static void
interpolate_color(struct nk_color c1, struct nk_color c2, struct nk_color *result, float fraction)
{
float r = c1.r + (c2.r - c1.r) * fraction;
float g = c1.g + (c2.g - c1.g) * fraction;
float b = c1.b + (c2.b - c1.b) * fraction;
float a = c1.a + (c2.a - c1.a) * fraction;
result->r = (nk_byte)NK_CLAMP(0, r, 255);
result->g = (nk_byte)NK_CLAMP(0, g, 255);
result->b = (nk_byte)NK_CLAMP(0, b, 255);
result->a = (nk_byte)NK_CLAMP(0, a, 255);
}
/* ===============================================================
*
* SCROLLBAR
*
* ===============================================================*/
NK_LIB float
nk_scrollbar_behavior(nk_flags *state, struct nk_input *in,
int has_scrolling, const struct nk_rect *scroll,
const struct nk_rect *cursor, const struct nk_rect *empty0,
const struct nk_rect *empty1, float scroll_offset,
float target, float scroll_step, enum nk_orientation o)
{
nk_flags ws = 0;
int left_mouse_down;
int left_mouse_clicked;
int left_mouse_click_in_cursor;
float scroll_delta;
nk_widget_state_reset(state);
if (!in) return scroll_offset;
left_mouse_down = in->mouse.buttons[NK_BUTTON_LEFT].down;
left_mouse_clicked = in->mouse.buttons[NK_BUTTON_LEFT].clicked;
left_mouse_click_in_cursor = nk_input_has_mouse_click_down_in_rect(in,
NK_BUTTON_LEFT, *cursor, nk_true);
if (nk_input_is_mouse_hovering_rect(in, *scroll))
*state = NK_WIDGET_STATE_HOVERED;
scroll_delta = (o == NK_VERTICAL) ? in->mouse.scroll_delta.y: in->mouse.scroll_delta.x;
if (left_mouse_down && left_mouse_click_in_cursor && !left_mouse_clicked) {
/* update cursor by mouse dragging */
float pixel, delta;
*state = NK_WIDGET_STATE_ACTIVE;
if (o == NK_VERTICAL) {
float cursor_y;
pixel = in->mouse.delta.y;
delta = (pixel / scroll->h) * target;
scroll_offset = NK_CLAMP(0, scroll_offset + delta, target - scroll->h);
cursor_y = scroll->y + ((scroll_offset/target) * scroll->h);
in->mouse.buttons[NK_BUTTON_LEFT].clicked_pos.y = cursor_y + cursor->h/2.0f;
} else {
float cursor_x;
pixel = in->mouse.delta.x;
delta = (pixel / scroll->w) * target;
scroll_offset = NK_CLAMP(0, scroll_offset + delta, target - scroll->w);
cursor_x = scroll->x + ((scroll_offset/target) * scroll->w);
in->mouse.buttons[NK_BUTTON_LEFT].clicked_pos.x = cursor_x + cursor->w/2.0f;
}
} else if ((nk_input_is_key_pressed(in, NK_KEY_SCROLL_UP) && o == NK_VERTICAL && has_scrolling)||
nk_button_behavior(&ws, *empty0, in, NK_BUTTON_DEFAULT)) {
/* scroll page up by click on empty space or shortcut */
if (o == NK_VERTICAL)
scroll_offset = NK_MAX(0, scroll_offset - scroll->h);
else scroll_offset = NK_MAX(0, scroll_offset - scroll->w);
} else if ((nk_input_is_key_pressed(in, NK_KEY_SCROLL_DOWN) && o == NK_VERTICAL && has_scrolling) ||
nk_button_behavior(&ws, *empty1, in, NK_BUTTON_DEFAULT)) {
/* scroll page down by click on empty space or shortcut */
if (o == NK_VERTICAL)
scroll_offset = NK_MIN(scroll_offset + scroll->h, target - scroll->h);
else scroll_offset = NK_MIN(scroll_offset + scroll->w, target - scroll->w);
} else if (has_scrolling) {
if ((scroll_delta < 0 || (scroll_delta > 0))) {
/* update cursor by mouse scrolling */
scroll_offset = scroll_offset + scroll_step * (-scroll_delta);
if (o == NK_VERTICAL)
scroll_offset = NK_CLAMP(0, scroll_offset, target - scroll->h);
else scroll_offset = NK_CLAMP(0, scroll_offset, target - scroll->w);
} else if (nk_input_is_key_pressed(in, NK_KEY_SCROLL_START)) {
/* update cursor to the beginning */
if (o == NK_VERTICAL) scroll_offset = 0;
} else if (nk_input_is_key_pressed(in, NK_KEY_SCROLL_END)) {
/* update cursor to the end */
if (o == NK_VERTICAL) scroll_offset = target - scroll->h;
}
}
if (*state & NK_WIDGET_STATE_HOVER && !nk_input_is_mouse_prev_hovering_rect(in, *scroll))
*state |= NK_WIDGET_STATE_ENTERED;
else if (nk_input_is_mouse_prev_hovering_rect(in, *scroll))
*state |= NK_WIDGET_STATE_LEFT;
return scroll_offset;
}
NK_LIB float
nk_do_scrollbarh(nk_flags *state,
struct nk_command_buffer *out, struct nk_rect scroll, int has_scrolling,
float offset, float target, float step, float button_pixel_inc,
const struct nk_style_scrollbar *style, struct nk_input *in,
const struct nk_user_font *font)
{
struct nk_rect cursor;
struct nk_rect empty_west;
struct nk_rect empty_east;
float scroll_step;
float scroll_offset;
float scroll_off;
float scroll_ratio;
NK_ASSERT(out);
NK_ASSERT(style);
if (!out || !style) return 0;
/* scrollbar background */
scroll.h = NK_MAX(scroll.h, 1);
scroll.w = NK_MAX(scroll.w, 2 * scroll.h);
if (target <= scroll.w) return 0;
/* optional scrollbar buttons */
if (style->show_buttons) {
nk_flags ws;
float scroll_w;
struct nk_rect button;
button.y = scroll.y;
button.w = scroll.h;
button.h = scroll.h;
scroll_w = scroll.w - 2 * button.w;
scroll_step = NK_MIN(step, button_pixel_inc);
/* decrement button */
button.x = scroll.x;
if (nk_do_button_symbol(&ws, out, button, style->dec_symbol,
NK_BUTTON_REPEATER, &style->dec_button, in, font))
offset = offset - scroll_step;
/* increment button */
button.x = scroll.x + scroll.w - button.w;
if (nk_do_button_symbol(&ws, out, button, style->inc_symbol,
NK_BUTTON_REPEATER, &style->inc_button, in, font))
offset = offset + scroll_step;
scroll.x = scroll.x + button.w;
scroll.w = scroll_w;
}
/* calculate scrollbar constants */
scroll_step = NK_MIN(step, scroll.w);
scroll_offset = NK_CLAMP(0, offset, target - scroll.w);
scroll_ratio = scroll.w / target;
scroll_off = scroll_offset / target;
/* calculate cursor bounds */
cursor.w = (scroll_ratio * scroll.w) - (2*style->border + 2*style->padding.x);
cursor.x = scroll.x + (scroll_off * scroll.w) + style->border + style->padding.x;
cursor.h = scroll.h - (2 * style->border + 2 * style->padding.y);
cursor.y = scroll.y + style->border + style->padding.y;
/* calculate empty space around cursor */
empty_west.x = scroll.x;
empty_west.y = scroll.y;
empty_west.w = cursor.x - scroll.x;
empty_west.h = scroll.h;
empty_east.x = cursor.x + cursor.w;
empty_east.y = scroll.y;
empty_east.w = (scroll.x + scroll.w) - (cursor.x + cursor.w);
empty_east.h = scroll.h;
/* update scrollbar */
scroll_offset = nk_scrollbar_behavior(state, in, has_scrolling, &scroll, &cursor,
&empty_west, &empty_east, scroll_offset, target, scroll_step, NK_HORIZONTAL);
scroll_off = scroll_offset / target;
cursor.x = scroll.x + (scroll_off * scroll.w);
/* draw scrollbar */
if (style->draw_begin) style->draw_begin(out, style->userdata);
nk_draw_scrollbar(out, *state, style, &scroll, &cursor);
if (style->draw_end) style->draw_end(out, style->userdata);
return scroll_offset;
}
