#define _GNU_SOURCE /* for strndup */
#include <assert.h>
+#include <math.h>
#include <string.h>
#include "svgtiny.h"
#include "svgtiny_internal.h"
-#define GRADIENT_DEBUG
+#undef GRADIENT_DEBUG
static svgtiny_code svgtiny_parse_linear_gradient(xmlNode *linear,
struct svgtiny_parse_state *state);
static float svgtiny_parse_gradient_offset(const char *s);
static void svgtiny_path_bbox(float *p, unsigned int n,
float *x0, float *y0, float *x1, float *y1);
+static void svgtiny_invert_matrix(float *m, float *inv);
/**
fprintf(stderr, "svgtiny_find_gradient: id \"%s\"\n", id);
state->linear_gradient_stop_count = 0;
+ state->gradient_x1 = "0%";
+ state->gradient_y1 = "0%";
+ state->gradient_x2 = "100%";
+ state->gradient_y2 = "0%";
+ state->gradient_user_space_on_use = false;
+ state->gradient_transform.a = 1;
+ state->gradient_transform.b = 0;
+ state->gradient_transform.c = 0;
+ state->gradient_transform.d = 1;
+ state->gradient_transform.e = 0;
+ state->gradient_transform.f = 0;
xmlNode *gradient = svgtiny_find_element_by_id(
(xmlNode *) state->document, id);
svgtiny_find_gradient((const char *) href->children->content
+ 1, state);
+ for (xmlAttr *attr = linear->properties; attr; attr = attr->next) {
+ const char *name = (const char *) attr->name;
+ const char *content = (const char *) attr->children->content;
+ if (strcmp(name, "x1") == 0)
+ state->gradient_x1 = content;
+ else if (strcmp(name, "y1") == 0)
+ state->gradient_y1 = content;
+ else if (strcmp(name, "x2") == 0)
+ state->gradient_x2 = content;
+ else if (strcmp(name, "y2") == 0)
+ state->gradient_y2 = content;
+ else if (strcmp(name, "gradientUnits") == 0)
+ state->gradient_user_space_on_use =
+ strcmp(content, "userSpaceOnUse") == 0;
+ else if (strcmp(name, "gradientTransform") == 0) {
+ float a = 1, b = 0, c = 0, d = 1, e = 0, f = 0;
+ char *s = strdup(content);
+ if (!s)
+ return svgtiny_OUT_OF_MEMORY;
+ svgtiny_parse_transform(s, &a, &b, &c, &d, &e, &f);
+ free(s);
+ fprintf(stderr, "transform %g %g %g %g %g %g\n",
+ a, b, c, d, e, f);
+ state->gradient_transform.a = a;
+ state->gradient_transform.b = b;
+ state->gradient_transform.c = c;
+ state->gradient_transform.d = d;
+ state->gradient_transform.e = e;
+ state->gradient_transform.f = f;
+ }
+ }
+
unsigned int i = 0;
for (xmlNode *stop = linear->children; stop; stop = stop->next) {
float offset = -1;
#endif
/* compute gradient vector */
- float gradient_x0 = 0, gradient_y0 = 0,
- gradient_x1 = 1, gradient_y1 = 0.7,
+ fprintf(stderr, "x1 %s, y1 %s, x2 %s, y2 %s\n",
+ state->gradient_x1, state->gradient_y1,
+ state->gradient_x2, state->gradient_y2);
+ float gradient_x0, gradient_y0, gradient_x1, gradient_y1,
gradient_dx, gradient_dy;
- gradient_x0 = object_x0 + gradient_x0 * (object_x1 - object_x0);
- gradient_y0 = object_y0 + gradient_y0 * (object_y1 - object_y0);
- gradient_x1 = object_x0 + gradient_x1 * (object_x1 - object_x0);
- gradient_y1 = object_y0 + gradient_y1 * (object_y1 - object_y0);
+ if (!state->gradient_user_space_on_use) {
+ gradient_x0 = object_x0 +
+ svgtiny_parse_length(state->gradient_x1,
+ object_x1 - object_x0, *state);
+ gradient_y0 = object_y0 +
+ svgtiny_parse_length(state->gradient_y1,
+ object_y1 - object_y0, *state);
+ gradient_x1 = object_x0 +
+ svgtiny_parse_length(state->gradient_x2,
+ object_x1 - object_x0, *state);
+ gradient_y1 = object_y0 +
+ svgtiny_parse_length(state->gradient_y2,
+ object_y1 - object_y0, *state);
+ } else {
+ gradient_x0 = svgtiny_parse_length(state->gradient_x1,
+ state->viewport_width, *state);
+ gradient_y0 = svgtiny_parse_length(state->gradient_y1,
+ state->viewport_height, *state);
+ gradient_x1 = svgtiny_parse_length(state->gradient_x2,
+ state->viewport_width, *state);
+ gradient_y1 = svgtiny_parse_length(state->gradient_y2,
+ state->viewport_height, *state);
+ }
gradient_dx = gradient_x1 - gradient_x0;
gradient_dy = gradient_y1 - gradient_y0;
#ifdef GRADIENT_DEBUG
}
shape->path = p;
shape->path_length = 13;
- shape->fill = svgtiny_TRANSPARENT;
+ shape->fill = svgtiny_TRANSPARENT;
shape->stroke = svgtiny_RGB(0, 0xff, 0);
state->diagram->shape_count++;
}*/
+ /* invert gradient transform for applying to vertices */
+ float trans[6];
+ svgtiny_invert_matrix(&state->gradient_transform.a, trans);
+ fprintf(stderr, "inverse transform %g %g %g %g %g %g\n",
+ trans[0], trans[1], trans[2], trans[3],
+ trans[4], trans[5]);
+
/* compute points on the path for triangle vertices */
+ /* r, r0, r1 are distance along gradient vector */
unsigned int steps = 10;
- float x0, y0, x1, y1;
+ float x0, y0, x0_trans, y0_trans, r0; /* segment start point */
+ float x1, y1, x1_trans, y1_trans, r1; /* segment end point */
+ float c0x, c0y, c1x, c1y; /* segment control points (beziers only) */
float gradient_norm_squared = gradient_dx * gradient_dx +
gradient_dy * gradient_dy;
struct grad_point {
float min_r = 1000;
unsigned int min_pt = 0;
for (unsigned int j = 0; j != n; ) {
- switch ((int) p[j]) {
- case svgtiny_PATH_MOVE:
+ int segment_type = (int) p[j];
+
+ if (segment_type == svgtiny_PATH_MOVE) {
x0 = p[j + 1];
y0 = p[j + 2];
j += 3;
- break;
- case svgtiny_PATH_LINE:
- case svgtiny_PATH_CLOSE:
- if (((int) p[j]) == svgtiny_PATH_LINE) {
- x1 = p[j + 1];
- y1 = p[j + 2];
- j += 3;
- } else {
- x1 = p[1];
- y1 = p[2];
- j++;
- }
- fprintf(stderr, "line: ");
- for (unsigned int z = 0; z != steps; z++) {
- float f, x, y, r;
- f = (float) z / (float) steps;
- x = x0 + f * (x1 - x0);
- y = y0 + f * (y1 - y0);
- r = ((x - gradient_x0) * gradient_dx +
- (y - gradient_y0) * gradient_dy) /
- gradient_norm_squared;
- fprintf(stderr, "(%g %g [%g]) ", x, y, r);
- pts[pts_count].x = x;
- pts[pts_count].y = y;
- pts[pts_count].r = r;
- if (r < min_r) {
- min_r = r;
- min_pt = pts_count;
- }
- pts_count++;
- }
- fprintf(stderr, "\n");
- x0 = x1;
- y0 = y1;
- break;
- case svgtiny_PATH_BEZIER:
- fprintf(stderr, "bezier: ");
- for (unsigned int z = 0; z != steps; z++) {
- float t, x, y, r;
- t = (float) z / (float) steps;
+ continue;
+ }
+
+ assert(segment_type == svgtiny_PATH_CLOSE ||
+ segment_type == svgtiny_PATH_LINE ||
+ segment_type == svgtiny_PATH_BEZIER);
+
+ /* start point (x0, y0) */
+ x0_trans = trans[0]*x0 + trans[2]*y0 + trans[4];
+ y0_trans = trans[1]*x0 + trans[3]*y0 + trans[5];
+ r0 = ((x0_trans - gradient_x0) * gradient_dx +
+ (y0_trans - gradient_y0) * gradient_dy) /
+ gradient_norm_squared;
+ pts[pts_count].x = x0;
+ pts[pts_count].y = y0;
+ pts[pts_count].r = r0;
+ if (r0 < min_r) {
+ min_r = r0;
+ min_pt = pts_count;
+ }
+ pts_count++;
+
+ /* end point (x1, y1) */
+ if (segment_type == svgtiny_PATH_LINE) {
+ x1 = p[j + 1];
+ y1 = p[j + 2];
+ j += 3;
+ } else if (segment_type == svgtiny_PATH_CLOSE) {
+ x1 = p[1];
+ y1 = p[2];
+ j++;
+ } else /* svgtiny_PATH_BEZIER */ {
+ c0x = p[j + 1];
+ c0y = p[j + 2];
+ c1x = p[j + 3];
+ c1y = p[j + 4];
+ x1 = p[j + 5];
+ y1 = p[j + 6];
+ j += 7;
+ }
+ x1_trans = trans[0]*x1 + trans[2]*y1 + trans[4];
+ y1_trans = trans[1]*x1 + trans[3]*y1 + trans[5];
+ r1 = ((x1_trans - gradient_x0) * gradient_dx +
+ (y1_trans - gradient_y0) * gradient_dy) /
+ gradient_norm_squared;
+
+ /* determine steps from change in r */
+ steps = ceilf(fabsf(r1 - r0) / 0.05);
+ if (steps == 0)
+ steps = 1;
+ fprintf(stderr, "r0 %g, r1 %g, steps %i\n",
+ r0, r1, steps);
+
+ /* loop through intermediate points */
+ for (unsigned int z = 1; z != steps; z++) {
+ float t, x, y, x_trans, y_trans, r;
+ t = (float) z / (float) steps;
+ if (segment_type == svgtiny_PATH_BEZIER) {
x = (1-t) * (1-t) * (1-t) * x0 +
- 3 * t * (1-t) * (1-t) * p[j + 1] +
- 3 * t * t * (1-t) * p[j + 3] +
- t * t * t * p[j + 5];
+ 3 * t * (1-t) * (1-t) * c0x +
+ 3 * t * t * (1-t) * c1x +
+ t * t * t * x1;
y = (1-t) * (1-t) * (1-t) * y0 +
- 3 * t * (1-t) * (1-t) * p[j + 2] +
- 3 * t * t * (1-t) * p[j + 4] +
- t * t * t * p[j + 6];
- r = ((x - gradient_x0) * gradient_dx +
- (y - gradient_y0) * gradient_dy) /
+ 3 * t * (1-t) * (1-t) * c0y +
+ 3 * t * t * (1-t) * c1y +
+ t * t * t * y1;
+ } else {
+ x = (1-t) * x0 + t * x1;
+ y = (1-t) * y0 + t * y1;
+ }
+ x_trans = trans[0]*x + trans[2]*y + trans[4];
+ y_trans = trans[1]*x + trans[3]*y + trans[5];
+ r = ((x_trans - gradient_x0) * gradient_dx +
+ (y_trans - gradient_y0) * gradient_dy) /
gradient_norm_squared;
- fprintf(stderr, "(%g %g [%g]) ", x, y, r);
- pts[pts_count].x = x;
- pts[pts_count].y = y;
- pts[pts_count].r = r;
- if (r < min_r) {
- min_r = r;
- min_pt = pts_count;
- }
- pts_count++;
+ fprintf(stderr, "(%g %g [%g]) ", x, y, r);
+ pts[pts_count].x = x;
+ pts[pts_count].y = y;
+ pts[pts_count].r = r;
+ if (r < min_r) {
+ min_r = r;
+ min_pt = pts_count;
}
- fprintf(stderr, "\n");
- x0 = p[j + 5];
- y0 = p[j + 6];
- j += 7;
- break;
- default:
- assert(0);
+ pts_count++;
}
+ fprintf(stderr, "\n");
+
+ /* next segment start point is this segment end point */
+ x0 = x1;
+ y0 = y1;
}
fprintf(stderr, "pts_count %i, min_pt %i, min_r %.3f\n",
pts_count, min_pt, min_r);
+ /* render triangles */
unsigned int stop_count = state->linear_gradient_stop_count;
assert(2 <= stop_count);
unsigned int current_stop = 0;
b = min_pt == 0 ? pts_count - 1 : min_pt - 1;
while (a != b) {
float mean_r = (pts[t].r + pts[a].r + pts[b].r) / 3;
- fprintf(stderr, "triangle: t %i %.3f a %i %.3f b %i %.3f "
+ /*fprintf(stderr, "triangle: t %i %.3f a %i %.3f b %i %.3f "
"mean_r %.3f\n",
t, pts[t].r, a, pts[a].r, b, pts[b].r,
- mean_r);
+ mean_r);*/
while (current_stop != stop_count && current_stop_r < mean_r) {
current_stop++;
if (current_stop == stop_count)
}
shape->path = p;
shape->path_length = 7;
- shape->fill = svgtiny_TRANSPARENT;
+ shape->fill = svgtiny_TRANSPARENT;
shape->stroke = svgtiny_RGB(0xff, 0, 0);
state->diagram->shape_count++;
}
shape->text_y = state->ctm.b * pts[i].x +
state->ctm.d * pts[i].y + state->ctm.f;
shape->fill = svgtiny_RGB(0, 0, 0);
+ shape->stroke = svgtiny_TRANSPARENT;
state->diagram->shape_count++;
}
#endif
}
+/**
+ * Invert a transformation matrix.
+ */
+void svgtiny_invert_matrix(float *m, float *inv)
+{
+ float determinant = m[0]*m[3] - m[1]*m[2];
+ inv[0] = m[3] / determinant;
+ inv[1] = -m[1] / determinant;
+ inv[2] = -m[2] / determinant;
+ inv[3] = m[0] / determinant;
+ inv[4] = (m[2]*m[5] - m[3]*m[4]) / determinant;
+ inv[5] = (m[1]*m[4] - m[0]*m[5]) / determinant;
+}
+
+
/**
* Find an element in the document by id.
*/
projects / libsvgtiny.git / blobdiff