+
+struct ui_scrollbar
+{
+ int drag;
+ ui_px drag_offset;
+
+ ui_px py;
+ ui_px bar_height;
+ ui_px view_height;
+};
+
+static void ui_scrollbar( ui_ctx *ctx, struct ui_scrollbar *scrollbar, u32 id )
+{
+ scrollbar->view_height = ctx->cursor[3];
+
+ if( scrollbar->drag )
+ {
+ scrollbar->py = ctx->mouse[1]+scrollbar->drag_offset;
+ scrollbar->py = VG_MAX( scrollbar->py, 0 );
+ scrollbar->py = VG_MIN( scrollbar->py, ctx->cursor[3] - scrollbar->bar_height );
+
+ if( ctx->click_state == 0 || ctx->click_state == 3 )
+ scrollbar->drag = 0;
+ }
+
+ ui_new_node( ctx );
+ {
+ ui_fill_rect( ctx, ctx->cursor, ctx->colours_current->background );
+ ui_capture_mouse( ctx, id );
+
+ ctx->cursor[1] += scrollbar->py;
+ ctx->cursor[3] = scrollbar->bar_height;
+
+ ui_new_node( ctx );
+ {
+ ui_capture_mouse( ctx, __COUNTER__ );
+ struct ui_vert *drag_bar = ui_fill_rect( ctx, ctx->cursor, ctx->colours_current->bar );
+
+ if( ui_hasmouse( ctx ) || scrollbar->drag )
+ {
+ drag_bar[0].colour = ctx->colours_current->bar_hover;
+ drag_bar[1].colour = ctx->colours_current->bar_hover;
+ drag_bar[2].colour = ctx->colours_current->bar_hover;
+ drag_bar[3].colour = ctx->colours_current->bar_hover;
+
+ // start drag
+ if( ctx->click_state == 1 )
+ {
+ scrollbar->drag = 1;
+ scrollbar->drag_offset = scrollbar->py - ctx->mouse[1];
+ }
+ }
+ }
+ ui_end_down( ctx );
+ }
+ ui_end( ctx );
+}
+
+static ui_px ui_calculate_content_scroll( struct ui_scrollbar *scrollbar, ui_px content )
+{
+ float overlap = vg_maxf( 0.0f, (float)(content - scrollbar->view_height) );
+
+ float range = scrollbar->view_height - scrollbar->bar_height;
+ return ((float)scrollbar->py / range) * overlap;
+}
+
+static void ui_override_colours( ui_ctx *ctx, ui_colourset *set )
+{
+ ctx->colours_current = set;
+}
+
+static void ui_reset_colours( ui_ctx *ctx )
+{
+ ctx->colours_current = ctx->colours_main;
+ ctx->override_colour = 0xffffffff;
+}
+
+static void ui_push_image( ui_ctx *ctx, ui_rect rc, GLuint image )
+{
+ struct ui_image *img = &ctx->images[ ctx->image_count ++ ];
+ ui_rect_copy( rc, img->rc );
+ img->image = image;
+}
+
+// Shortnames
+#define gui_draw(...) ui_draw( &ui_global_ctx, __VA_ARGS__)
+#define gui_current(...) ui_current( &ui_global_ctx, __VA_ARGS__)
+#define gui_new_node() ui_new_node( &ui_global_ctx )
+#define gui_hasmouse(...) ui_hasmouse( &ui_global_ctx, __VA_ARGS__)
+#define gui_end() ui_end( &ui_global_ctx )
+#define gui_end_down() ui_end_down( &ui_global_ctx )
+#define gui_end_right() ui_end_right( &ui_global_ctx )
+#define gui_fill_y() ui_fill_y( &ui_global_ctx)
+#define gui_fill_x() ui_fill_x( &ui_global_ctx)
+#define gui_align_bottom() ui_align_bottom( &ui_global_ctx )
+#define gui_align_right() ui_align_right( &ui_global_ctx )
+#define gui_align_top() ui_align_top( &ui_global_ctx )
+#define gui_align_left() ui_align_left( &ui_global_ctx )
+#define gui_clamp_rect(...) ui_clamp_rect( &ui_global_ctx, __VA_ARGS__)
+#define gui_group_id(...) ui_group_id( &ui_global_ctx, __VA_ARGS__)
+#define gui_capture_mouse(...) ui_capture_mouse( &ui_global_ctx, __VA_ARGS__)
+#define gui_set_clip(...) ui_set_clip( &ui_global_ctx, __VA_ARGS__)
+#define gui_release_clip() ui_release_clip( &ui_global_ctx )
+#define gui_fill_rect_uv(...) ui_fill_rect_uv( &ui_global_ctx, __VA_ARGS__)
+#define gui_fill_rect(...) ui_fill_rect( &ui_global_ctx, __VA_ARGS__)
+#define gui_text(...) ui_text( &ui_global_ctx, __VA_ARGS__)
+#define gui_begin(...) ui_begin( &ui_global_ctx, __VA_ARGS__)
+#define gui_resolve(...) ui_resolve( &ui_global_ctx, __VA_ARGS__)
+#define gui_set_mouse(...) ui_set_mouse( &ui_global_ctx, __VA_ARGS__)
+#define gui_button(...) ui_button( &ui_global_ctx, __VA_ARGS__)
+#define gui_window(...) ui_window( &ui_global_ctx, __VA_ARGS__)
+#define gui_want_mouse() ui_want_mouse( &ui_global_ctx )
+#define gui_push_image(...) ui_push_image( &ui_global_ctx, __VA_ARGS__ )
+#define gui_scrollbar(...) ui_scrollbar( &ui_global_ctx, __VA_ARGS__)
+#define gui_override_colours(...) ui_override_colours( &ui_global_ctx, __VA_ARGS__)
+#define gui_reset_colours(...) ui_reset_colours( &ui_global_ctx )