564 lines
15 KiB
C++
564 lines
15 KiB
C++
#include "line_builder.h"
|
|
|
|
//----------------------------------------------------------------------------
|
|
// Util
|
|
//----------------------------------------------------------------------------
|
|
|
|
enum SegmentIntersectionResult {
|
|
SEGMENT_PARALLEL = 0,
|
|
SEGMENT_NO_INTERSECT = 1,
|
|
SEGMENT_INTERSECT = 2
|
|
};
|
|
|
|
static SegmentIntersectionResult segment_intersection(
|
|
Vector2 a, Vector2 b, Vector2 c, Vector2 d,
|
|
Vector2 * out_intersection)
|
|
{
|
|
// http://paulbourke.net/geometry/pointlineplane/ <-- Good stuff
|
|
Vector2 cd = d - c;
|
|
Vector2 ab = b - a;
|
|
float div = cd.y*ab.x - cd.x*ab.y;
|
|
|
|
if(Math::abs(div) > 0.001f) {
|
|
float ua = (cd.x * (a.y-c.y) - cd.y * (a.x-c.x)) / div;
|
|
float ub = (ab.x * (a.y-c.y) - ab.y * (a.x-c.x)) / div;
|
|
*out_intersection = a + ua * ab;
|
|
if(ua >= 0.f && ua <= 1.f &&
|
|
ub >= 0.f && ub <= 1.f)
|
|
return SEGMENT_INTERSECT;
|
|
return SEGMENT_NO_INTERSECT;
|
|
}
|
|
|
|
return SEGMENT_PARALLEL;
|
|
}
|
|
|
|
// TODO I'm pretty sure there is an even faster way to swap things
|
|
template <typename T>
|
|
static inline void swap(T & a, T & b) {
|
|
T tmp = a;
|
|
a = b;
|
|
b = tmp;
|
|
}
|
|
|
|
static float calculate_total_distance(const Vector<Vector2> & points) {
|
|
float d = 0.f;
|
|
for(int i = 1; i < points.size(); ++i) {
|
|
d += points[i].distance_to(points[i-1]);
|
|
}
|
|
return d;
|
|
}
|
|
|
|
static inline Vector2 rotate90(const Vector2 & v) {
|
|
// Note: the 2D referential is X-right, Y-down
|
|
return Vector2(v.y, -v.x);
|
|
}
|
|
|
|
static inline Vector2 interpolate(const Rect2 & r, const Vector2 & v) {
|
|
return Vector2(
|
|
Math::lerp(r.get_pos().x, r.get_pos().x + r.get_size().x, v.x),
|
|
Math::lerp(r.get_pos().y, r.get_pos().y + r.get_size().y, v.y)
|
|
);
|
|
}
|
|
|
|
//----------------------------------------------------------------------------
|
|
// LineBuilder
|
|
//----------------------------------------------------------------------------
|
|
|
|
LineBuilder::LineBuilder() {
|
|
joint_mode = LINE_JOINT_SHARP;
|
|
width = 10;
|
|
default_color = Color(0.4,0.5,1);
|
|
gradient = NULL;
|
|
sharp_limit = 2.f;
|
|
round_precision = 8;
|
|
begin_cap_mode = LINE_CAP_NONE;
|
|
end_cap_mode = LINE_CAP_NONE;
|
|
|
|
_interpolate_color = false;
|
|
_last_index[0] = 0;
|
|
_last_index[1] = 0;
|
|
}
|
|
|
|
|
|
void LineBuilder::clear_output() {
|
|
vertices.clear();
|
|
colors.clear();
|
|
indices.clear();
|
|
}
|
|
|
|
void LineBuilder::build() {
|
|
|
|
// Need at least 2 points to draw a line
|
|
if(points.size() < 2) {
|
|
clear_output();
|
|
return;
|
|
}
|
|
|
|
const float hw = width / 2.f;
|
|
const float hw_sq = hw*hw;
|
|
const float sharp_limit_sq = sharp_limit * sharp_limit;
|
|
const int len = points.size();
|
|
|
|
// Initial values
|
|
|
|
Vector2 pos0 = points[0];
|
|
Vector2 pos1 = points[1];
|
|
Vector2 f0 = (pos1 - pos0).normalized();
|
|
Vector2 u0 = rotate90(f0);
|
|
Vector2 pos_up0 = pos0 + u0 * hw;
|
|
Vector2 pos_down0 = pos0 - u0 * hw;
|
|
|
|
Color color0;
|
|
Color color1;
|
|
|
|
float current_distance0 = 0.f;
|
|
float current_distance1 = 0.f;
|
|
float total_distance;
|
|
_interpolate_color = gradient != NULL;
|
|
bool distance_required = _interpolate_color || texture_mode == LINE_TEXTURE_TILE;
|
|
if(distance_required)
|
|
total_distance = calculate_total_distance(points);
|
|
if(_interpolate_color)
|
|
color0 = gradient->get_color(0);
|
|
else
|
|
colors.push_back(default_color);
|
|
|
|
float uvx0 = 0.f;
|
|
float uvx1 = 0.f;
|
|
|
|
// Begin cap
|
|
if(begin_cap_mode == LINE_CAP_BOX) {
|
|
// Push back first vertices a little bit
|
|
pos_up0 -= f0 * hw;
|
|
pos_down0 -= f0 * hw;
|
|
// The line's outer length will be a little higher due to begin and end caps
|
|
total_distance += width;
|
|
current_distance0 += hw;
|
|
current_distance1 = current_distance0;
|
|
}
|
|
else if(begin_cap_mode == LINE_CAP_ROUND) {
|
|
if(texture_mode == LINE_TEXTURE_TILE) {
|
|
uvx0 = 0.5f;
|
|
}
|
|
new_arc(pos0, pos_up0 - pos0, -Math_PI, color0, Rect2(0.f, 0.f, 1.f, 1.f));
|
|
total_distance += width;
|
|
current_distance0 += hw;
|
|
current_distance1 = current_distance0;
|
|
}
|
|
|
|
strip_begin(pos_up0, pos_down0, color0, uvx0);
|
|
|
|
// pos_up0 ------------- pos_up1 --------------------
|
|
// | |
|
|
// pos0 - - - - - - - - - pos1 - - - - - - - - - pos2
|
|
// | |
|
|
// pos_down0 ------------ pos_down1 ------------------
|
|
//
|
|
// i-1 i i+1
|
|
|
|
// http://labs.hyperandroid.com/tag/opengl-lines
|
|
// (not the same implementation but visuals help a lot)
|
|
|
|
// For each additional segment
|
|
for(int i = 1; i < len-1; ++i) {
|
|
|
|
pos1 = points[i];
|
|
Vector2 pos2 = points[i+1];
|
|
|
|
Vector2 f1 = (pos2 - pos1).normalized();
|
|
Vector2 u1 = rotate90(f1);
|
|
|
|
// Determine joint orientation
|
|
const float dp = u0.dot(f1);
|
|
const Orientation orientation = (dp > 0.f ? UP : DOWN);
|
|
|
|
Vector2 inner_normal0, inner_normal1;
|
|
if(orientation == UP) {
|
|
inner_normal0 = u0 * hw;
|
|
inner_normal1 = u1 * hw;
|
|
}
|
|
else {
|
|
inner_normal0 = -u0 * hw;
|
|
inner_normal1 = -u1 * hw;
|
|
}
|
|
|
|
// ---------------------------
|
|
// /
|
|
// 0 / 1
|
|
// / /
|
|
// --------------------x------ /
|
|
// / / (here shown with orientation == DOWN)
|
|
// / /
|
|
// / /
|
|
// / /
|
|
// 2 /
|
|
// /
|
|
|
|
// Find inner intersection at the joint
|
|
Vector2 corner_pos_in, corner_pos_out;
|
|
SegmentIntersectionResult intersection_result = segment_intersection(
|
|
pos0 + inner_normal0, pos1 + inner_normal0,
|
|
pos1 + inner_normal1, pos2 + inner_normal1,
|
|
&corner_pos_in);
|
|
|
|
if(intersection_result == SEGMENT_INTERSECT)
|
|
// Inner parts of the segments intersect
|
|
corner_pos_out = 2.f * pos1 - corner_pos_in;
|
|
else {
|
|
// No intersection, segments are either parallel or too sharp
|
|
corner_pos_in = pos1 + inner_normal0;
|
|
corner_pos_out = pos1 - inner_normal0;
|
|
}
|
|
|
|
Vector2 corner_pos_up, corner_pos_down;
|
|
if(orientation == UP) {
|
|
corner_pos_up = corner_pos_in;
|
|
corner_pos_down = corner_pos_out;
|
|
}
|
|
else {
|
|
corner_pos_up = corner_pos_out;
|
|
corner_pos_down = corner_pos_in;
|
|
}
|
|
|
|
LineJointMode current_joint_mode = joint_mode;
|
|
|
|
Vector2 pos_up1, pos_down1;
|
|
if(intersection_result == SEGMENT_INTERSECT) {
|
|
// Fallback on bevel if sharp angle is too high (because it would produce very long miters)
|
|
if(current_joint_mode == LINE_JOINT_SHARP && corner_pos_out.distance_squared_to(pos1) / hw_sq > sharp_limit_sq) {
|
|
current_joint_mode = LINE_JOINT_BEVEL;
|
|
}
|
|
if(current_joint_mode == LINE_JOINT_SHARP) {
|
|
// In this case, we won't create joint geometry,
|
|
// The previous and next line quads will directly share an edge.
|
|
pos_up1 = corner_pos_up;
|
|
pos_down1 = corner_pos_down;
|
|
}
|
|
else {
|
|
// Bevel or round
|
|
if(orientation == UP) {
|
|
pos_up1 = corner_pos_up;
|
|
pos_down1 = pos1 - u0 * hw;
|
|
}
|
|
else {
|
|
pos_up1 = pos1 + u0 * hw;
|
|
pos_down1 = corner_pos_down;
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
// No intersection: fallback
|
|
pos_up1 = corner_pos_up;
|
|
pos_down1 = corner_pos_down;
|
|
}
|
|
|
|
// Add current line body quad
|
|
// Triangles are clockwise
|
|
if(distance_required) {
|
|
current_distance1 += pos0.distance_to(pos1);
|
|
}
|
|
if(_interpolate_color) {
|
|
color1 = gradient->get_color_at_offset(current_distance1 / total_distance);
|
|
}
|
|
if(texture_mode == LINE_TEXTURE_TILE) {
|
|
uvx0 = current_distance0 / width;
|
|
uvx1 = current_distance1 / width;
|
|
}
|
|
|
|
strip_add_quad(pos_up1, pos_down1, color1, uvx1);
|
|
|
|
// Swap vars for use in the next line
|
|
color0 = color1;
|
|
u0 = u1;
|
|
f0 = f1;
|
|
pos0 = pos1;
|
|
current_distance0 = current_distance1;
|
|
if(intersection_result == SEGMENT_INTERSECT) {
|
|
if(current_joint_mode == LINE_JOINT_SHARP) {
|
|
pos_up0 = pos_up1;
|
|
pos_down0 = pos_down1;
|
|
}
|
|
else {
|
|
if(orientation == UP) {
|
|
pos_up0 = corner_pos_up;
|
|
pos_down0 = pos1 - u1 * hw;
|
|
}
|
|
else {
|
|
pos_up0 = pos1 + u1 * hw;
|
|
pos_down0 = corner_pos_down;
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
pos_up0 = pos1 + u1 * hw;
|
|
pos_down0 = pos1 - u1 * hw;
|
|
}
|
|
// From this point, bu0 and bd0 concern the next segment
|
|
|
|
// Add joint geometry
|
|
if(current_joint_mode != LINE_JOINT_SHARP) {
|
|
|
|
// ________________ cbegin
|
|
// / \
|
|
// / \
|
|
// ____________/_ _ _\ cend
|
|
// | |
|
|
// | |
|
|
// | |
|
|
|
|
Vector2 cbegin, cend;
|
|
if(orientation == UP) {
|
|
cbegin = pos_down1;
|
|
cend = pos_down0;
|
|
}
|
|
else {
|
|
cbegin = pos_up1;
|
|
cend = pos_up0;
|
|
}
|
|
|
|
if(current_joint_mode == LINE_JOINT_BEVEL) {
|
|
strip_add_tri(cend, orientation);
|
|
}
|
|
else if(current_joint_mode == LINE_JOINT_ROUND) {
|
|
Vector2 vbegin = cbegin - pos1;
|
|
Vector2 vend = cend - pos1;
|
|
strip_add_arc(pos1, vend.angle_to(vbegin), orientation);
|
|
}
|
|
|
|
if(intersection_result != SEGMENT_INTERSECT)
|
|
// In this case the joint is too fucked up to be re-used,
|
|
// start again the strip with fallback points
|
|
strip_begin(pos_up0, pos_down0, color1, uvx1);
|
|
}
|
|
}
|
|
|
|
// Last (or only) segment
|
|
|
|
pos1 = points[points.size()-1];
|
|
|
|
Vector2 pos_up1 = pos1 + u0 * hw;
|
|
Vector2 pos_down1 = pos1 - u0 * hw;
|
|
|
|
// End cap (box)
|
|
if(end_cap_mode == LINE_CAP_BOX) {
|
|
pos_up1 += f0 * hw;
|
|
pos_down1 += f0 * hw;
|
|
}
|
|
|
|
if(distance_required) {
|
|
current_distance1 += pos0.distance_to(pos1);
|
|
}
|
|
if(_interpolate_color) {
|
|
color1 = gradient->get_color(gradient->get_points_count()-1);
|
|
}
|
|
if(texture_mode == LINE_TEXTURE_TILE) {
|
|
uvx1 = current_distance1 / width;
|
|
}
|
|
|
|
strip_add_quad(pos_up1, pos_down1, color1, uvx1);
|
|
|
|
// End cap (round)
|
|
if(end_cap_mode == LINE_CAP_ROUND) {
|
|
// Note: color is not used in case we don't interpolate...
|
|
Color color = _interpolate_color ? gradient->get_color(gradient->get_points_count()-1) : Color(0,0,0);
|
|
new_arc(pos1, pos_up1 - pos1, Math_PI, color, Rect2(uvx1-0.5f, 0.f, 1.f, 1.f));
|
|
}
|
|
}
|
|
|
|
void LineBuilder::strip_begin(Vector2 up, Vector2 down, Color color, float uvx) {
|
|
int vi = vertices.size();
|
|
|
|
vertices.push_back(up);
|
|
vertices.push_back(down);
|
|
|
|
if(_interpolate_color) {
|
|
colors.push_back(color);
|
|
colors.push_back(color);
|
|
}
|
|
|
|
if(texture_mode != LINE_TEXTURE_NONE) {
|
|
uvs.push_back(Vector2(uvx, 0.f));
|
|
uvs.push_back(Vector2(uvx, 1.f));
|
|
}
|
|
|
|
_last_index[UP] = vi;
|
|
_last_index[DOWN] = vi+1;
|
|
}
|
|
|
|
void LineBuilder::strip_new_quad(Vector2 up, Vector2 down, Color color, float uvx) {
|
|
int vi = vertices.size();
|
|
|
|
vertices.push_back(vertices[_last_index[UP]]);
|
|
vertices.push_back(vertices[_last_index[DOWN]]);
|
|
vertices.push_back(up);
|
|
vertices.push_back(down);
|
|
|
|
if(_interpolate_color) {
|
|
colors.push_back(color);
|
|
colors.push_back(color);
|
|
colors.push_back(color);
|
|
colors.push_back(color);
|
|
}
|
|
|
|
if(texture_mode != LINE_TEXTURE_NONE) {
|
|
uvs.push_back(uvs[_last_index[UP]]);
|
|
uvs.push_back(uvs[_last_index[DOWN]]);
|
|
uvs.push_back(Vector2(uvx, UP));
|
|
uvs.push_back(Vector2(uvx, DOWN));
|
|
}
|
|
|
|
indices.push_back(vi);
|
|
indices.push_back(vi+3);
|
|
indices.push_back(vi+1);
|
|
indices.push_back(vi);
|
|
indices.push_back(vi+2);
|
|
indices.push_back(vi+3);
|
|
|
|
_last_index[UP] = vi+2;
|
|
_last_index[DOWN] = vi+3;
|
|
}
|
|
|
|
void LineBuilder::strip_add_quad(Vector2 up, Vector2 down, Color color, float uvx) {
|
|
int vi = vertices.size();
|
|
|
|
vertices.push_back(up);
|
|
vertices.push_back(down);
|
|
|
|
if(_interpolate_color) {
|
|
colors.push_back(color);
|
|
colors.push_back(color);
|
|
}
|
|
|
|
if(texture_mode != LINE_TEXTURE_NONE) {
|
|
uvs.push_back(Vector2(uvx, 0.f));
|
|
uvs.push_back(Vector2(uvx, 1.f));
|
|
}
|
|
|
|
indices.push_back(_last_index[UP]);
|
|
indices.push_back(vi+1);
|
|
indices.push_back(_last_index[DOWN]);
|
|
indices.push_back(_last_index[UP]);
|
|
indices.push_back(vi);
|
|
indices.push_back(vi+1);
|
|
|
|
_last_index[UP] = vi;
|
|
_last_index[DOWN] = vi+1;
|
|
}
|
|
|
|
void LineBuilder::strip_add_tri(Vector2 up, Orientation orientation) {
|
|
int vi = vertices.size();
|
|
|
|
vertices.push_back(up);
|
|
|
|
if(_interpolate_color) {
|
|
colors.push_back(colors[colors.size()-1]);
|
|
}
|
|
|
|
Orientation opposite_orientation = orientation == UP ? DOWN : UP;
|
|
|
|
if(texture_mode != LINE_TEXTURE_NONE) {
|
|
// UVs are just one slice of the texture all along
|
|
// (otherwise we can't share the bottom vertice)
|
|
uvs.push_back(uvs[_last_index[opposite_orientation]]);
|
|
}
|
|
|
|
indices.push_back(_last_index[opposite_orientation]);
|
|
indices.push_back(vi);
|
|
indices.push_back(_last_index[orientation]);
|
|
|
|
_last_index[opposite_orientation] = vi;
|
|
}
|
|
|
|
void LineBuilder::strip_add_arc(Vector2 center, float angle_delta, Orientation orientation) {
|
|
|
|
// Take the two last vertices and extrude an arc made of triangles
|
|
// that all share one of the initial vertices
|
|
|
|
Orientation opposite_orientation = orientation == UP ? DOWN : UP;
|
|
Vector2 vbegin = vertices[_last_index[opposite_orientation]] - center;
|
|
float radius = vbegin.length();
|
|
float angle_step = Math_PI / static_cast<float>(round_precision);
|
|
float steps = Math::abs(angle_delta) / angle_step;
|
|
|
|
if(angle_delta < 0.f)
|
|
angle_step = -angle_step;
|
|
|
|
float t = vbegin.angle_to(Vector2(1, 0));
|
|
float end_angle = t + angle_delta;
|
|
Vector2 rpos(0,0);
|
|
|
|
// Arc vertices
|
|
for(int ti = 0; ti < steps; ++ti, t += angle_step) {
|
|
rpos = center + Vector2(Math::cos(t), Math::sin(t)) * radius;
|
|
strip_add_tri(rpos, orientation);
|
|
}
|
|
|
|
// Last arc vertice
|
|
rpos = center + Vector2(Math::cos(end_angle), Math::sin(end_angle)) * radius;
|
|
strip_add_tri(rpos, orientation);
|
|
}
|
|
|
|
void LineBuilder::new_arc(Vector2 center, Vector2 vbegin, float angle_delta, Color color, Rect2 uv_rect) {
|
|
|
|
// Make a standalone arc that doesn't use existing vertices,
|
|
// with undistorted UVs from withing a square section
|
|
|
|
float radius = vbegin.length();
|
|
float angle_step = Math_PI / static_cast<float>(round_precision);
|
|
float steps = Math::abs(angle_delta) / angle_step;
|
|
|
|
if(angle_delta < 0.f)
|
|
angle_step = -angle_step;
|
|
|
|
float t = vbegin.angle_to(Vector2(1, 0));
|
|
float end_angle = t + angle_delta;
|
|
Vector2 rpos(0,0);
|
|
float tt_begin = -Math_PI / 2.f;
|
|
float tt = tt_begin;
|
|
|
|
// Center vertice
|
|
int vi = vertices.size();
|
|
vertices.push_back(center);
|
|
if(_interpolate_color)
|
|
colors.push_back(color);
|
|
if(texture_mode != LINE_TEXTURE_NONE)
|
|
uvs.push_back(interpolate(uv_rect, Vector2(0.5f, 0.5f)));
|
|
|
|
// Arc vertices
|
|
for(int ti = 0; ti < steps; ++ti, t += angle_step) {
|
|
Vector2 sc = Vector2(Math::cos(t), Math::sin(t));
|
|
rpos = center + sc * radius;
|
|
|
|
vertices.push_back(rpos);
|
|
if(_interpolate_color)
|
|
colors.push_back(color);
|
|
if(texture_mode != LINE_TEXTURE_NONE) {
|
|
Vector2 tsc = Vector2(Math::cos(tt), Math::sin(tt));
|
|
uvs.push_back(interpolate(uv_rect, 0.5f*(tsc+Vector2(1.f,1.f))));
|
|
tt += angle_step;
|
|
}
|
|
}
|
|
|
|
// Last arc vertice
|
|
Vector2 sc = Vector2(Math::cos(end_angle), Math::sin(end_angle));
|
|
rpos = center + sc * radius;
|
|
vertices.push_back(rpos);
|
|
if(_interpolate_color)
|
|
colors.push_back(color);
|
|
if(texture_mode != LINE_TEXTURE_NONE) {
|
|
tt = tt_begin + angle_delta;
|
|
Vector2 tsc = Vector2(Math::cos(tt), Math::sin(tt));
|
|
uvs.push_back(interpolate(uv_rect, 0.5f*(tsc+Vector2(1.f,1.f))));
|
|
}
|
|
|
|
// Make up triangles
|
|
int vi0 = vi;
|
|
for(int ti = 0; ti < steps; ++ti) {
|
|
indices.push_back(vi0);
|
|
indices.push_back(++vi);
|
|
indices.push_back(vi+1);
|
|
}
|
|
}
|
|
|
|
|