Implement morphing functions and adapt blender

Signed-off-by: pacien <pacien.trangirard@pacien.net>

5 files changed, 109 insertions, 8 deletions

diff --git a/include/blender/blender.h b/include/blender/blender.h
index 8e89208..26ff802 100644
--- a/include/blender/blender.h
+++ b/include/blender/blender.h
@@ -8,7 +8,7 @@
 
 #include "common/time.h"
 #include "blender/canvas.h"
-#include "morpher/morpher.h"
+#include "morpher/morphing.h"
 
 /**
  * Function: blender_blend_canvas
diff --git a/include/morpher/morphing.h b/include/morpher/morphing.h
new file mode 100644
index 0000000..028cd87
--- /dev/null
+++ b/include/morpher/morphing.h
@@ -0,0 +1,58 @@
+#ifndef UPEM_MORPHING_MORPHING
+#define UPEM_MORPHING_MORPHING
+
+/**
+ * File: morphing.h
+ * Coordinate mapping for morphing transforms.
+ */
+
+#include "common/geom.h"
+#include "common/time.h"
+#include "morpher/trianglemap.h"
+
+/**
+ * Struct: Morphing
+ * Represents an abstract coordinate transform from a source to a destination coordinate matrix,
+ * constrained by a given set of points.
+ *
+ * Fields:
+ *   dim     - dimension in pixels
+ *   *first  - the first triangle in the linked list
+ *   *center - the center triangle
+ */
+typedef struct {
+  CartesianVector dim;
+  TriangleMap *first, *center;
+} Morphing;
+
+/**
+ * Function: morphing_init
+ * Initialises a morphing.
+ *
+ * Parameters:
+ *   width  - coordinate matrix width in pixels
+ *   height - coordinate matrix height in pixels
+ */
+Morphing *morphing_create(IntVector width, IntVector height);
+
+/**
+ * Function: morphing_free
+ * Frees any resources allocated to a morphing.
+ *
+ * Parameters:
+ *   *m - pointer to the morphing to destroy
+ */
+void morphing_destroy(Morphing *m);
+
+/**
+ * Function: morphing_add_constraint
+ * Adds a constraint point to a morphing.
+ *
+ * Parameters:
+ *   *m          - pointer to the morphing to alter
+ *   origin      - constraint point coordinates on the origin matrix
+ *   destination - constraint point coordinates on the target matrix
+ */
+void morphing_add_constraint(Morphing *m, CartesianVector origin, CartesianVector destination);
+
+#endif
diff --git a/src/blender/blender.c b/src/blender/blender.c
index 99abedd..08cafa4 100644
--- a/src/blender/blender.c
+++ b/src/blender/blender.c
@@ -1,7 +1,6 @@
 #include "blender/blender.h"
 #include <assert.h>
 #include <math.h>
-#include "morpher/morpher.h"
 
 static inline ColorComponent blend_components(ColorComponent origin, ColorComponent target, TimeVector frame) {
   // https://www.youtube.com/watch?v=LKnqECcg6Gw
@@ -21,7 +20,7 @@ void blender_blend_canvas(Canvas *canvas, Canvas *source, Canvas *target, Morphi
   CartesianMapping mapping;
   Color pixel;
 
-  dim = morpher_get_dim(morphing);
+  dim = morphing->dim;
 
   assert(dim.x > 0 && dim.y > 0);
   assert(vector_equals(dim, canvas_get_dim(canvas)));
@@ -33,7 +32,7 @@ void blender_blend_canvas(Canvas *canvas, Canvas *source, Canvas *target, Morphi
     point.x = flat_dim % dim.y;
     point.y = flat_dim / dim.y;
 
-    mapping = morpher_get_point_mapping(morphing, point, frame);
+    mapping = (CartesianMapping) {point, point};
     pixel = blend_colors(canvas_get_pixel(source, mapping.origin), canvas_get_pixel(target, mapping.target), frame);
     canvas_set_pixel(canvas, point, pixel);
   }
diff --git a/src/morpher/morphing.c b/src/morpher/morphing.c
new file mode 100644
index 0000000..2ab22d0
--- /dev/null
+++ b/src/morpher/morphing.c
@@ -0,0 +1,44 @@
+#include "morpher/morphing.h"
+#include "common/mem.h"
+
+static inline TriangleMap *init_trianglemap(IntVector width, IntVector height) {
+  TriangleMap *bottom_left = trianglemap_create(m(0, 0), m(0, height), m(width, height));
+  TriangleMap *top_right = trianglemap_create(m(0, 0), m(width, height), m(width, 0));
+  trianglemap_set_neighbors(bottom_left, NULL, NULL, top_right, top_right);
+  trianglemap_set_neighbors(top_right, bottom_left, NULL, NULL, NULL);
+  return bottom_left;
+}
+
+static inline TriangleMap *find_triangle(TriangleMap *start, CartesianVector target) {
+  TriangleMap *t = trianglemap_to(start, target);
+  return t == start ? t : find_triangle(t, target);
+}
+
+static inline void update_center(Morphing *m) {
+  m->center = find_triangle(m->center, v(m->dim.x / 2, m->dim.y / 2));
+}
+
+static inline void ensure_delaunay_neighborhood(TriangleMap *t) {
+  trianglemap_propagate_delaunay(t);
+  trianglemap_propagate_delaunay(t->next);
+  trianglemap_propagate_delaunay(t->next->next);
+}
+
+Morphing *morphing_create(IntVector width, IntVector height) {
+  Morphing *m = malloc_or_die(sizeof(Morphing));
+  m->dim = (CartesianVector) {width, height};
+  m->first = init_trianglemap(width, height);
+  m->center = m->first;
+  return m;
+}
+
+void morphing_destroy(Morphing *m) {
+  while (m->first != NULL) m->first = trianglemap_destroy(m->first);
+}
+
+void morphing_add_constraint(Morphing *m, CartesianVector origin, CartesianVector destination) {
+  TriangleMap *target = find_triangle(m->center, origin);
+  TriangleMap *split = trianglemap_split(target, (CartesianMapping) {origin, destination});
+  ensure_delaunay_neighborhood(split);
+  update_center(m);
+}
diff --git a/test/blender/blender.c b/test/blender/blender.c
index bf16dc6..f42322f 100644
--- a/test/blender/blender.c
+++ b/test/blender/blender.c
@@ -2,11 +2,11 @@
 #include <assert.h>
 
 static void test_canvas_blending() {
-  Morphing morphing;
+  Morphing *morphing;
   Canvas origin, target, result;
   CartesianVector sample_point = {13, 17};
 
-  morpher_init(&morphing, 64, 64);
+  morphing = morphing_create(64, 64);
   canvas_init(&origin, 64, 64);
   canvas_init(&target, 64, 64);
   canvas_init(&result, 64, 64);
@@ -14,13 +14,13 @@ static void test_canvas_blending() {
   canvas_set_pixel(&origin, sample_point, (Color) {{0xFF, 0xED, 0x00, 0x00}});
   canvas_set_pixel(&target, sample_point, (Color) {{0x00, 0x47, 0xAB, 0x00}});
 
-  blender_blend_canvas(&result, &origin, &target, &morphing, 0.125);
+  blender_blend_canvas(&result, &origin, &target, morphing, 0.125);
   assert(color_equals(canvas_get_pixel(&result, sample_point), (Color) {{0xEE, 0xDF, 0x3C, 0x00}}));
 
   canvas_free(&result);
   canvas_free(&target);
   canvas_free(&origin);
-  morpher_free(&morphing);
+  morphing_destroy(morphing);
 }
 
 int main(int argc, char **argv) {