Masking support for motion tracks

Added option to use Grease Pencil datablock as a mask for pattern
when doing motion tracking. Option could be found in Tracking Settings
panel.

All strokes would be rasterized separately from each other and every
stroke is treating as a closed spline.

Also added option to apply a mask on track preview which is situated
just after B/B/W channel button under track preview.

4 files changed, 49 insertions, 17 deletions

diff --git a/extern/libmv/libmv-capi.cpp b/extern/libmv/libmv-capi.cpp
index 8751e1e190b..3d3b7398c9b 100644
--- a/extern/libmv/libmv-capi.cpp
+++ b/extern/libmv/libmv-capi.cpp
@@ -243,7 +243,7 @@ void savePNGImage(png_bytep *row_pointers, int width, int height, int depth, int
 	fclose(fp);
 }
 
-static void saveImage(char *prefix, libmv::FloatImage image, int x0, int y0)
+static void saveImage(const char *prefix, libmv::FloatImage image, int x0, int y0)
 {
 	int x, y;
 	png_bytep *row_pointers;
@@ -283,7 +283,7 @@ static void saveImage(char *prefix, libmv::FloatImage image, int x0, int y0)
 	free(row_pointers);
 }
 
-static void saveBytesImage(char *prefix, unsigned char *data, int width, int height)
+static void saveBytesImage(const char *prefix, unsigned char *data, int width, int height)
 {
 	int x, y;
 	png_bytep *row_pointers;
@@ -376,6 +376,8 @@ int libmv_trackRegion(const struct libmv_trackRegionOptions *options,
 	}
 
 	libmv::TrackRegionOptions track_region_options;
+	libmv::FloatImage image1_mask;
+
 	switch (options->motion_model) {
 #define LIBMV_CONVERT(the_model) \
     case libmv::TrackRegionOptions::the_model: \
@@ -398,6 +400,12 @@ int libmv_trackRegion(const struct libmv_trackRegionOptions *options,
 	track_region_options.use_brute_initialization = options->use_brute;
 	track_region_options.use_normalized_intensities = options->use_normalization;
 
+	if (options->image1_mask) {
+		floatBufToImage(options->image1_mask, image1_width, image1_height, 1, &image1_mask);
+
+		track_region_options.image1_mask = &image1_mask;
+	}
+
 	/* Convert from raw float buffers to libmv's FloatImage. */
 	libmv::FloatImage old_patch, new_patch;
 	floatBufToImage(image1, image1_width, image1_height, 1, &old_patch);
@@ -437,15 +445,24 @@ int libmv_trackRegion(const struct libmv_trackRegionOptions *options,
 
 void libmv_samplePlanarPatch(const float *image, int width, int height,
                              int channels, const double *xs, const double *ys,
-                             int num_samples_x, int num_samples_y, float *patch,
+                             int num_samples_x, int num_samples_y,
+                             const float *mask, float *patch,
                              double *warped_position_x, double *warped_position_y)
 {
-	libmv::FloatImage libmv_image, libmv_patch;
+	libmv::FloatImage libmv_image, libmv_patch, libmv_mask;
+	libmv::FloatImage *libmv_mask_for_sample = NULL;
 
 	floatBufToImage(image, width, height, channels, &libmv_image);
 
+	if (mask) {
+		floatBufToImage(mask, width, height, 1, &libmv_mask);
+
+		libmv_mask_for_sample = &libmv_mask;
+	}
+
 	libmv::SamplePlanarPatch(libmv_image, xs, ys, num_samples_x, num_samples_y,
-	                         &libmv_patch, warped_position_x, warped_position_y);
+	                         libmv_mask_for_sample, &libmv_patch,
+	                         warped_position_x, warped_position_y);
 
 	imageToFloatBuf(&libmv_patch, channels, patch);
 }
diff --git a/extern/libmv/libmv-capi.h b/extern/libmv/libmv-capi.h
index fe759b06fe4..fc3b6f94f62 100644
--- a/extern/libmv/libmv-capi.h
+++ b/extern/libmv/libmv-capi.h
@@ -52,18 +52,21 @@ void libmv_regionTrackerDestroy(struct libmv_RegionTracker *libmv_tracker);
 
 /* TrackRegion (new planar tracker) */
 struct libmv_trackRegionOptions {
-  int motion_model;
-  int num_iterations;
-  int use_brute;
-  int use_normalization;
-  double minimum_correlation;
-  double sigma;
+	int motion_model;
+	int num_iterations;
+	int use_brute;
+	int use_normalization;
+	double minimum_correlation;
+	double sigma;
+	float *image1_mask;
 };
+
 struct libmv_trackRegionResult {
-  int termination;
-  const char *termination_reason;
-  double correlation;
+	int termination;
+	const char *termination_reason;
+	double correlation;
 };
+
 int libmv_trackRegion(const struct libmv_trackRegionOptions *options,
                       const float *image1, int image1_width, int image1_height,
                       const float *image2, int image2_width, int image2_height,
@@ -73,7 +76,8 @@ int libmv_trackRegion(const struct libmv_trackRegionOptions *options,
 
 void libmv_samplePlanarPatch(const float *image, int width, int height,
                              int channels, const double *xs, const double *ys,
-                             int num_samples_x, int num_samples_y, float *patch,
+                             int num_samples_x, int num_samples_y,
+                             const float *mask, float *patch,
                              double *warped_position_x, double *warped_position_y);
 
 /* Tracks */
diff --git a/extern/libmv/libmv/tracking/track_region.cc b/extern/libmv/libmv/tracking/track_region.cc
index e65ead50c80..f52919b2a61 100644
--- a/extern/libmv/libmv/tracking/track_region.cc
+++ b/extern/libmv/libmv/tracking/track_region.cc
@@ -1351,7 +1351,7 @@ void TrackRegion(const FloatImage &image1,
 bool SamplePlanarPatch(const FloatImage &image,
                        const double *xs, const double *ys,
                        int num_samples_x, int num_samples_y,
-                       FloatImage *patch,
+                       FloatImage *mask, FloatImage *patch,
                        double *warped_position_x, double *warped_position_y) {
   // Bail early if the points are outside the image.
   if (!AllInBounds(image, xs, ys)) {
@@ -1376,6 +1376,13 @@ bool SamplePlanarPatch(const FloatImage &image,
       SampleLinear(image, image_position(1),
                    image_position(0),
                    &(*patch)(r, c, 0));
+      if (mask) {
+        float maskValue = SampleLinear(*mask, image_position(1),
+                                       image_position(0), 0);
+
+        for (int d = 0; d < image.Depth(); d++)
+          (*patch)(r, c, d) *= maskValue;
+      }
     }
   }
 
diff --git a/extern/libmv/libmv/tracking/track_region.h b/extern/libmv/libmv/tracking/track_region.h
index 0de11239da6..22ecfc54a15 100644
--- a/extern/libmv/libmv/tracking/track_region.h
+++ b/extern/libmv/libmv/tracking/track_region.h
@@ -135,10 +135,14 @@ void TrackRegion(const FloatImage &image1,
 // pixels of border around them. (so e.g. a corner of the patch cannot lie
 // directly on the edge of the image). Four corners are always required. All
 // channels are interpolated.
+// When mask is not null it'll be used as a pattern mask. Ot should match
+// the size of image.
+// Warped coordinates of marker's position would be returned in
+// warped_position_x and warped_position_y
 bool SamplePlanarPatch(const FloatImage &image,
                        const double *xs, const double *ys,
                        int num_samples_x, int num_samples_y,
-                       FloatImage *patch,
+                       FloatImage *mask, FloatImage *patch,
                        double *warped_position_x, double *warped_position_y);
 
 }  // namespace libmv