diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/3rdparty/autotrace/spline.c | |
parent | Initial commit. (diff) | |
download | inkscape-upstream/1.2.2.tar.xz inkscape-upstream/1.2.2.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/3rdparty/autotrace/spline.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/3rdparty/autotrace/spline.c b/src/3rdparty/autotrace/spline.c new file mode 100644 index 0000000..3aa0f73 --- /dev/null +++ b/src/3rdparty/autotrace/spline.c @@ -0,0 +1,160 @@ +/* spline.c: spline and spline list (represented as arrays) manipulation. */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif /* Def: HAVE_CONFIG_H */ + +#include "logreport.h" +#include "types.h" +#include "spline.h" +#include "vector.h" +#include "xstd.h" +#include <assert.h> + +/* Print a spline in human-readable form. */ + +void print_spline(spline_type s) +{ + assert(SPLINE_DEGREE(s) == LINEARTYPE || SPLINE_DEGREE(s) == CUBICTYPE); + + if (SPLINE_DEGREE(s) == LINEARTYPE) + fprintf(stdout, "(%.3f,%.3f)--(%.3f,%.3f).\n", START_POINT(s).x, START_POINT(s).y, END_POINT(s).x, END_POINT(s).y); + + else if (SPLINE_DEGREE(s) == CUBICTYPE) + fprintf(stdout, "(%.3f,%.3f)..ctrls(%.3f,%.3f)&(%.3f,%.3f)..(%.3f,%.3f).\n", START_POINT(s).x, START_POINT(s).y, CONTROL1(s).x, CONTROL1(s).y, CONTROL2(s).x, CONTROL2(s).y, END_POINT(s).x, END_POINT(s).y); +} + +/* Evaluate the spline S at a given T value. This is an implementation + of de Casteljau's algorithm. See Schneider's thesis, p.37. + The variable names are taken from there. */ + +at_real_coord evaluate_spline(spline_type s, gfloat t) +{ + spline_type V[4]; /* We need degree+1 splines, but assert degree <= 3. */ + signed i, j; + gfloat one_minus_t = (gfloat) 1.0 - t; + polynomial_degree degree = SPLINE_DEGREE(s); + + for (i = 0; i <= degree; i++) { + V[0].v[i].x = s.v[i].x; + V[0].v[i].y = s.v[i].y; + V[0].v[i].z = s.v[i].z; + } + + for (j = 1; j <= degree; j++) + for (i = 0; i <= degree - j; i++) { + at_real_coord t1 = Pmult_scalar(V[j - 1].v[i], one_minus_t); + at_real_coord t2 = Pmult_scalar(V[j - 1].v[i + 1], t); + at_real_coord temp = Padd(t1, t2); + V[j].v[i].x = temp.x; + V[j].v[i].y = temp.y; + V[j].v[i].z = temp.z; + } + + return V[degree].v[0]; +} + +/* Return a new, empty, spline list. */ + +spline_list_type *new_spline_list(void) +{ + spline_list_type *answer; + + XMALLOC(answer, sizeof(spline_list_type)); + *answer = empty_spline_list(); + return answer; +} + +spline_list_type empty_spline_list(void) +{ + spline_list_type answer; + SPLINE_LIST_DATA(answer) = NULL; + SPLINE_LIST_LENGTH(answer) = 0; + return answer; +} + +/* Return a new spline list with SPLINE as the first element. */ + +spline_list_type *new_spline_list_with_spline(spline_type spline) +{ + spline_list_type *answer; + + answer = new_spline_list(); + XMALLOC(SPLINE_LIST_DATA(*answer), sizeof(spline_type)); + SPLINE_LIST_ELT(*answer, 0) = spline; + SPLINE_LIST_LENGTH(*answer) = 1; + + return answer; +} + +/* Free the storage in a spline list. We don't have to free the + elements, since they are arrays in automatic storage. And we don't + want to free the list if it was empty. */ + +void free_spline_list(spline_list_type spline_list) +{ + free(SPLINE_LIST_DATA(spline_list)); +} + +/* Append the spline S to the list SPLINE_LIST. */ + +void append_spline(spline_list_type * l, spline_type s) +{ + assert(l != NULL); + + SPLINE_LIST_LENGTH(*l)++; + XREALLOC(SPLINE_LIST_DATA(*l), SPLINE_LIST_LENGTH(*l) * sizeof(spline_type)); + LAST_SPLINE_LIST_ELT(*l) = s; +} + +/* Tack the elements in the list S2 onto the end of S1. + S2 is not changed. */ + +void concat_spline_lists(spline_list_type * s1, spline_list_type s2) +{ + unsigned this_spline; + unsigned new_length; + + assert(s1 != NULL); + + new_length = SPLINE_LIST_LENGTH(*s1) + SPLINE_LIST_LENGTH(s2); + + XREALLOC(SPLINE_LIST_DATA(*s1), new_length * sizeof(spline_type)); + + for (this_spline = 0; this_spline < SPLINE_LIST_LENGTH(s2); this_spline++) + SPLINE_LIST_ELT(*s1, SPLINE_LIST_LENGTH(*s1)++) + = SPLINE_LIST_ELT(s2, this_spline); +} + +/* Return a new, empty, spline list array. */ + +spline_list_array_type new_spline_list_array(void) +{ + spline_list_array_type answer; + + SPLINE_LIST_ARRAY_DATA(answer) = NULL; + SPLINE_LIST_ARRAY_LENGTH(answer) = 0; + + return answer; +} + +/* Free the storage in a spline list array. We don't + want to free the list if it is empty. */ +void free_spline_list_array(spline_list_array_type * spline_list_array) +{ + unsigned this_list; + + for (this_list = 0; this_list < SPLINE_LIST_ARRAY_LENGTH(*spline_list_array); this_list++) + free_spline_list(SPLINE_LIST_ARRAY_ELT(*spline_list_array, this_list)); + + free(SPLINE_LIST_ARRAY_DATA(*spline_list_array)); +} + +/* Append the spline S to the list SPLINE_LIST_ARRAY. */ + +void append_spline_list(spline_list_array_type * l, spline_list_type s) +{ + SPLINE_LIST_ARRAY_LENGTH(*l)++; + XREALLOC(SPLINE_LIST_ARRAY_DATA(*l), SPLINE_LIST_ARRAY_LENGTH(*l) * sizeof(spline_list_type)); + LAST_SPLINE_LIST_ARRAY_ELT(*l) = s; +} |