void Canvas::draw_gridlines(const CairoCtx &cr) {
int spacing = VP_WIDTH / 20;
int hlines_count = VP_HEIGHT / spacing;
int vlines_count = VP_WIDTH / spacing;
int pos = VP_YMIN + spacing;
std::vector<double> dashes{5.0};
cr->save();
cr->set_dash(dashes, 0.0);
// Draw horizontal grid lines
for (int i = 0; i < hlines_count - 1; i++) {
cr->move_to(VP_XMIN, pos);
cr->line_to(VP_XMAX, pos);
pos += spacing;
}
// Draw vertical grid lines
pos = VP_XMIN + spacing;
for (int i = 0; i < vlines_count - 1; i++) {
cr->move_to(pos, VP_YMIN);
cr->line_to(pos, VP_YMAX);
pos += spacing;
}
cr->restore();
}
void Canvas::draw_center_lines(const CairoCtx &cr) {
// Coordinates for the center of the window
int xc = VP_XMIN + VP_WIDTH / 2;
int yc = VP_YMIN + VP_HEIGHT / 2;
// Set stroke properties for the centered axis
cr->set_line_width(1.0);
cr->set_source_rgba(0.0, 0.0, 0.0, 0.4); // Light gray
// Create horizontal and vertical axis centered on the screen
cr->move_to(VP_XMIN, yc);
cr->line_to(VP_XMAX, yc);
cr->move_to(xc, VP_YMIN);
cr->line_to(xc, VP_YMAX);
cr->stroke();
}
void BackLayer::render_page_borders(const Rect &bounds) {
CairoCtx *cr = _owner->cairoctx();
bool use_gl = _owner->has_gl();
double x, y;
double left, top;
double right, bottom;
Size psize = _owner->get_page_size();
double jitter = use_gl ? 0 : 0.5;
left = jitter;
right = bounds.right() + jitter;
top = jitter;
bottom = bounds.bottom() + jitter;
if (use_gl) {
glColor4d(0.75, 0.75, 0.75, 1);
glBegin(GL_LINES);
for (x = left; x <= right; x += psize.width) {
glVertex2d(x, top);
glVertex2d(x, bottom);
}
glEnd();
glBegin(GL_LINES);
for (y = top; y <= bottom; y += psize.height) {
glVertex2d(left, y);
glVertex2d(right, y);
}
glEnd();
} else {
cr->set_color(Color(0.75, 0.75, 0.75));
cr->set_line_width(1.0);
for (x = left; x <= right; x += psize.width) {
cr->move_to(x, top);
cr->line_to(x, bottom);
}
for (y = top; y <= bottom; y += psize.height) {
cr->move_to(left, y);
cr->line_to(right, y);
}
cr->stroke();
}
}
void Canvas::draw_viewport(const CairoCtx &cr) {
// Top horizontal line
cr->move_to(VP_XMIN, VP_YMIN);
cr->line_to(VP_XMAX, VP_YMIN);
// Right vertical line
cr->move_to(VP_XMAX, VP_YMIN);
cr->line_to(VP_XMAX, VP_YMAX);
// Bottom horizontal line
cr->move_to(VP_XMAX, VP_YMAX);
cr->line_to(VP_XMIN, VP_YMAX);
// Left vertical line
cr->move_to(VP_XMIN, VP_YMAX);
cr->line_to(VP_XMIN, VP_YMIN);
cr->stroke();
}
void BackLayer::render_grid(const Rect &bounds) {
bool use_gl = _owner->has_gl();
double gsize = _owner->_grid_size;
double x, y;
double left, top;
double right, bottom;
bool regen_display_lists = false;
float jitter = 0.5f; // use_gl ? 0 : 0.5f; Also for GL it renders sharper lines with 0.5 offset.
left = jitter;
right = bounds.right() + jitter;
top = jitter;
bottom = bounds.bottom() + jitter;
if (_grid1_dl == 0 || Point(left, top) != _grid_dl_start || _grid_dl_size != gsize || _grid_dl_area != bounds) {
_grid_dl_start = Point(left, top);
_grid_dl_size = gsize;
_grid_dl_area = bounds;
if (_grid1_dl == 0 && use_gl) {
_grid1_dl = glGenLists(1);
_grid2_dl = glGenLists(2);
}
regen_display_lists = true;
}
// Small grid.
if (gsize * _owner->get_zoom() > 4) {
if (use_gl) {
if (regen_display_lists) {
glNewList(_grid1_dl, GL_COMPILE);
glDisable(GL_TEXTURE_2D);
glColor4d(_line2_color.red, _line2_color.green, _line2_color.blue, _line2_color.alpha);
glBegin(GL_LINES);
for (x = left; x < right; x += gsize) {
glVertex2d(x, top);
glVertex2d(x, bottom);
}
glEnd();
glBegin(GL_LINES);
for (y = top; y < bottom; y += gsize) {
glVertex2d(left, y);
glVertex2d(right, y);
}
glEnd();
glEndList();
}
glCallList(_grid1_dl);
} else {
CairoCtx *cr = _owner->cairoctx();
cr->set_color(_line2_color);
cr->set_line_width(1.0);
for (x = left; x <= right; x += gsize) {
cr->move_to(x, top);
cr->line_to(x, bottom);
cr->stroke();
}
for (y = top; y <= bottom; y += gsize) {
cr->move_to(left, y);
cr->line_to(right, y);
cr->stroke();
}
cr->stroke();
}
}
gsize *= 8;
// Large grid.
if (gsize * _owner->get_zoom() >= 10) {
if (use_gl) {
if (regen_display_lists) {
glNewList(_grid2_dl, GL_COMPILE);
glDisable(GL_TEXTURE_2D);
glColor4d(_line1_color.red, _line1_color.green, _line1_color.blue, _line1_color.alpha);
glBegin(GL_LINES);
for (x = left; x < right; x += gsize) {
glVertex2d(x, top);
glVertex2d(x, bottom);
}
glEnd();
glBegin(GL_LINES);
for (y = top; y < bottom; y += gsize) {
glVertex2d(left, y);
glVertex2d(right, y);
}
glEnd();
glEndList();
}
glCallList(_grid2_dl);
} else {
CairoCtx *cr = _owner->cairoctx();
cr->set_color(_line1_color);
for (x = left; x <= right; x += gsize) {
cr->move_to(x, top);
cr->line_to(x, bottom);
cr->stroke();
}
for (y = top; y <= bottom; y += gsize) {
cr->move_to(left, y);
cr->line_to(right, y);
cr->stroke();
}
}
}
}