From 7b91fce804524d4f868f7f08fcbfc78402e0f59f Mon Sep 17 00:00:00 2001 From: James Bursa Date: Mon, 10 Mar 2008 04:43:44 +0000 Subject: Work on linearGradient attributes gradientUnits and gradientTransform. Adapt number of segment steps depending on difference in gradient. svn path=/trunk/libsvgtiny/; revision=3914 --- svgtiny.c | 138 ++++++++++++++++-------------- svgtiny_gradient.c | 242 ++++++++++++++++++++++++++++++++++++----------------- svgtiny_internal.h | 8 ++ 3 files changed, 249 insertions(+), 139 deletions(-) diff --git a/svgtiny.c b/svgtiny.c index 09c6bdd..10635ac 100644 --- a/svgtiny.c +++ b/svgtiny.c @@ -879,83 +879,93 @@ void svgtiny_parse_font_attributes(const xmlNode *node, void svgtiny_parse_transform_attributes(xmlNode *node, struct svgtiny_parse_state *state) { - char *transform, *s; + char *transform; + + /* parse transform */ + transform = (char *) xmlGetProp(node, (const xmlChar *) "transform"); + if (transform) { + svgtiny_parse_transform(transform, &state->ctm.a, &state->ctm.b, + &state->ctm.c, &state->ctm.d, + &state->ctm.e, &state->ctm.f); + xmlFree(transform); + } +} + + +/** + * Parse a transform string. + */ + +void svgtiny_parse_transform(char *s, float *ma, float *mb, + float *mc, float *md, float *me, float *mf) +{ float a, b, c, d, e, f; - float ctm_a, ctm_b, ctm_c, ctm_d, ctm_e, ctm_f; + float za, zb, zc, zd, ze, zf; float angle, x, y; int n; - /* parse transform */ - s = transform = (char *) xmlGetProp(node, - (const xmlChar *) "transform"); - if (transform) { - for (unsigned int i = 0; transform[i]; i++) - if (transform[i] == ',') - transform[i] = ' '; - - while (*s) { - a = d = 1; - b = c = 0; - e = f = 0; - if (sscanf(s, "matrix (%f %f %f %f %f %f) %n", + for (unsigned int i = 0; s[i]; i++) + if (s[i] == ',') + s[i] = ' '; + + while (*s) { + a = d = 1; + b = c = 0; + e = f = 0; + if (sscanf(s, "matrix (%f %f %f %f %f %f) %n", &a, &b, &c, &d, &e, &f, &n) == 6) - ; - else if (sscanf(s, "translate (%f %f) %n", + ; + else if (sscanf(s, "translate (%f %f) %n", &e, &f, &n) == 2) - ; - else if (sscanf(s, "translate (%f) %n", + ; + else if (sscanf(s, "translate (%f) %n", &e, &n) == 1) - ; - else if (sscanf(s, "scale (%f %f) %n", + ; + else if (sscanf(s, "scale (%f %f) %n", &a, &d, &n) == 2) - ; - else if (sscanf(s, "scale (%f) %n", + ; + else if (sscanf(s, "scale (%f) %n", &a, &n) == 1) - d = a; - else if (sscanf(s, "rotate (%f %f %f) %n", + d = a; + else if (sscanf(s, "rotate (%f %f %f) %n", &angle, &x, &y, &n) == 3) { - angle = angle / 180 * M_PI; - a = cos(angle); - b = sin(angle); - c = -sin(angle); - d = cos(angle); - e = -x * cos(angle) + y * sin(angle) + x; - f = -x * sin(angle) - y * cos(angle) + y; - } else if (sscanf(s, "rotate (%f) %n", + angle = angle / 180 * M_PI; + a = cos(angle); + b = sin(angle); + c = -sin(angle); + d = cos(angle); + e = -x * cos(angle) + y * sin(angle) + x; + f = -x * sin(angle) - y * cos(angle) + y; + } else if (sscanf(s, "rotate (%f) %n", &angle, &n) == 1) { - angle = angle / 180 * M_PI; - a = cos(angle); - b = sin(angle); - c = -sin(angle); - d = cos(angle); - } else if (sscanf(s, "skewX (%f) %n", + angle = angle / 180 * M_PI; + a = cos(angle); + b = sin(angle); + c = -sin(angle); + d = cos(angle); + } else if (sscanf(s, "skewX (%f) %n", &angle, &n) == 1) { - angle = angle / 180 * M_PI; - c = tan(angle); - } else if (sscanf(s, "skewY (%f) %n", + angle = angle / 180 * M_PI; + c = tan(angle); + } else if (sscanf(s, "skewY (%f) %n", &angle, &n) == 1) { - angle = angle / 180 * M_PI; - b = tan(angle); - } else - break; - ctm_a = state->ctm.a * a + state->ctm.c * b; - ctm_b = state->ctm.b * a + state->ctm.d * b; - ctm_c = state->ctm.a * c + state->ctm.c * d; - ctm_d = state->ctm.b * c + state->ctm.d * d; - ctm_e = state->ctm.a * e + state->ctm.c * f + - state->ctm.e; - ctm_f = state->ctm.b * e + state->ctm.d * f + - state->ctm.f; - state->ctm.a = ctm_a; - state->ctm.b = ctm_b; - state->ctm.c = ctm_c; - state->ctm.d = ctm_d; - state->ctm.e = ctm_e; - state->ctm.f = ctm_f; - s += n; - } - - xmlFree(transform); + angle = angle / 180 * M_PI; + b = tan(angle); + } else + break; + za = *ma * a + *mc * b; + zb = *mb * a + *md * b; + zc = *ma * c + *mc * d; + zd = *mb * c + *md * d; + ze = *ma * e + *mc * f + *me; + zf = *mb * e + *md * f + *mf; + *ma = za; + *mb = zb; + *mc = zc; + *md = zd; + *me = ze; + *mf = zf; + s += n; } } diff --git a/svgtiny_gradient.c b/svgtiny_gradient.c index c88c804..31dba1e 100644 --- a/svgtiny_gradient.c +++ b/svgtiny_gradient.c @@ -7,6 +7,7 @@ #define _GNU_SOURCE /* for strndup */ #include +#include #include #include "svgtiny.h" #include "svgtiny_internal.h" @@ -18,6 +19,7 @@ static svgtiny_code svgtiny_parse_linear_gradient(xmlNode *linear, 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); /** @@ -33,6 +35,13 @@ void svgtiny_find_gradient(const char *id, struct svgtiny_parse_state *state) 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); @@ -74,6 +83,25 @@ svgtiny_code svgtiny_parse_linear_gradient(xmlNode *linear, 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; @@ -170,14 +198,29 @@ svgtiny_code svgtiny_add_path_linear_gradient(float *p, unsigned int n, state->gradient_x2, state->gradient_y2); float gradient_x0, gradient_y0, gradient_x1, gradient_y1, gradient_dx, gradient_dy; - 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); + 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 @@ -227,9 +270,19 @@ svgtiny_code svgtiny_add_path_linear_gradient(float *p, unsigned int n, 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 { @@ -242,84 +295,107 @@ svgtiny_code svgtiny_add_path_linear_gradient(float *p, unsigned int n, 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; @@ -448,6 +524,7 @@ svgtiny_code svgtiny_add_path_linear_gradient(float *p, unsigned int n, 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 @@ -514,6 +591,21 @@ void svgtiny_path_bbox(float *p, unsigned int n, } +/** + * 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. */ diff --git a/svgtiny_internal.h b/svgtiny_internal.h index 84ecf5c..a729f25 100644 --- a/svgtiny_internal.h +++ b/svgtiny_internal.h @@ -8,6 +8,8 @@ #ifndef SVGTINY_INTERNAL_H #define SVGTINY_INTERNAL_H +#include + struct svgtiny_gradient_stop { float offset; svgtiny_colour color; @@ -39,6 +41,10 @@ struct svgtiny_parse_state { unsigned int linear_gradient_stop_count; const char *gradient_x1, *gradient_y1, *gradient_x2, *gradient_y2; struct svgtiny_gradient_stop gradient_stop[svgtiny_MAX_STOPS]; + bool gradient_user_space_on_use; + struct { + float a, b, c, d, e, f; + } gradient_transform; }; @@ -47,6 +53,8 @@ float svgtiny_parse_length(const char *s, int viewport_size, const struct svgtiny_parse_state state); void svgtiny_parse_color(const char *s, svgtiny_colour *c, struct svgtiny_parse_state *state); +void svgtiny_parse_transform(char *s, float *ma, float *mb, + float *mc, float *md, float *me, float *mf); struct svgtiny_shape *svgtiny_add_shape(struct svgtiny_parse_state *state); void svgtiny_transform_path(float *p, unsigned int n, struct svgtiny_parse_state *state); -- cgit v1.2.3