webp: Make it a module and unbundle libwebp thirdparty files

Note that there are two Godot-specific changes made to libwebp
for the javascript/HTML5 platform. They are documented in the
README.md.

1 files changed, 67 insertions, 0 deletions

diff --git a/thirdparty/libwebp/dsp/argb_sse2.c b/thirdparty/libwebp/dsp/argb_sse2.c
new file mode 100644
index 0000000000..afcb1957e7
--- /dev/null
+++ b/thirdparty/libwebp/dsp/argb_sse2.c
@@ -0,0 +1,67 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+//   ARGB making functions (SSE2 version).
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include "./dsp.h"
+
+#if defined(WEBP_USE_SSE2)
+
+#include <assert.h>
+#include <emmintrin.h>
+#include <string.h>
+
+static WEBP_INLINE uint32_t MakeARGB32(int a, int r, int g, int b) {
+  return (((uint32_t)a << 24) | (r << 16) | (g << 8) | b);
+}
+
+static void PackARGB(const uint8_t* a, const uint8_t* r, const uint8_t* g,
+                     const uint8_t* b, int len, uint32_t* out) {
+  if (g == r + 1) {  // RGBA input order. Need to swap R and B.
+    int i = 0;
+    const int len_max = len & ~3;  // max length processed in main loop
+    const __m128i red_blue_mask = _mm_set1_epi32(0x00ff00ffu);
+    assert(b == r + 2);
+    assert(a == r + 3);
+    for (; i < len_max; i += 4) {
+      const __m128i A = _mm_loadu_si128((const __m128i*)(r + 4 * i));
+      const __m128i B = _mm_and_si128(A, red_blue_mask);     // R 0 B 0
+      const __m128i C = _mm_andnot_si128(red_blue_mask, A);  // 0 G 0 A
+      const __m128i D = _mm_shufflelo_epi16(B, _MM_SHUFFLE(2, 3, 0, 1));
+      const __m128i E = _mm_shufflehi_epi16(D, _MM_SHUFFLE(2, 3, 0, 1));
+      const __m128i F = _mm_or_si128(E, C);
+      _mm_storeu_si128((__m128i*)(out + i), F);
+    }
+    for (; i < len; ++i) {
+      out[i] = MakeARGB32(a[4 * i], r[4 * i], g[4 * i], b[4 * i]);
+    }
+  } else {
+    assert(g == b + 1);
+    assert(r == b + 2);
+    assert(a == b + 3);
+    memcpy(out, b, len * 4);
+  }
+}
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8EncDspARGBInitSSE2(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspARGBInitSSE2(void) {
+  VP8PackARGB = PackARGB;
+}
+
+#else  // !WEBP_USE_SSE2
+
+WEBP_DSP_INIT_STUB(VP8EncDspARGBInitSSE2)
+
+#endif  // WEBP_USE_SSE2