/**************************************************************************
*
* Copyright 2009 VMware, Inc. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
#include "stroker.h"
#include "path.h"
#include "vg_state.h"
#include "util_array.h"
#include "arc.h"
#include "bezier.h"
#include "matrix.h"
#include "path_utils.h"
#include "polygon.h"
#include "util/u_math.h"
#ifndef M_2PI
#define M_2PI 6.28318530717958647692528676655900576
#endif
#define STROKE_SEGMENTS 0
#define STROKE_DEBUG 0
#define DEBUG_EMITS 0
static const VGfloat curve_threshold = 0.25f;
static const VGfloat zero_coords[] = {0.f, 0.f};
enum intersection_type {
NoIntersections,
BoundedIntersection,
UnboundedIntersection,
};
enum line_join_mode {
FlatJoin,
SquareJoin,
MiterJoin,
RoundJoin,
RoundCap
};
struct stroke_iterator {
void (*next)(struct stroke_iterator *);
VGboolean (*has_next)(struct stroke_iterator *);
VGPathCommand (*current_command)(struct stroke_iterator *it);
void (*current_coords)(struct stroke_iterator *it, VGfloat *coords);
VGint position;
VGint coord_position;
const VGubyte *cmds;
const VGfloat *coords;
VGint num_commands;
VGint num_coords;
struct polygon *curve_poly;
VGint curve_index;
};
static VGPathCommand stroke_itr_command(struct stroke_iterator *itr)
{
return itr->current_command(itr);
}
static void stroke_itr_coords(struct stroke_iterator *itr, VGfloat *coords)
{
itr->current_coords(itr, coords);
}
static void stroke_fw_itr_coords(struct stroke_iterator *itr, VGfloat *coords)
{
if (itr->position >= itr->num_commands)
return;
switch (stroke_itr_command(itr)) {
case VG_MOVE_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
break;
case VG_LINE_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
break;
case VG_CUBIC_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
coords[2] = itr->coords[itr->coord_position + 2];
coords[3] = itr->coords[itr->coord_position + 3];
coords[4] = itr->coords[itr->coord_position + 4];
coords[5] = itr->coords[itr->coord_position + 5];
break;
default:
debug_assert(!"invalid command!\n");
}
}
static void stroke_bw_itr_coords(struct stroke_iterator *itr, VGfloat *coords)
{
if (itr->position >= itr->num_commands)
return;
switch (stroke_itr_command(itr)) {
case VG_MOVE_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
break;
case VG_LINE_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
break;
case VG_CUBIC_TO_ABS:
coords[0] = itr->coords[itr->coord_position + 4];
coords[1] = itr->coords[itr->coord_position + 5];
coords[2] = itr->coords[itr->coord_position + 2];
coords[3] = itr->coords[itr->coord_position + 3];
coords[4] = itr->coords[itr->coord_position + 0];
coords[5] = itr->coords[itr->coord_position + 1];
break;
default:
debug_assert(!"invalid command!\n");
}
}
static VGPathCommand stroke_fw_current_command(struct stroke_iterator *it)
{
return it->cmds[it->position];
}
static VGPathCommand stroke_bw_current_command(struct stroke_iterator *it)
{
VGPathCommand prev_cmd;
if (it->position == it->num_commands -1)
return VG_MOVE_TO_ABS;
prev_cmd = it->cmds[it->position + 1];
return prev_cmd;
}
static VGboolean stroke_fw_has_next(struct stroke_iterator *itr)
{
return itr->position < (itr->num_commands - 1);
}
static VGboolean stroke_bw_has_next(struct stroke_iterator *itr)
{
return itr->position > 0;
}
static void stroke_fw_next(struct stroke_iterator *itr)
{
VGubyte cmd;
debug_assert(stroke_fw_has_next(itr));
cmd = stroke_itr_command(itr);
itr->coord_position += num_elements_for_segments(&cmd, 1);
++itr->position;
}
static void stroke_bw_next(struct stroke_iterator *itr)
{
VGubyte cmd;
debug_assert(stroke_bw_has_next(itr));
--itr->position;
cmd = stroke_itr_command(itr);
itr->coord_position -= num_elements_for_segments(&cmd, 1);
}
static void stroke_itr_common_init(struct stroke_iterator *itr,
struct array *cmds,
struct array *coords)
{
itr->cmds = (VGubyte*)cmds->data;
itr->num_commands = cmds->num_elements;
itr->coords = (VGfloat*)coords->data;
itr->num_coords = coords->num_elements;
}
static void stroke_forward_iterator(struct stroke_iterator *itr,
struct array *cmds,
struct array *coords)
{
stroke_itr_common_init(itr, cmds, coords);
itr->position = 0;
itr->coord_position = 0;
itr->next = stroke_fw_next;
itr->has_next = stroke_fw_has_next;
itr->current_command = stroke_fw_current_command;
itr->current_coords = stroke_fw_itr_coords;
}
static void stroke_backward_iterator(struct stroke_iterator *itr,
struct array *cmds,
struct array *coords)
{
VGubyte cmd;
stroke_itr_common_init(itr, cmds, coords);
itr->position = itr->num_commands - 1;
cmd = stroke_bw_current_command(itr);
itr->coord_position = itr->num_coords -
num_elements_for_segments(&cmd, 1);
itr->next = stroke_bw_next;
itr->has_next = stroke_bw_has_next;
itr->current_command = stroke_bw_current_command;
itr->current_coords = stroke_bw_itr_coords;
}
static void stroke_flat_next(struct stroke_iterator *itr)
{
VGubyte cmd;
if (itr->curve_index >= 0) {
++itr->curve_index;
if (itr->curve_index >= polygon_vertex_count(itr->curve_poly)) {
itr->curve_index = -1;
polygon_destroy(itr->curve_poly);
itr->curve_poly = 0;
} else
return;
}
debug_assert(stroke_fw_has_next(itr));
cmd = itr->cmds[itr->position];
itr->coord_position += num_elements_for_segments(&cmd, 1);
++itr->position;
cmd = itr->cmds[itr->position];
if (cmd == VG_CUBIC_TO_ABS) {
struct bezier bezier;
VGfloat bez[8];
bez[0] = itr->coords[itr->coord_position - 2];
bez[1] = itr->coords[itr->coord_position - 1];
bez[2] = itr->coords[itr->coord_position];
bez[3] = itr->coords[itr->coord_position + 1];
bez[4] = itr->coords[itr->coord_position + 2];
bez[5] = itr->coords[itr->coord_position + 3];
bez[6] = itr->coords[itr->coord_position + 4];
bez[7] = itr->coords[itr->coord_position + 5];
bezier_init(&bezier,
bez[0], bez[1],
bez[2], bez[3],
bez[4], bez[5],
bez[6], bez[7]);
/* skip the first one, it's the same as the prev point */
itr->curve_index = 1;
if (itr->curve_poly) {
polygon_destroy(itr->curve_poly);
itr->curve_poly = 0;
}
itr->curve_poly = bezier_to_polygon(&bezier);
}
}
static VGboolean stroke_flat_has_next(struct stroke_iterator *itr)
{
return (itr->curve_index >= 0 &&
itr->curve_index < (polygon_vertex_count(itr->curve_poly)-1))
|| itr->position < (itr->num_commands - 1);
}
static VGPathCommand stroke_flat_current_command(struct stroke_iterator *it)
{
if (it->cmds[it->position] == VG_CUBIC_TO_ABS) {
return VG_LINE_TO_ABS;
}
return it->cmds[it->position];
}
static void stroke_flat_itr_coords(struct stroke_iterator *itr, VGfloat *coords)
{
if (itr->curve_index <= -1 && itr->position >= itr->num_commands)
return;
if (itr->curve_index >= 0) {
polygon_vertex(itr->curve_poly, itr->curve_index,
coords);
return;
}
switch (stroke_itr_command(itr)) {
case VG_MOVE_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
break;
case VG_LINE_TO_ABS:
coords[0] = itr->coords[itr->coord_position];
coords[1] = itr->coords[itr->coord_position + 1];
break;
case VG_CUBIC_TO_ABS:
default:
debug_assert(!"invalid command!\n");
}
}
static void stroke_flat_iterator(struct stroke_iterator *itr,
struct array *cmds,
struct array *coords)
{
stroke_itr_common_init(itr, cmds, coords);
itr->position = 0;
itr->coord_position = 0;
itr->next = stroke_flat_next;
itr->has_next = stroke_flat_has_next;
itr->current_command = stroke_flat_current_command;
itr->current_coords = stroke_flat_itr_coords;
itr->curve_index = -1;
itr->curve_poly = 0;
}
static INLINE VGboolean finite_coords4(const VGfloat *c)
{
return
isfinite(c[0]) && isfinite(c[1]) &&
isfinite(c[2]) && isfinite(c[3]);
}
/* from Graphics Gems II */
#define SAME_SIGNS(a, b) ((a) * (b) >= 0)
static VGboolean do_lines_intersect(VGfloat x1, VGfloat y1, VGfloat x2, VGfloat y2,
VGfloat x3, VGfloat y3, VGfloat x4, VGfloat y4)
{
VGfloat a1, a2, b1, b2, c1, c2; /* Coefficients of line eqns */
VGfloat r1, r2, r3, r4; /* 'sign' values */
a1 = y2 - y1;
b1 = x1 - x2;
c1 = x2 * y1 - x1 * y2;
r3 = a1 * x3 + b1 * y3 + c1;
r4 = a1 * x4 + b1 * y4 + c1;
if (r3 != 0 && r4 != 0 && SAME_SIGNS(r3, r4))
return VG_FALSE;
a2 = y4 - y3;
b2 = x3 - x4;
c2 = x4 * y3 - x3 * y4;
r1 = a2 * x1 + b2 * y1 + c2;
r2 = a2 * x2 + b2 * y2 + c2;
if (r1 != 0 && r2 != 0 && SAME_SIGNS(r1, r2))
return VG_FALSE;
return VG_TRUE;
}
static INLINE VGfloat line_dx(const VGfloat *l)
{
return l[2] - l[0];
}
static INLINE VGfloat line_dy(const VGfloat *l)
{
return l[3] - l[1];
}
static INLINE VGfloat line_angle(const VGfloat *l)
{
const VGfloat dx = line_dx(l);
const VGfloat dy = line_dy(l);
const VGfloat theta = atan2(-dy, dx) * 360.0 / M_2PI;
const VGfloat theta_normalized = theta < 0 ? theta + 360 : theta;
if (floatsEqual(theta_normalized, 360.f))
return 0;
else
return theta_normalized;
}
static INLINE void line_set_length(VGfloat *l, VGfloat len)
{
VGfloat uv[] = {l[0], l[1], l[2], l[3]};
if (null_line(l))
return;
line_normalize(uv);
l[2] = l[0] + line_dx(uv) * len;
l[3] = l[1] + line_dy(uv) * len;
}
static INLINE void line_translate(VGfloat *l, VGfloat x, VGfloat y)
{
l[0] += x;
l[1] += y;
l[2] += x;
l[3] += y;
}
static INLINE VGfloat line_angle_to(const VGfloat *l1,
const VGfloat *l2)
{
VGfloat a1, a2, delta, delta_normalized;
if (null_line(l1) || null_line(l1))
return 0;
a1 = line_angle(l1);
a2 = line_angle(l2);
delta = a2 - a1;
delta_normalized = delta < 0 ? delta + 360 : delta;
if (floatsEqual(delta, 360.f))
return 0;
else
return delta_normalized;
}
static INLINE VGfloat line_angles(const VGfloat *l1,
const VGfloat *l2)
{
VGfloat cos_line, rad = 0;
if (null_line(l1) || null_line(l2))
return 0;
cos_line = (line_dx(l1)*line_dx(l2) + line_dy(l1)*line_dy(l2)) /
(line_lengthv(l1)*line_lengthv(l2));
rad = 0;
if (cos_line >= -1.0 && cos_line <= 1.0)
rad = acos(cos_line);
return rad * 360 / M_2PI;
}
static INLINE VGfloat adapted_angle_on_x(const VGfloat *line)
{
const VGfloat identity[] = {0, 0, 1, 0};
VGfloat angle = line_angles(line, identity);
if (line_dy(line) > 0)
angle = 360 - angle;
return angle;
}
static enum intersection_type line_intersect(const VGfloat *l1,
const VGfloat *l2,
float *intersection_point)
{
VGfloat isect[2] = { 0 };
enum intersection_type type;
VGboolean dx_zero, ldx_zero;
if (null_line(l1) || null_line(l2) ||
!finite_coords4(l1) || !finite_coords4(l2))
return NoIntersections;
type = do_lines_intersect(l1[0], l1[1], l1[2], l1[3], l2[0], l2[1], l2[2], l2[3])
? BoundedIntersection : UnboundedIntersection;
dx_zero = floatsEqual(line_dx(l1) + 1, 1);
ldx_zero = floatsEqual(line_dx(l2) + 1, 1);
/* one of the lines is vertical */
if (dx_zero && ldx_zero) {
type = NoIntersections;
} else if (dx_zero) {
VGfloat la = line_dy(l2) / line_dx(l2);
isect[0] = l1[0];
isect[1] = la * l1[0] + l2[1] - la * l2[0];
} else if (ldx_zero) {
VGfloat ta = line_dy(l1) / line_dx(l1);
isect[0] = l2[0];
isect[1] = ta * l2[0] + l1[1] - ta*l1[0];
} else {
VGfloat x;
VGfloat ta = line_dy(l1) / line_dx(l1);
VGfloat la = line_dy(l2) / line_dx(l2);
if (ta == la)
return NoIntersections;
x = ( - l2[1] + la * l2[0] + l1[1] - ta * l1[0] ) / (la - ta);
isect[0] = x;
isect[1] = ta*(x - l1[0]) + l1[1];
}
if (intersection_point) {
intersection_point[0] = isect[0];
intersection_point[1] = isect[1];
}
return type;
}
static INLINE enum line_join_mode stroker_join_mode(struct stroker *s)
{
switch(s->join_style) {
case VG_JOIN_MITER:
return MiterJoin;
case VG_JOIN_ROUND:
return RoundJoin;
case VG_JOIN_BEVEL:
return FlatJoin;
default:
return FlatJoin;
}
}
static INLINE enum line_join_mode stroker_cap_mode(struct stroker *s)
{
switch(s->cap_style) {
case VG_CAP_BUTT:
return FlatJoin;
case VG_CAP_ROUND:
return RoundCap;
case VG_CAP_SQUARE:
return SquareJoin;
default:
return FlatJoin;
}
}
void stroker_emit_move_to(struct stroker *stroker, VGfloat x, VGfloat y)
{
VGubyte cmds = VG_MOVE_TO_ABS;
VGfloat coords[2] = {x, y};
#if DEBUG_EMITS
debug_printf("emit move %f, %f\n", x, y);
#endif
stroker->back2_x = stroker->back1_x;
stroker->back2_y = stroker->back1_y;
stroker->back1_x = x;
stroker->back1_y = y;
path_append_data(stroker->path,
1,
&cmds, &coords);
}
void stroker_emit_line_to(struct stroker *stroker, VGfloat x, VGfloat y)
{
VGubyte cmds = VG_LINE_TO_ABS;
VGfloat coords[2] = {x, y};
#if DEBUG_EMITS
debug_printf("emit line %f, %f\n", x, y);
#endif
stroker->back2_x = stroker->back1_x;
stroker->back2_y = stroker->back1_y;
stroker->back1_x = x;
stroker->back1_y = y;
path_append_data(stroker->path,
1,
&cmds, &coords);
}
void stroker_emit_curve_to(struct stroker *stroker, VGfloat px1, VGfloat py1,
VGfloat px2, VGfloat py2,
VGfloat x, VGfloat y)
{
VGubyte cmds = VG_CUBIC_TO_ABS;
VGfloat coords[6] = {px1, py1, px2, py2, x, y};
#if DEBUG_EMITS
debug_printf("emit curve %f, %f, %f, %f, %f, %f\n", px1, py1,
px2, py2, x, y);
#endif
if (px2 == x && py2 == y) {
if (px1 == x && py1 == y) {
stroker->back2_x = stroker->back1_x;
stroker->back2_y = stroker->back1_y;
} else {
stroker->back2_x = px1;
stroker->back2_y = py1;
}
} else {
stroker->back2_x = px2;
stroker->back2_y = py2;
}
stroker->back1_x = x;
stroker->back1_y = y;
path_append_data(stroker->path,
1,
&cmds, &coords);
}
static INLINE void create_round_join(struct stroker *stroker,
VGfloat x1, VGfloat y1,
VGfloat x2, VGfloat y2,
VGfloat width, VGfloat height)
{
struct arc arc;
struct matrix matrix;
matrix_load_identity(&matrix);
/*stroker_emit_line_to(stroker, nx, ny);*/
arc_init(&arc, VG_SCCWARC_TO,
x1, y1, x2, y2, width/2, height/2, 0);
arc_stroker_emit(&arc, stroker, &matrix);
}
static void create_joins(struct stroker *stroker,
VGfloat focal_x, VGfloat focal_y,
const VGfloat *next_line, enum line_join_mode join)
{
#if DEBUG_EMITS
debug_printf("create_joins: focal=[%f, %f], next_line=[%f, %f,%f, %f]\n",
focal_x, focal_y,
next_line[0], next_line[1], next_line[2], next_line[3]);
#endif
/* if we're alredy connected do nothing */
if (floatsEqual(stroker->back1_x, next_line[0]) &&
floatsEqual(stroker->back1_y, next_line[1]))
return;
if (join == FlatJoin) {
stroker_emit_line_to(stroker, next_line[0], next_line[1]);
} else {
VGfloat prev_line[] = {stroker->back2_x, stroker->back2_y,
stroker->back1_x, stroker->back1_y};
VGfloat isect[2] = { 0 };
enum intersection_type type = line_intersect(prev_line, next_line, isect);
if (join == SquareJoin) {
VGfloat offset = stroker->stroke_width / 2;
VGfloat l1[4] = {prev_line[0],
prev_line[1],
prev_line[2],
prev_line[3]};
VGfloat l2[4] = {next_line[2],
next_line[3],
next_line[0],
next_line[1]};
line_translate(l1, line_dx(l1), line_dy(l1));
line_set_length(l1, offset);
line_translate(l2, line_dx(l2), line_dy(l2));
line_set_length(l2, offset);
stroker_emit_line_to(stroker, l1[2], l1[3]);
stroker_emit_line_to(stroker, l2[2], l2[3]);
stroker_emit_line_to(stroker, l2[0], l2[1]);
} else if (join == RoundJoin) {
VGfloat offset = stroker->stroke_width / 2;
VGfloat short_cut[4] = {prev_line[2], prev_line[3],
next_line[0], next_line[1]};
VGfloat angle = line_angles(prev_line, short_cut);
if (type == BoundedIntersection ||
(angle > 90 && !floatsEqual(angle, 90.f))) {
stroker_emit_line_to(stroker, next_line[0], next_line[1]);
return;
}
create_round_join(stroker, prev_line[2], prev_line[3],
next_line[0], next_line[1],
offset * 2, offset * 2);
stroker_emit_line_to(stroker, next_line[0], next_line[1]);
} else if (join == RoundCap) {
VGfloat offset = stroker->stroke_width / 2;
VGfloat l1[4] = { prev_line[0], prev_line[1],
prev_line[2], prev_line[3] };
VGfloat l2[4] = {focal_x, focal_y,
prev_line[2], prev_line[3]};
line_translate(l1, line_dx(l1), line_dy(l1));
line_set_length(l1, KAPPA * offset);
/* normal between prev_line and focal */
line_translate(l2, -line_dy(l2), line_dx(l2));
line_set_length(l2, KAPPA * offset);
stroker_emit_curve_to(stroker, l1[2], l1[3],
l2[2], l2[3],
l2[0], l2[1]);
l2[0] = l2[0];
l2[1] = l2[1];
l2[2] = l2[0] - line_dx(l2);
l2[3] = l2[1] - line_dy(l2);
line_translate(l1, next_line[0] - l1[0], next_line[1] - l1[1]);
stroker_emit_curve_to(stroker,
l2[2], l2[3],
l1[2], l1[3],
l1[0], l1[1]);
} else if (join == MiterJoin) {
VGfloat miter_line[4] = {stroker->back1_x, stroker->back1_y,
isect[0], isect[1]};
VGfloat sl = (stroker->stroke_width * stroker->miter_limit);
VGfloat inside_line[4] = {prev_line[2], prev_line[3],
next_line[0], next_line[1]};
VGfloat angle = line_angle_to(inside_line, prev_line);
if (type == BoundedIntersection ||
(angle > 90 && !floatsEqual(angle, 90.f))) {
/*
debug_printf("f = %f, nl = %f, pl = %f, is = %f\n",
focal_x, next_line[0],
prev_line[2], isect[0]);*/
stroker_emit_line_to(stroker, next_line[0], next_line[1]);
return;
}
if (type == NoIntersections || line_lengthv(miter_line) > sl) {
stroker_emit_line_to(stroker, next_line[0], next_line[1]);
} else {
stroker_emit_line_to(stroker, isect[0], isect[1]);
stroker_emit_line_to(stroker, next_line[0], next_line[1]);
}
} else {
debug_assert(!"create_joins bad join style");
}
}
}
static void stroker_add_segment(struct stroker *stroker,
VGPathCommand cmd,
const VGfloat *coords,
VGint num_coords)
{
/* skip duplicated points */
if (stroker->segments->num_elements &&
stroker->last_cmd == cmd) {
VGfloat *data = stroker->control_points->data;
data += stroker->control_points->num_elements;
data -= num_coords;
switch (cmd) {
case VG_MOVE_TO_ABS:
if (floatsEqual(coords[0], data[0]) &&
floatsEqual(coords[1], data[1]))
return;
break;
case VG_LINE_TO_ABS:
if (floatsEqual(coords[0], data[0]) &&
floatsEqual(coords[1], data[1]))
return;
break;
case VG_CUBIC_TO_ABS:
if (floatsEqual(coords[0], data[0]) &&
floatsEqual(coords[1], data[1]) &&
floatsEqual(coords[2], data[2]) &&
floatsEqual(coords[3], data[3]) &&
floatsEqual(coords[4], data[4]) &&
floatsEqual(coords[5], data[5]))
return;
break;
default:
debug_assert(!"Invalid stroke segment");
}
} else if (stroker->last_cmd == VG_CUBIC_TO_ABS &&
cmd == VG_LINE_TO_ABS) {
VGfloat *data = stroker->control_points->data;
data += stroker->control_points->num_elements;
data -= 2;
if (floatsEqual(coords[0], data[0]) &&
floatsEqual(coords[1], data[1]))
return;
}
stroker->last_cmd = cmd;
array_append_data(stroker->segments, &cmd, 1);
array_append_data(stroker->control_points, coords, num_coords);
}
void stroker_move_to(struct stroker *stroker, VGfloat x, VGfloat y)
{
VGfloat coords[2] = {x, y};
#if STROKE_SEGMENTS
debug_printf("stroker_move_to(%f, %f)\n", x, y);
#endif
if (stroker->segments->num_elements > 0)
stroker->process_subpath(stroker);
array_reset(stroker->segments);
array_reset(stroker->control_points);
stroker_add_segment(stroker, VG_MOVE_TO_ABS, coords, 2);
}
void stroker_line_to(struct stroker *stroker, VGfloat x, VGfloat y)
{
VGfloat coords[] = {x, y};
#if STROKE_SEGMENTS
debug_printf("stroker_line_to(%f, %f)\n", x, y);
#endif
if (!stroker->segments->num_elements)
stroker_add_segment(stroker, VG_MOVE_TO_ABS, zero_coords, 2);
stroker_add_segment(stroker, VG_LINE_TO_ABS, coords, 2);
}
void stroker_curve_to(struct stroker *stroker, VGfloat px1, VGfloat py1,
VGfloat px2, VGfloat py2,
VGfloat x, VGfloat y)
{
VGfloat coords[] = {px1, py1,
px2, py2,
x, y};
#if STROKE_SEGMENTS
debug_printf("stroker_curve_to(%f, %f, %f, %f, %f, %f)\n",
px1, py1, px2, py2, x, y);
#endif
if (!stroker->segments->num_elements)
stroker_add_segment(stroker, VG_MOVE_TO_ABS, zero_coords, 2);
stroker_add_segment(stroker, VG_CUBIC_TO_ABS, coords, 6);
}
static INLINE VGboolean is_segment_null(VGPathCommand cmd,
VGfloat *coords,
VGfloat *res)
{
switch(cmd) {
case VG_MOVE_TO_ABS:
case VG_LINE_TO_ABS:
return floatsEqual(coords[0], res[0]) &&
floatsEqual(coords[1], res[1]);
break;
case VG_CUBIC_TO_ABS:
return floatsEqual(coords[0], res[0]) &&
floatsEqual(coords[1], res[1]) &&
floatsEqual(coords[2], res[0]) &&
floatsEqual(coords[3], res[1]) &&
floatsEqual(coords[4], res[0]) &&
floatsEqual(coords[5], res[1]);
break;
default:
assert(0);
}
return VG_FALSE;
}
static VGboolean vg_stroke_outline(struct stroke_iterator *it,
struct stroker *stroker,
VGboolean cap_first,
VGfloat *start_tangent)
{
#define MAX_OFFSET 16
struct bezier offset_curves[MAX_OFFSET];
VGPathCommand first_element;
VGfloat start[2], prev[2];
VGboolean first = VG_TRUE;
VGfloat offset;
first_element = stroke_itr_command(it);
if (first_element != VG_MOVE_TO_ABS) {
stroker_emit_move_to(stroker, 0.f, 0.f);
prev[0] = 0.f;
prev[1] = 0.f;
}
stroke_itr_coords(it, start);
#if STROKE_DEBUG
debug_printf(" -> (side) [%.2f, %.2f]\n",
start[0],
start[1]);
#endif
prev[0] = start[0];
prev[1] = start[1];
offset = stroker->stroke_width / 2;
if (!it->has_next(it)) {
/* single point */
return VG_TRUE;
}
while (it->has_next(it)) {
VGPathCommand cmd;
VGfloat coords[8];
it->next(it);
cmd = stroke_itr_command(it);
stroke_itr_coords(it, coords);
if (cmd == VG_LINE_TO_ABS) {
VGfloat line[4] = {prev[0], prev[1], coords[0], coords[1]};
VGfloat normal[4];
line_normal(line, normal);
#if STROKE_DEBUG
debug_printf("\n ---> (side) lineto [%.2f, %.2f]\n", coords[0], coords[1]);
#endif
line_set_length(normal, offset);
line_translate(line, line_dx(normal), line_dy(normal));
/* if we are starting a new subpath, move to correct starting point */
if (first) {
if (cap_first)
create_joins(stroker, prev[0], prev[1], line,
stroker_cap_mode(stroker));
else
stroker_emit_move_to(stroker, line[0], line[1]);
memcpy(start_tangent, line,
sizeof(VGfloat) * 4);
first = VG_FALSE;
} else {
create_joins(stroker, prev[0], prev[1], line,
stroker_join_mode(stroker));
}
/* add the stroke for this line */
stroker_emit_line_to(stroker, line[2], line[3]);
prev[0] = coords[0];
prev[1] = coords[1];
} else if (cmd == VG_CUBIC_TO_ABS) {
#if STROKE_DEBUG
debug_printf("\n ---> (side) cubicTo [%.2f, %.2f]\n",
coords[4],
coords[5]);
#endif
struct bezier bezier;
int count;
bezier_init(&bezier,
prev[0], prev[1], coords[0], coords[1],
coords[2], coords[3], coords[4], coords[5]);
count = bezier_translate_by_normal(&bezier,
offset_curves,
MAX_OFFSET,
offset,
curve_threshold);
if (count) {
/* if we are starting a new subpath, move to correct starting point */
VGfloat tangent[4];
VGint i;
bezier_start_tangent(&bezier, tangent);
line_translate(tangent,
offset_curves[0].x1 - bezier.x1,
offset_curves[0].y1 - bezier.y1);
if (first) {
VGfloat pt[2] = {offset_curves[0].x1,
offset_curves[0].y1};
if (cap_first) {
create_joins(stroker, prev[0], prev[1], tangent,
stroker_cap_mode(stroker));
} else {
stroker_emit_move_to(stroker, pt[0], pt[1]);
}
start_tangent[0] = tangent[0];
start_tangent[1] = tangent[1];
start_tangent[2] = tangent[2];
start_tangent[3] = tangent[3];
first = VG_FALSE;
} else {
create_joins(stroker, prev[0], prev[1], tangent,
stroker_join_mode(stroker));
}
/* add these beziers */
for (i = 0; i < count; ++i) {
struct bezier *bez = &offset_curves[i];
stroker_emit_curve_to(stroker,
bez->x2, bez->y2,
bez->x3, bez->y3,
bez->x4, bez->y4);
}
}
prev[0] = coords[4];
prev[1] = coords[5];
}
}
if (floatsEqual(start[0], prev[0]) &&
floatsEqual(start[1], prev[1])) {
/* closed subpath, join first and last point */
#if STROKE_DEBUG
debug_printf("\n stroker: closed subpath\n");
#endif
create_joins(stroker, prev[0], prev[1], start_tangent,
stroker_join_mode(stroker));
return VG_TRUE;
} else {
#if STROKE_DEBUG
debug_printf("\n stroker: open subpath\n");
#endif
return VG_FALSE;
}
#undef MAX_OFFSET
}
static void stroker_process_subpath(struct stroker *stroker)
{
VGboolean fwclosed, bwclosed;
VGfloat fw_start_tangent[4], bw_start_tangent[4];
struct stroke_iterator fwit;
struct stroke_iterator bwit;
debug_assert(stroker->segments->num_elements > 0);
memset(fw_start_tangent, 0,
sizeof(VGfloat)*4);
memset(bw_start_tangent, 0,
sizeof(VGfloat)*4);
stroke_forward_iterator(&fwit, stroker->segments,
stroker->control_points);
stroke_backward_iterator(&bwit, stroker->segments,
stroker->control_points);
debug_assert(fwit.cmds[0] == VG_MOVE_TO_ABS);
fwclosed = vg_stroke_outline(&fwit, stroker, VG_FALSE, fw_start_tangent);
bwclosed = vg_stroke_outline(&bwit, stroker, !fwclosed, bw_start_tangent);
if (!bwclosed)
create_joins(stroker,
fwit.coords[0], fwit.coords[1], fw_start_tangent,
stroker_cap_mode(stroker));
else {
/* hack to handle the requirement of the VG spec that says that strokes
* of len==0 that have butt cap or round cap still need
* to be rendered. (8.7.4 Stroke Generation) */
if (stroker->segments->num_elements <= 3) {
VGPathCommand cmd;
VGfloat data[8], coords[8];
struct stroke_iterator *it = &fwit;
stroke_forward_iterator(it, stroker->segments,
stroker->control_points);
cmd = stroke_itr_command(it);
stroke_itr_coords(it, coords);
if (cmd != VG_MOVE_TO_ABS) {
memset(data, 0, sizeof(VGfloat) * 8);
if (!is_segment_null(cmd, coords, data))
return;
} else {
data[0] = coords[0];
data[1] = coords[1];
}
while (it->has_next(it)) {
it->next(it);
cmd = stroke_itr_command(it);
stroke_itr_coords(it, coords);
if (!is_segment_null(cmd, coords, data))
return;
}
/* generate the square/round cap */
if (stroker->cap_style == VG_CAP_SQUARE) {
VGfloat offset = stroker->stroke_width / 2;
stroker_emit_move_to(stroker, data[0] - offset,
data[1] - offset);
stroker_emit_line_to(stroker, data[0] + offset,
data[1] - offset);
stroker_emit_line_to(stroker, data[0] + offset,
data[1] + offset);
stroker_emit_line_to(stroker, data[0] - offset,
data[1] + offset);
stroker_emit_line_to(stroker, data[0] - offset,
data[1] - offset);
} else if (stroker->cap_style == VG_CAP_ROUND) {
VGfloat offset = stroker->stroke_width / 2;
VGfloat cx = data[0], cy = data[1];
{ /*circle */
struct arc arc;
struct matrix matrix;
matrix_load_identity(&matrix);
stroker_emit_move_to(stroker, cx + offset, cy);
arc_init(&arc, VG_SCCWARC_TO,
cx + offset, cy,
cx - offset, cy,
offset, offset, 0);
arc_stroker_emit(&arc, stroker, &matrix);
arc_init(&arc, VG_SCCWARC_TO,
cx - offset, cy,
cx + offset, cy,
offset, offset, 0);
arc_stroker_emit(&arc, stroker, &matrix);
}
}
}
}
}
static INLINE VGfloat dash_pattern(struct dash_stroker *stroker,
VGint idx)
{
if (stroker->dash_pattern[idx] < 0)
return 0.f;
return stroker->dash_pattern[idx];
}
static void dash_stroker_process_subpath(struct stroker *str)
{
struct dash_stroker *stroker = (struct dash_stroker *)str;
VGfloat sum_length = 0;
VGint i;
VGint idash = 0;
VGfloat pos = 0;
VGfloat elen = 0;
VGfloat doffset = stroker->dash_phase;
VGfloat estart = 0;
VGfloat estop = 0;
VGfloat cline[4];
struct stroke_iterator it;
VGfloat prev[2];
VGfloat move_to_pos[2];
VGfloat line_to_pos[2];
VGboolean has_move_to = VG_FALSE;
stroke_flat_iterator(&it, stroker->base.segments,
stroker->base.control_points);
stroke_itr_coords(&it, prev);
move_to_pos[0] = prev[0];
move_to_pos[1] = prev[1];
debug_assert(stroker->dash_pattern_num > 0);
for (i = 0; i < stroker->dash_pattern_num; ++i) {
sum_length += dash_pattern(stroker, i);
}
if (floatIsZero(sum_length)) {
return;
}
doffset -= floorf(doffset / sum_length) * sum_length;
while (!floatIsZero(doffset) && doffset >= dash_pattern(stroker, idash)) {
doffset -= dash_pattern(stroker, idash);
idash = (idash + 1) % stroker->dash_pattern_num;
}
while (it.has_next(&it)) {
VGPathCommand cmd;
VGfloat coords[8];
VGboolean done;
it.next(&it);
cmd = stroke_itr_command(&it);
stroke_itr_coords(&it, coords);
debug_assert(cmd == VG_LINE_TO_ABS);
cline[0] = prev[0];
cline[1] = prev[1];
cline[2] = coords[0];
cline[3] = coords[1];
elen = line_lengthv(cline);
estop = estart + elen;
done = pos >= estop;
while (!done) {
VGfloat p2[2];
VGint idash_incr = 0;
VGboolean has_offset = doffset > 0;
VGfloat dpos = pos + dash_pattern(stroker, idash) - doffset - estart;
debug_assert(dpos >= 0);
if (dpos > elen) { /* dash extends this line */
doffset = dash_pattern(stroker, idash) - (dpos - elen);
pos = estop;
done = VG_TRUE;
p2[0] = cline[2];
p2[1] = cline[3];
} else { /* Dash is on this line */
line_point_at(cline, dpos/elen, p2);
pos = dpos + estart;
done = pos >= estop;
idash_incr = 1;
doffset = 0;
}
if (idash % 2 == 0) {
line_to_pos[0] = p2[0];
line_to_pos[1] = p2[1];
if (!has_offset || !has_move_to) {
stroker_move_to(&stroker->stroker, move_to_pos[0], move_to_pos[1]);
has_move_to = VG_TRUE;
}
stroker_line_to(&stroker->stroker, line_to_pos[0], line_to_pos[1]);
} else {
move_to_pos[0] = p2[0];
move_to_pos[1] = p2[1];
}
idash = (idash + idash_incr) % stroker->dash_pattern_num;
}
estart = estop;
prev[0] = coords[0];
prev[1] = coords[1];
}
if (it.curve_poly) {
polygon_destroy(it.curve_poly);
it.curve_poly = 0;
}
stroker->base.path = stroker->stroker.path;
}
static void default_begin(struct stroker *stroker)
{
array_reset(stroker->segments);
array_reset(stroker->control_points);
}
static void default_end(struct stroker *stroker)
{
if (stroker->segments->num_elements > 0)
stroker->process_subpath(stroker);
}
static void dash_stroker_begin(struct stroker *stroker)
{
struct dash_stroker *dasher =
(struct dash_stroker *)stroker;
default_begin(&dasher->stroker);
default_begin(stroker);
}
static void dash_stroker_end(struct stroker *stroker)
{
struct dash_stroker *dasher =
(struct dash_stroker *)stroker;
default_end(stroker);
default_end(&dasher->stroker);
}
void stroker_init(struct stroker *stroker,
struct vg_state *state)
{
stroker->stroke_width = state->stroke.line_width.f;
stroker->miter_limit = state->stroke.miter_limit.f;
stroker->cap_style = state->stroke.cap_style;
stroker->join_style = state->stroke.join_style;
stroker->begin = default_begin;
stroker->process_subpath = stroker_process_subpath;
stroker->end = default_end;
stroker->segments = array_create(sizeof(VGubyte));
stroker->control_points = array_create(sizeof(VGfloat));
stroker->back1_x = 0;
stroker->back1_y = 0;
stroker->back2_x = 0;
stroker->back2_y = 0;
stroker->path = path_create(VG_PATH_DATATYPE_F, 1.0f, 0.0f,
0, 0, VG_PATH_CAPABILITY_ALL);
/* Initialize with an invalid value */
stroker->last_cmd = (VGPathCommand)0;
}
void dash_stroker_init(struct stroker *str,
struct vg_state *state)
{
struct dash_stroker *stroker = (struct dash_stroker *)str;
int i;
stroker_init(str, state);
stroker_init(&stroker->stroker, state);
{
int real_num = state->stroke.dash_pattern_num;
if (real_num % 2)/* if odd, ignore the last one */
--real_num;
for (i = 0; i < real_num; ++i)
stroker->dash_pattern[i] = state->stroke.dash_pattern[i].f;
stroker->dash_pattern_num = real_num;
}
stroker->dash_phase = state->stroke.dash_phase.f;
stroker->dash_phase_reset = state->stroke.dash_phase_reset;
stroker->base.begin = dash_stroker_begin;
stroker->base.process_subpath = dash_stroker_process_subpath;
stroker->base.end = dash_stroker_end;
path_destroy(stroker->base.path);
stroker->base.path = NULL;
}
void stroker_begin(struct stroker *stroker)
{
stroker->begin(stroker);
}
void stroker_end(struct stroker *stroker)
{
stroker->end(stroker);
}
void stroker_cleanup(struct stroker *stroker)
{
array_destroy(stroker->segments);
array_destroy(stroker->control_points);
}
void dash_stroker_cleanup(struct dash_stroker *stroker)
{
/* if stroker->base.path is null means we never
* processed a valid path so delete the temp one
* we already created */
if (!stroker->base.path)
path_destroy(stroker->stroker.path);
stroker_cleanup(&stroker->stroker);
stroker_cleanup((struct stroker*)stroker);
}