1 files changed, 52 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/render_pipeline/stage_spot.cc b/third_party/jpeg-xl/lib/jxl/render_pipeline/stage_spot.cc
new file mode 100644
index 0000000000..d4f6152994
--- /dev/null
+++ b/third_party/jpeg-xl/lib/jxl/render_pipeline/stage_spot.cc
@@ -0,0 +1,52 @@
+// Copyright (c) the JPEG XL Project Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "lib/jxl/render_pipeline/stage_spot.h"
+
+namespace jxl {
+class SpotColorStage : public RenderPipelineStage {
+ public:
+  explicit SpotColorStage(size_t spot_c, const float* spot_color)
+      : RenderPipelineStage(RenderPipelineStage::Settings()),
+        spot_c_(spot_c),
+        spot_color_(spot_color) {
+    JXL_ASSERT(spot_c_ >= 3);
+  }
+
+  void ProcessRow(const RowInfo& input_rows, const RowInfo& output_rows,
+                  size_t xextra, size_t xsize, size_t xpos, size_t ypos,
+                  size_t thread_id) const final {
+    // TODO(veluca): add SIMD.
+    PROFILER_ZONE("RenderSpotColors");
+    float scale = spot_color_[3];
+    for (size_t c = 0; c < 3; c++) {
+      float* JXL_RESTRICT p = GetInputRow(input_rows, c, 0);
+      const float* JXL_RESTRICT s = GetInputRow(input_rows, spot_c_, 0);
+      for (ssize_t x = -xextra; x < ssize_t(xsize + xextra); x++) {
+        float mix = scale * s[x];
+        p[x] = mix * spot_color_[c] + (1.0f - mix) * p[x];
+      }
+    }
+  }
+
+  RenderPipelineChannelMode GetChannelMode(size_t c) const final {
+    return c < 3          ? RenderPipelineChannelMode::kInPlace
+           : c == spot_c_ ? RenderPipelineChannelMode::kInput
+                          : RenderPipelineChannelMode::kIgnored;
+  }
+
+  const char* GetName() const override { return "Spot"; }
+
+ private:
+  size_t spot_c_;
+  const float* spot_color_;
+};
+
+std::unique_ptr<RenderPipelineStage> GetSpotColorStage(
+    size_t spot_c, const float* spot_color) {
+  return jxl::make_unique<SpotColorStage>(spot_c, spot_color);
+}
+
+}  // namespace jxl