adding builtin support

sandbox/main.zig

@@ -3,12 +3,8 @@ const spv = @import("spv");
 
 const shader_source = @embedFile("shader.spv");
 
-const Input = struct {
-    value: [4]i32 = [4]i32{ 0, 0, 0, 0 },
-};
-
-const Output = struct {
-    value: [4]i32 = [4]i32{ 0, 0, 0, 0 },
+const SSBO = struct {
+    value: [256]i32 = [_]i32{0} ** 256,
 };
 
 pub fn main() !void {
@@ -28,19 +24,31 @@ pub fn main() !void {
 
         const entry = try rt.getEntryPointByName("main");
 
-        var input: Input = .{};
-        var output: Output = .{};
+        var ssbo: SSBO = .{};
 
-        try rt.writeDescriptorSet(allocator, std.mem.asBytes(&input), 0, 0);
-        try rt.writeDescriptorSet(allocator, std.mem.asBytes(&output), 0, 1);
+        for (0..16) |i| {
+            for (0..16) |x| {
+                for (0..16) |y| {
+                    const global_invocation_indices = [3]i32{
+                        @as(i32, @intCast(i * 16 + x)),
+                        @as(i32, @intCast(y)),
+                        1,
+                    };
 
-        try rt.callEntryPoint(allocator, entry);
+                    try rt.writeBuiltIn(std.mem.asBytes(&global_invocation_indices), .GlobalInvocationId);
+                    try rt.writeDescriptorSet(allocator, std.mem.asBytes(&ssbo), 0, 0);
+                    rt.callEntryPoint(allocator, entry) catch |err| switch (err) {
+                        spv.Runtime.RuntimeError.OutOfBounds => continue,
+                        else => return err,
+                    };
+                    try rt.readDescriptorSet(std.mem.asBytes(&ssbo), 0, 0);
+                }
+            }
+        }
 
-        try rt.readDescriptorSet(std.mem.asBytes(&output), 0, 1);
+        std.log.info("Output: {any}", .{ssbo});
 
-        std.log.info("Output: {any}", .{output});
-
-        std.log.info("\nTotal memory used: {d:.3} KB\n", .{@as(f32, @floatFromInt(gpa.total_requested_bytes)) / 1000.0});
+        std.log.info("Total memory used: {d:.3} KB\n", .{@as(f32, @floatFromInt(gpa.total_requested_bytes)) / 1000.0});
     }
     std.log.info("Successfully executed", .{});
 }