basisu: add bindings for basis-universal (supercompressed textures) (#477)

basisu/src/main.zig

@@ -0,0 +1,45 @@
+pub usingnamespace @import("encoder.zig");
+pub usingnamespace @import("transcoder.zig");
+
+pub const BasisTextureFormat = enum(u1) {
+    etc1s = 0,
+    uastc4x4 = 1,
+};
+
+// Test
+
+const t = @import("transcoder.zig");
+const e = @import("encoder.zig");
+const testing = @import("std").testing;
+
+test "reference decls" {
+    testing.refAllDeclsRecursive(t);
+    testing.refAllDeclsRecursive(e);
+}
+
+test "encode/transcode" {
+    // Encode
+    e.init_encoder();
+
+    const params = e.CompressorParams.init(1);
+    params.setGenerateMipMaps(true);
+    params.setBasisFormat(.uastc4x4);
+    params.setPackUASTCFlags(.{ .fastest = true });
+    defer params.deinit();
+
+    const image = params.getImageSource(0);
+    image.fill(@embedFile("../test/ziggy.png"), 379, 316, 4);
+
+    const comp = try e.Compressor.init(params);
+    try comp.process();
+
+    // Transcode
+    t.init_transcoder();
+
+    const trans = try t.Transcoder.init(comp.output());
+    defer trans.deinit();
+
+    var out_buf = try testing.allocator.alloc(u8, try trans.calcTranscodedSize(0, 0, .astc_4x4_rgba));
+    defer testing.allocator.free(out_buf);
+    try trans.transcode(out_buf, 0, 0, .astc_4x4_rgba, .{});
+}