MSL: Support remapping constexpr samplers by set/binding.

Older API was oriented around IDs which are not available unless you're
doing full reflection, which is awkward for certain use cases which know
their set/bindings up front.

Optimize resource bindings to be hashmap rather than doing linear seeks
all the time.

2 files changed, 85 insertions, 0 deletions

diff --git a/tests-other/msl_constexpr_test.cpp b/tests-other/msl_constexpr_test.cpp
new file mode 100644
index 00000000..e3d791f7
--- /dev/null
+++ b/tests-other/msl_constexpr_test.cpp
@@ -0,0 +1,85 @@
+// Testbench for MSL constexpr samplers.
+// It does not validate output, but it's useful for ad-hoc testing.
+
+#ifdef _MSC_VER
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include <spirv_cross_c.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <vector>
+
+#define SPVC_CHECKED_CALL(x) do { \
+	if ((x) != SPVC_SUCCESS) { \
+		fprintf(stderr, "Failed at line %d.\n", __LINE__); \
+		exit(1); \
+	} \
+} while(0)
+#define SPVC_CHECKED_CALL_NEGATIVE(x) do { \
+	g_fail_on_error = SPVC_FALSE; \
+	if ((x) == SPVC_SUCCESS) { \
+		fprintf(stderr, "Failed at line %d.\n", __LINE__); \
+		exit(1); \
+	} \
+	g_fail_on_error = SPVC_TRUE; \
+} while(0)
+
+static std::vector<SpvId> read_file(const char *path)
+{
+	long len;
+	FILE *file = fopen(path, "rb");
+
+	if (!file)
+		return {};
+
+	fseek(file, 0, SEEK_END);
+	len = ftell(file);
+	rewind(file);
+
+	std::vector<SpvId> buffer(len / sizeof(SpvId));
+	if (fread(buffer.data(), 1, len, file) != (size_t)len)
+	{
+		fclose(file);
+		return {};
+	}
+
+	fclose(file);
+	return buffer;
+}
+
+int main(int argc, char **argv)
+{
+	if (argc != 2)
+		return EXIT_FAILURE;
+
+	auto buffer = read_file(argv[1]);
+	if (buffer.empty())
+		return EXIT_FAILURE;
+
+	spvc_context ctx;
+	spvc_parsed_ir parsed_ir;
+	spvc_compiler compiler;
+
+	SPVC_CHECKED_CALL(spvc_context_create(&ctx));
+	SPVC_CHECKED_CALL(spvc_context_parse_spirv(ctx, buffer.data(), buffer.size(), &parsed_ir));
+	SPVC_CHECKED_CALL(spvc_context_create_compiler(ctx, SPVC_BACKEND_MSL, parsed_ir, SPVC_CAPTURE_MODE_TAKE_OWNERSHIP, &compiler));
+
+	spvc_msl_constexpr_sampler samp;
+	spvc_msl_constexpr_sampler_init(&samp);
+	samp.s_address = SPVC_MSL_SAMPLER_ADDRESS_REPEAT;
+	samp.t_address = SPVC_MSL_SAMPLER_ADDRESS_REPEAT;
+	samp.r_address = SPVC_MSL_SAMPLER_ADDRESS_REPEAT;
+	SPVC_CHECKED_CALL(spvc_compiler_msl_remap_constexpr_sampler_by_binding(compiler, 1, 3, &samp));
+
+	samp.s_address = SPVC_MSL_SAMPLER_ADDRESS_CLAMP_TO_EDGE;
+	samp.t_address = SPVC_MSL_SAMPLER_ADDRESS_CLAMP_TO_EDGE;
+	samp.r_address = SPVC_MSL_SAMPLER_ADDRESS_CLAMP_TO_EDGE;
+	SPVC_CHECKED_CALL(spvc_compiler_msl_remap_constexpr_sampler_by_binding(compiler, 2, 2, &samp));
+
+	const char *str;
+	SPVC_CHECKED_CALL(spvc_compiler_compile(compiler, &str));
+
+	fprintf(stderr, "Output:\n%s\n", str);
+}
+
diff --git a/tests-other/msl_constexpr_test.spv b/tests-other/msl_constexpr_test.spv
new file mode 100644
index 00000000..2b3de4ba
--- /dev/null
+++ b/tests-other/msl_constexpr_test.spv