1 files changed, 59 insertions, 0 deletions
diff --git a/demos/ui.h b/demos/ui.h
new file mode 100644
index 0000000..9344e68
--- /dev/null
+++ b/demos/ui.h
@@ -0,0 +1,59 @@
+// License: CC0 / Public Domain
+#pragma once
+
+#define NK_INCLUDE_FIXED_TYPES
+#define NK_INCLUDE_DEFAULT_ALLOCATOR
+#define NK_INCLUDE_STANDARD_IO
+#define NK_INCLUDE_STANDARD_BOOL
+#define NK_INCLUDE_STANDARD_VARARGS
+#define NK_INCLUDE_VERTEX_BUFFER_OUTPUT
+#define NK_INCLUDE_FONT_BAKING
+#define NK_INCLUDE_DEFAULT_FONT
+#define NK_BUTTON_TRIGGER_ON_RELEASE
+#define NK_UINT_DRAW_INDEX
+#include <nuklear.h>
+
+#include "common.h"
+#include "window.h"
+
+struct ui;
+
+struct ui *ui_create(pl_gpu gpu);
+void ui_destroy(struct ui **ui);
+
+// Update/Logic/Draw cycle
+void ui_update_input(struct ui *ui, const struct window *window);
+struct nk_context *ui_get_context(struct ui *ui);
+bool ui_draw(struct ui *ui, const struct pl_swapchain_frame *frame);
+
+// Helper function to draw a custom widget for drag&drop operations, returns
+// true if the widget is hovered
+static inline bool ui_widget_hover(struct nk_context *nk, const char *label)
+{
+    struct nk_rect bounds;
+    if (!nk_widget(&bounds, nk))
+        return false;
+
+    struct nk_command_buffer *canvas = nk_window_get_canvas(nk);
+    bool hover = nk_input_is_mouse_hovering_rect(&nk->input, bounds);
+
+    float h, s, v;
+    nk_color_hsv_f(&h, &s, &v, nk->style.window.background);
+    struct nk_color background = nk_hsv_f(h, s, v + (hover ? 0.1f : -0.02f));
+    struct nk_color border = nk_hsv_f(h, s, v + 0.20f);
+    nk_fill_rect(canvas, bounds, 0.0f, background);
+    nk_stroke_rect(canvas, bounds, 0.0f, 2.0f, border);
+
+    const float pad = 10.0f;
+    struct nk_rect text = {
+        .x = bounds.x + pad,
+        .y = bounds.y + pad,
+        .w = bounds.w - 2 * pad,
+        .h = bounds.h - 2 * pad,
+    };
+
+    nk_draw_text(canvas, text, label, nk_strlen(label), nk->style.font,
+                 background, nk->style.text.color);
+
+    return hover;
+}