Refactor FourCC magic uses

- Use new fourcc_t type
- Improves compiler compatibility by removing multi chars

src/xenia/gpu/command_processor.cc

@@ -824,8 +824,8 @@ bool CommandProcessor::ExecutePacketType3_XE_SWAP(RingBuffer* reader,
   // VdSwap will post this to tell us we need to swap the screen/fire an
   // interrupt.
   // 63 words here, but only the first has any data.
-  uint32_t magic = reader->ReadAndSwap<uint32_t>();
-  assert_true(magic == 'SWAP');
+  uint32_t magic = reader->ReadAndSwap<fourcc_t>();
+  assert_true(magic == kSwapSignature);
 
   // TODO(benvanik): only swap frontbuffer ptr.
   uint32_t frontbuffer_ptr = reader->ReadAndSwap<uint32_t>();

src/xenia/gpu/texture_dump.cc

@@ -30,7 +30,7 @@ void TextureDump(const TextureInfo& src, void* buffer, size_t length) {
     struct {
       uint32_t size;
       uint32_t flags;
-      uint32_t fourcc;
+      be<fourcc_t> fourcc;
       uint32_t rgb_bit_count;
       uint32_t r_bit_mask;
       uint32_t g_bit_mask;
@@ -59,17 +59,17 @@ void TextureDump(const TextureInfo& src, void* buffer, size_t length) {
   switch (src.format) {
     case xenos::TextureFormat::k_DXT1: {
       dds_header.pixel_format.flags = 0x4u;
-      dds_header.pixel_format.fourcc = '1TXD';
+      dds_header.pixel_format.fourcc = make_fourcc("DXT1");
       break;
     }
     case xenos::TextureFormat::k_DXT2_3: {
       dds_header.pixel_format.flags = 0x4u;
-      dds_header.pixel_format.fourcc = '3TXD';
+      dds_header.pixel_format.fourcc = make_fourcc("DXT3");
       break;
     }
     case xenos::TextureFormat::k_DXT4_5: {
       dds_header.pixel_format.flags = 0x4u;
-      dds_header.pixel_format.fourcc = '5TXD';
+      dds_header.pixel_format.fourcc = make_fourcc("DXT5");
       break;
     }
     case xenos::TextureFormat::k_8_8_8_8: {
@@ -100,7 +100,7 @@ void TextureDump(const TextureInfo& src, void* buffer, size_t length) {
 
   FILE* handle = filesystem::OpenFile(path, "wb");
   if (handle) {
-    const uint32_t signature = ' SDD';
+    const char signature[4] = {'D', 'D', 'S', ' '};
     fwrite(&signature, sizeof(signature), 1, handle);
     fwrite(&dds_header, sizeof(dds_header), 1, handle);
     fwrite(buffer, 1, length, handle);

src/xenia/gpu/xenos.h

@@ -15,6 +15,7 @@
 #include "xenia/base/assert.h"
 #include "xenia/base/byte_order.h"
 #include "xenia/base/math.h"
+#include "xenia/base/memory.h"
 #include "xenia/base/platform.h"
 
 namespace xe {
@@ -27,6 +28,8 @@ namespace xenos {
 // in bit fields (registers are 32-bit, and the microcode consists of triples of
 // 32-bit words).
 
+constexpr fourcc_t kSwapSignature = make_fourcc("SWAP");
+
 enum class ShaderType : uint32_t {
   kVertex = 0,
   kPixel = 1,