssemblyStage(draw_call);
+    try self.rasterizationStage(allocator, draw_call);
+
+    self.fragmentShaderStage(draw_call) catch |err| {
+        std.log.scoped(.@"Fragment stage").err("catched a '{s}'", .{@errorName(err)});
+        if (@errorReturnTrace()) |trace| {
+            std.debug.dumpErrorReturnTrace(trace);
+        }
+    };
+
+    for (draw_call.fragments) |fragment| {
+        render_target.writeFloat4(
+            .{
+                .x = @intFromFloat(fragment.position[0]),
+                .y = @intFromFloat(fragment.position[1]),
+                .z = 0,
+            },
+            .{
+                .aspect_mask = render_target_view.subresource_range.aspect_mask,
+                .mip_level = render_target_view.subresource_range.base_mip_level,
+                .array_layer = render_target_view.subresource_range.base_array_layer,
+            },
+            render_target_view.format,
+            fragment.color,
+        ) catch {};
+    }
+}
+
 fn primitiveAssemblyStage(self: *Self, draw_call: *DrawCall) VkError!void {
     const viewport = blk: {
         const pipeline_data = &(self.state.pipeline orelse return VkError.InvalidPipelineDrv).interface.mode.graphics;
@@ -251,41 +294,6 @@ fn rasterizationStage(self: *Self, allocator: std.mem.Allocator, draw_call: *Dra
     draw_call.fragments = fragments.toOwnedSlice(allocator) catch return VkError.OutOfDeviceMemory;
 }
 
-fn triangleArea2(v0: *const Vertex, v1: *const Vertex, v2: *const Vertex) f32 {
-    const x0 = v0.position[0];
-    const y0 = v0.position[1];
-    const x1 = v1.position[0];
-    const y1 = v1.position[1];
-    const x2 = v2.position[0];
-    const y2 = v2.position[1];
-
-    return ((x1 - x0) * (y2 - y0)) - ((y1 - y0) * (x2 - x0));
-}
-
-fn triangleIsCulled(self: *Self, v0: *const Vertex, v1: *const Vertex, v2: *const Vertex) VkError!bool {
-    const pipeline_data = (self.state.pipeline orelse return VkError.InvalidHandleDrv).interface.mode.graphics;
-    const rasterization = pipeline_data.rasterization;
-    const cull_mode = rasterization.cull_mode;
-
-    if (!cull_mode.front_bit and !cull_mode.back_bit)
-        return false;
-
-    if (cull_mode.front_bit and cull_mode.back_bit)
-        return true;
-
-    const area = triangleArea2(v0, v1, v2);
-    if (area == 0.0)
-        return true;
-
-    const front_face = switch (rasterization.front_face) {
-        .counter_clockwise => area < 0.0,
-        .clockwise => area > 0.0,
-        else => return false,
-    };
-
-    return (cull_mode.front_bit and front_face) or (cull_mode.back_bit and !front_face);
-}
-
 fn rasterizeTriangle(
     self: *Self,
     allocator: std.mem.Allocator,
@@ -333,3 +341,75 @@ fn fragmentShaderStage(self: *Self, draw_call: *DrawCall) !void {
     }
     wg.await(self.device.interface.io()) catch return VkError.DeviceLost;
 }
+
+fn readIndexBuffer(self: *Self, allocator: std.mem.Allocator, index_count: usize, first_index: usize, vertex_offset: usize) VkError![]u32 {
+    const index_buffer = self.state.data.graphics.index_buffer;
+    const buffer = index_buffer.buffer;
+    const buffer_memory = if (buffer.interface.memory) |memory| memory else return VkError.InvalidDeviceMemoryDrv;
+    const index_size = indexTypeSize(index_buffer.index_type) orelse {
+        base.unsupported("index type {any}", .{index_buffer.index_type});
+        return VkError.Unknown;
+    };
+
+    const byte_offset = buffer.interface.offset + index_buffer.offset + (first_index * index_size);
+    const byte_size = index_count * index_size;
+    const index_memory: []const u8 = @as([*]const u8, @ptrCast(@alignCast(try buffer_memory.map(byte_offset, byte_size))))[0..byte_size];
+
+    const indices = allocator.alloc(u32, index_count) catch return VkError.OutOfDeviceMemory;
+    for (indices, 0..) |*index, i| {
+        const offset = i * index_size;
+        const raw_index: u32 = switch (index_size) {
+            1 => index_memory[offset],
+            2 => std.mem.readInt(u16, index_memory[offset..][0..2], .little),
+            4 => @intCast(std.mem.readInt(u32, index_memory[offset..][0..4], .little)),
+            else => unreachable,
+        };
+        index.* = @intCast(vertex_offset + raw_index);
+    }
+
+    return indices;
+}
+
+fn indexTypeSize(index_type: vk.IndexType) ?usize {
+    return switch (index_type) {
+        .uint8 => 1,
+        .uint16 => 2,
+        .uint32 => 4,
+        else => null,
+    };
+}
+
+fn triangleArea2(v0: *const Vertex, v1: *const Vertex, v2: *const Vertex) f32 {
+    const x0 = v0.position[0];
+    const y0 = v0.position[1];
+    const x1 = v1.position[0];
+    const y1 = v1.position[1];
+    const x2 = v2.position[0];
+    const y2 = v2.position[1];
+
+    return ((x1 - x0) * (y2 - y0)) - ((y1 - y0) * (x2 - x0));
+}
+
+fn triangleIsCulled(self: *Self, v0: *const Vertex, v1: *const Vertex, v2: *const Vertex) VkError!bool {
+    const pipeline_data = (self.state.pipeline orelse return VkError.InvalidHandleDrv).interface.mode.graphics;
+    const rasterization = pipeline_data.rasterization;
+    const cull_mode = rasterization.cull_mode;
+
+    if (!cull_mode.front_bit and !cull_mode.back_bit)
+        return false;
+
+    if (cull_mode.front_bit and cull_mode.back_bit)
+        return true;
+
+    const area = triangleArea2(v0, v1, v2);
+    if (area == 0.0)
+        return true;
+
+    const front_face = switch (rasterization.front_face) {
+        .counter_clockwise => area < 0.0,
+        .clockwise => area > 0.0,
+        else => return false,
+    };
+
+    return (cull_mode.front_bit and front_face) or (cull_mode.back_bit and !front_face);
+}

src/soft/device/vertex_dispatcher.zig

@@ -18,6 +18,9 @@ pub const RunData = struct {
     batch_id: usize,
     batch_size: usize,
     vertex_count: usize,
+    first_vertex: usize,
+    first_instance: usize,
+    indices: ?[]const u32,
     instance_index: usize,
     draw_call: *Renderer.DrawCall,
 };
@@ -41,7 +44,10 @@ inline fn run(data: RunData) !void {
 
     var invocation_index: usize = data.batch_id;
     while (invocation_index < data.vertex_count) : (invocation_index += data.batch_size) {
-        setupBuiltins(rt, invocation_index, data.instance_index) catch |err| switch (err) {
+        const vertex_index = if (data.indices) |indices| indices[invocation_index] else data.first_vertex + invocation_index;
+        const instance_index = data.first_instance + data.instance_index;
+
+        setupBuiltins(rt, vertex_index, instance_index) catch |err| switch (err) {
             SpvRuntimeError.NotFound => {},
             else => return err,
         };
@@ -56,7 +62,7 @@ inline fn run(data: RunData) !void {
                 const buffer = vertex_buffer.buffer;
                 const buffer_memory_size = base.format.texelSize(attribute.format);
                 const buffer_memory = if (buffer.interface.memory) |memory| memory else return VkError.InvalidDeviceMemoryDrv;
-                const offset = buffer.interface.offset + (binding_info.stride * invocation_index) + attribute.offset;
+                const offset = buffer.interface.offset + vertex_buffer.offset + (binding_info.stride * vertex_index) + attribute.offset;
 
                 const buffer_memory_map: []u8 = @as([*]u8, @ptrCast(@alignCast(try buffer_memory.map(offset, buffer_memory_size))))[0..buffer_memory_size];
 
@@ -89,7 +95,7 @@ inline fn run(data: RunData) !void {
     }
 }
 
-fn setupBuiltins(rt: *spv.Runtime, invocation_index: usize, instance_index: usize) !void {
-    try rt.writeBuiltIn(std.mem.asBytes(&invocation_index), .VertexIndex);
+fn setupBuiltins(rt: *spv.Runtime, vertex_index: usize, instance_index: usize) !void {
+    try rt.writeBuiltIn(std.mem.asBytes(&vertex_index), .VertexIndex);
     try rt.writeBuiltIn(std.mem.asBytes(&instance_index), .InstanceIndex);
 }