unified ui padding

src/base/base.h

@@ -378,6 +378,7 @@ void __asan_unpoison_memory_region(void const volatile *add, size_t);
 #define Color_Yellow    Rgb32(0xFF, 0xFF, 0x00)
 #define Color_Orange    Rgb32(0xFF, 0xA5, 0x00)
 #define Color_Purple    Rgb32(0xFF, 0x00, 0XFF)
+#define Color_Cyan      Rgb32(0x00, 0xFF, 0XFF)
 
 ////////////////////////////////////////////////////////////
 //~ Intrinsic headers

src/config.h

@@ -72,8 +72,6 @@
 #define GPU_DEBUG 1
 #define GPU_DEBUG_VALIDATION 0
 
-#define UI_DEBUG 0
-
 /* If virtual fibers are enabled, each fiber will get its own OS thread,
  * and fiber suspend/resume will be emulated using OS thread primitives.
  * This is slow but allows for easier debugging in tricky cases

src/pp/pp.c

@@ -394,7 +394,13 @@ void PP_UpdateUser(void)
     g->screen_size.y = MaxI32(g->screen_size.y, 1);
 
     //- Begin UI
-    UI_BeginBuild(controller_events);
+    UI_BuildFlag ui_build_flags = 0;
+    if (g->ui_debug)
+    {
+        ui_build_flags |= UI_BuildFlag_Debug;
+    }
+
+    UI_BeginBuild(controller_events, ui_build_flags);
     UI_Push(LayoutAxis, Axis_Y);
     if (window_frame.forced_top)
     {
@@ -676,6 +682,11 @@ void PP_UpdateUser(void)
         g->debug_camera = !g->debug_camera;
     }
 
+    if (g->bind_states[PP_BindKind_DebugUi].num_presses > 0)
+    {
+        g->ui_debug = !g->ui_debug;
+    }
+
     if (g->bind_states[PP_BindKind_DebugLister].num_presses > 0)
     {
         g->lister_active = !g->lister_active;
@@ -1953,22 +1964,28 @@ void PP_UpdateUser(void)
             UI_Push(BorderColor, Rgba32F(0.2, 0.2, 0.2, 1));
             UI_Push(Border, 2);
 
-            UI_SetNext(FloatingPos, g->lister_pos);
+            // UI_Size padding = UI_FILL(1, 0);
-            UI_SetNext(LayoutAxis, Axis_Y);
+            // UI_Size padding = UI_PIX(10, 0);
-            UI_SetNext(Rounding, UI_RPIX(10));
+            UI_Push(Width, UI_PIX(size.x, 0));
+            UI_Push(Height, UI_PIX(size.y, 0));
+
+            UI_Push(LayoutAxis, Axis_Y);
+            UI_Push(FloatingPos, g->lister_pos);
             UI_SetNext(Flags, UI_BoxFlag_Floating);
-            UI_SetNext(Width, UI_PIX(size.x, 0));
+            UI_SetNext(Rounding, UI_RPIX(50));
-            UI_SetNext(Height, UI_PIX(size.y, 0));
             UI_Box *lister_box = UI_BuildBox(Lit("lister"));
-            UI_PushCP(lister_box);
+            UI_Box *lister_pad = lister_box;
+            UI_PushCP(lister_pad);
             {
-                UI_Push(BackgroundColor, 0);
                 // UI_BuildSpacer(UI_PIX(10, 0));
+                UI_Push(BackgroundColor, 0);
+                UI_Push(LayoutAxis, Axis_X);
+                UI_Push(Width, UI_FILL(1, 0));
+                UI_Push(Height, UI_FNT(5, 0));
                 {
-                    UI_SetNext(LayoutAxis, Axis_X);
+                    UI_Push(BackgroundColor, Color_Orange);
-                    UI_SetNext(Width, UI_FILL(1, 0));
+                    UI_Push(Border, 2);
-                    UI_SetNext(Height, UI_FNT(1, 0));
+
-                    // UI_SetNext(Border, 0);
                     UI_Box *title_bar = UI_BuildBox(Zstr);
                     UI_PushCP(title_bar);
                     {
@@ -1976,19 +1993,27 @@ void PP_UpdateUser(void)
                         UI_Push(Padding, 0);
                         UI_Push(BackgroundColor, 0);
                         UI_Push(Border, 0);
-                        {
+
-                            UI_Box *left_box = UI_BuildBox(Zstr);
+                        UI_Box *left_box = UI_BuildBox(Zstr);
-                        }
+                        // UI_SetNext(LeftPadding, UI_PIX(10, 1));
+                        // UI_SetNext(Padding, UI_PAD(UI_FILL(1, 0)));
+                        UI_Box *center_box = UI_BuildBox(Zstr);
+                        UI_Box *right_box = UI_BuildBox(Zstr);
+
+                        // UI_Pad title_padding = UI_PADEX(.left = UI_PIX(50, 0), .right = UI_PIX(50, 0), .bottom = UI_PIX(10, 0));
+                        // UI_Pad title_padding = UI_PAD(UI_FILL(1, 0));
+                        // UI_Box *center_pad = UI_BuildPad(center_box, title_padding);
+                        // UI_Box *center_pad = center_box;
+                        UI_PushCP(center_box);
                         {
                             UI_SetNext(Text, Lit("Title"));
                             UI_SetNext(Flags, UI_BoxFlag_DrawText);
-                            UI_SetNext(Width, UI_FIT(1));
+                            // UI_SetNext(Padding, UI_PADEX(.left = UI_PIX(100, 0), .right = UI_PIX(50, 0), .bottom = UI_PIX(10, 0)));
+                            // UI_SetNext(Padding, UI_PADEX(.left = UI_PIX(1, 0)));
+                            UI_SetNext(Padding, UI_PADALL(UI_FILL(1, 0)));
                             UI_Box *title_box = UI_BuildBox(Zstr);
                         }
-                        {
+                        UI_PopCP();
-                            UI_Box *right_box = UI_BuildBox(Zstr);
-
-                        }
                     }
                     UI_PopCP();
                 }
@@ -2017,7 +2042,7 @@ void PP_UpdateUser(void)
         {
             UI_Push(BackgroundColor, 0);
             UI_Push(BorderColor, 0);
-            UI_Push(Padding, 2);
+            // UI_Push(Padding, UI_PIX(5, 0));
 
             UI_BuildLabelF("Blended world entities:             %F/%F", FmtUint(g->ss_blended->num_ents_allocated), FmtUint(g->ss_blended->num_ents_reserved));
             UI_BuildLabelF("Blended world tick:                 %F", FmtUint(g->ss_blended->tick));

src/pp/pp.h

@@ -33,6 +33,7 @@ Enum(PP_BindKind)
     PP_BindKind_DebugTeleport,
     PP_BindKind_DebugExplode,
     PP_BindKind_DebugToggleTopmost,
+    PP_BindKind_DebugUi,
     PP_BindKind_FullscreenMod,
     PP_BindKind_Fullscreen,
     PP_BindKind_ZoomIn,
@@ -83,6 +84,7 @@ Global Readonly PP_BindKind g_binds[Btn_Count] = {
     [Btn_F3]            = PP_BindKind_DebugDraw,
     [Btn_Tab]           = PP_BindKind_DebugLister,
     [Btn_F4]            = PP_BindKind_DebugToggleTopmost,
+    [Btn_F5]            = PP_BindKind_DebugUi,
     [Btn_GraveAccent]   = PP_BindKind_DebugConsole,
     [Btn_Alt]           = PP_BindKind_FullscreenMod,
     [Btn_Enter]         = PP_BindKind_Fullscreen,
@@ -245,6 +247,8 @@ Struct(PP_SharedUserState)
 
     //- Debug ui
 
+    b32 ui_debug;
+
     PP_EntKey debug_following;
     Vec2 debug_camera_pan_start;
     b32 debug_camera_panning;

src/pp/pp_widgets.c

@@ -124,9 +124,9 @@ UI_Box *PP_BuildDebugConsole(b32 minimized)
                         UI_Box *log_box = UI_BuildBox(Zstr);
                         UI_PushCP(log_box);
                         {
+                            UI_SetNext(Padding, UI_PADALL(UI_FNT(0.25, 0)));
                             UI_SetNext(BackgroundColor, 0);
                             UI_SetNext(Border, 0);
-                            UI_SetNext(Padding, 6);
                             UI_SetNext(Text, text);
                             UI_SetNext(Width, UI_FILL(1, 0));
                             UI_SetNext(Height, UI_FIT(1));

src/ui/ui_common.c

@@ -1,6 +1,5 @@
 ////////////////////////////////////////////////////////////
-//~ Label widget
+//~ Label helpers
-
 UI_Box *UI_BuildLabel(String text)
 {
     UI_SetNext(Width, UI_FIT(0));
@@ -27,19 +26,32 @@ UI_Box *UI_BuildLabelF_(char *fmt_cstr, ...)
 }
 
 ////////////////////////////////////////////////////////////
-//~ Spacing widgets
+//~ Spacing helpers
 
 UI_Box *UI_BuildSpacer(UI_Size size)
 {
-    UI_SetNext(Tint, 0);
+    UI_Box *box = 0;
-    if (UI_PeekTop(Parent)->layout_axis == Axis_X)
+
+    UI_Size old_width = UI_PeekTop(Width);
+    UI_Size old_height = UI_PeekTop(Height);
+    UI_Box *old_parent = UI_PeekTop(Parent);
+
+    UI_PushStack();
     {
-        UI_SetNext(Width, size);
+        UI_SetNext(Tint, 0);
+        UI_SetNext(Parent, old_parent);
+        if (old_parent->layout_axis == Axis_X)
+        {
+            UI_SetNext(Width, size);
+            UI_SetNext(Height, old_height);
+        }
+        else
+        {
+            UI_SetNext(Width, old_width);
+            UI_SetNext(Height, size);
+        }
+        box = UI_BuildBox(Zstr);
     }
-    else
+    UI_PopStack();
-    {
-        UI_SetNext(Height, size);
-    }
-    UI_Box *box = UI_BuildBox(Zstr);
     return box;
 }

src/ui/ui_common.h

@@ -1,11 +1,11 @@
 ////////////////////////////////////////////////////////////
-//~ Label widget
+//~ Label helpers
 
 UI_Box *UI_BuildLabel(String text);
 #define UI_BuildLabelF(fmt_cstr, ...) UI_BuildLabelF_(fmt_cstr, __VA_ARGS__, FmtEnd)
 UI_Box *UI_BuildLabelF_(char *fmt_cstr, ...);
 
 ////////////////////////////////////////////////////////////
-//~ Spacing widgets
+//~ Spacing helpers
 
 UI_Box *UI_BuildSpacer(UI_Size size);

src/ui/ui_core.c

@@ -65,6 +65,7 @@ UI_Box *UI_FrontBoxFromKey(UI_Key key)
 void UI_PushCP(UI_Box *parent)
 {
     UI_SharedState *g = &UI_shared_state;
+    UI_Stack *stack = g->top_stack;
     UI_Checkpoint *cp = g->first_free_checkpoint;
     if (cp)
     {
@@ -75,9 +76,9 @@ void UI_PushCP(UI_Box *parent)
     {
         cp = PushStruct(g->build_arena, UI_Checkpoint);
     }
-    cp->next = g->top_checkpoint;
+    cp->next = stack->top_checkpoint;
-    cp->v = g->top_checkpoint->v + 1;
+    cp->v = stack->top_checkpoint->v + 1;
-    g->top_checkpoint = cp;
+    stack->top_checkpoint = cp;
     if (parent != 0)
     {
         UI_Push(Parent, parent);
@@ -87,22 +88,23 @@ void UI_PushCP(UI_Box *parent)
 void UI_PopCP(void)
 {
     UI_SharedState *g = &UI_shared_state;
-    UI_Checkpoint *cp = g->top_checkpoint;
+    UI_Stack *stack = g->top_stack;
+    UI_Checkpoint *cp = stack->top_checkpoint;
     u64 v = cp->v;
     /* Pop styles */
     for (UI_StyleKind kind = UI_StyleKind_None; kind < UI_StyleKind_Count; ++kind)
     {
-        UI_StyleNode *n = g->style_tops[kind];
+        UI_StyleNode *n = stack->style_tops[kind];
         while (n && n->checkpoint >= v)
         {
             UI_StyleNode *next = n->next;
             n->next = g->first_free_style_node;
             g->first_free_style_node = n;
-            g->style_tops[kind] = next;
+            stack->style_tops[kind] = next;
             n = next;
         }
     }
-    g->top_checkpoint = cp->next;
+    stack->top_checkpoint = cp->next;
     cp->next = g->first_free_checkpoint;
     g->first_free_checkpoint = cp;
 }
@@ -110,101 +112,321 @@ void UI_PopCP(void)
 ////////////////////////////////////////////////////////////
 //~ Style stack helpers
 
-UI_StyleNode *UI_PushStyleNode(UI_Style desc)
+void UI_PushStack(void)
 {
     UI_SharedState *g = &UI_shared_state;
-    UI_StyleNode *n = g->style_tops[desc.kind];
+    UI_Stack *stack = PushStruct(g->build_arena, UI_Stack);
-    b32 cancel = 0;
+
-    if (!n->style.forced)
+    /* Init checkpoint */
     {
+        UI_Checkpoint *cp = g->first_free_checkpoint;
+        if (cp)
         {
-            if (n->style.pop_when_used)
+            g->first_free_checkpoint = cp->next;
+            ZeroStruct(cp);
+        }
+        else
+        {
+            cp = PushStruct(g->build_arena, UI_Checkpoint);
+        }
+        stack->top_checkpoint = cp;
+    }
+
+    /* Init styles */
+    {
+        for (UI_StyleKind kind = UI_StyleKind_None; kind < UI_StyleKind_Count; ++kind)
+        {
+            UI_StyleNode *n = g->first_free_style_node;
+            if (n)
             {
+                g->first_free_style_node = n->next;
                 ZeroStruct(n);
             }
             else
             {
-                n = g->first_free_style_node;
+                n = PushStruct(g->build_arena, UI_StyleNode);
-                if (n)
-                {
-                    g->first_free_style_node = n->next;
-                    ZeroStruct(n);
-                }
-                else
-                {
-                    n = PushStruct(g->build_arena, UI_StyleNode);
-                }
-                n->next = g->style_tops[desc.kind];
             }
-            n->style = desc;
+            n->style.kind = kind;
-            n->checkpoint = g->top_checkpoint->v;
+            stack->style_tops[kind] = n;
         }
+        stack->style_tops[UI_StyleKind_Parent]->style.Parent        = g->root_box;
+        stack->style_tops[UI_StyleKind_Width]->style.Width          = UI_FILL(1, 0);
+        stack->style_tops[UI_StyleKind_Height]->style.Height        = UI_FILL(1, 0);
+        stack->style_tops[UI_StyleKind_Font]->style.Font            = UI_GetDefaultFontResource();
+        stack->style_tops[UI_StyleKind_FontSize]->style.FontSize    = 16.0f;
+        stack->style_tops[UI_StyleKind_Tint]->style.Tint            = 0xFFFFFFFF;
+        stack->style_tops[UI_StyleKind_Tag]->style.Tag.name         = Lit("root");
+        stack->style_tops[UI_StyleKind_Tag]->style.Tag.hash         = HashFnv64(Fnv64Basis, stack->style_tops[UI_StyleKind_Tag]->style.Tag.name);
+    }
 
-        /* Initialize style data from desc */
+    stack->next = g->top_stack;
-        switch (desc.kind)
+    g->top_stack = stack;
+}
+
+void UI_PopStack(void)
+{
+    UI_SharedState *g = &UI_shared_state;
+    UI_Stack *stack = g->top_stack;
+
+    /* Free checkpoints */
+    {
+        UI_Checkpoint *cp = stack->top_checkpoint;
+        while (cp)
+        {
+            UI_Checkpoint *next = cp->next;
+            cp->next = g->first_free_checkpoint;
+            g->first_free_checkpoint = cp;
+            cp = next;
+        }
+    }
+
+    /* Free style nodes */
+    for (UI_StyleKind kind = UI_StyleKind_None; kind < UI_StyleKind_Count; ++kind)
+    {
+        UI_StyleNode *n = stack->style_tops[kind];
+        while (n)
+        {
+            UI_StyleNode *next = n->next;
+            n->next = g->first_free_style_node;
+            g->first_free_style_node = n;
+            n = next;
+        }
+    }
+
+    g->top_stack = stack->next;
+    stack->next = g->first_free_stack;
+    g->first_free_stack = stack;
+}
+
+void UI_PushStyle(UI_Style desc)
+{
+    UI_SharedState *g = &UI_shared_state;
+    UI_Stack *stack = g->top_stack;
+
+    if (desc.kind >= UI_StyleKind_BeginVirtualStyles_)
+    {
+        switch(desc.kind)
         {
             default: break;
 
-            case UI_StyleKind_Text:
+            case UI_StyleKind_Padding:
             {
-                n->style.Text = PushString(g->build_arena, desc.Text);
+                UI_Pad pad = desc.Padding;
-            } break;
+                UI_PushCopy(TopPadding,    desc, pad.top);
-
+                UI_PushCopy(BottomPadding, desc, pad.bottom);
-            case UI_StyleKind_Tag:
+                UI_PushCopy(LeftPadding,   desc, pad.left);
-            {
+                UI_PushCopy(RightPadding,  desc, pad.right);
-                n->style.Tag.name = PushString(g->build_arena, desc.Tag.name);
-                if (n->style.Tag.hash == 0)
-                {
-                    n->style.Tag.hash = HashFnv64(g->style_tops[desc.kind]->style.Tag.hash, n->style.Tag.name);
-                }
             } break;
         }
     }
-    g->style_tops[desc.kind] = n;
+    else
-    return n;
+    {
+        UI_StyleNode *n = stack->style_tops[desc.kind];
+        if (!n->style.forced)
+        {
+            {
+                if (n->style.pop_when_used)
+                {
+                    UI_StyleNode *next = n->next;
+                    ZeroStruct(n);
+                    n->next = next;
+                }
+                else
+                {
+                    n = g->first_free_style_node;
+                    if (n)
+                    {
+                        g->first_free_style_node = n->next;
+                        ZeroStruct(n);
+                    }
+                    else
+                    {
+                        n = PushStruct(g->build_arena, UI_StyleNode);
+                    }
+                    n->next = stack->style_tops[desc.kind];
+                    stack->style_tops[desc.kind] = n;
+                }
+                n->style = desc;
+                n->checkpoint = stack->top_checkpoint->v;
+            }
+
+            /* Initialize style data from desc */
+            switch (desc.kind)
+            {
+                default: break;
+
+                case UI_StyleKind_Text:
+                {
+                    n->style.Text = PushString(g->build_arena, desc.Text);
+                } break;
+
+                case UI_StyleKind_Tag:
+                {
+                    n->style.Tag.name = PushString(g->build_arena, desc.Tag.name);
+                    if (n->style.Tag.hash == 0)
+                    {
+                        n->style.Tag.hash = HashFnv64(stack->style_tops[desc.kind]->style.Tag.hash, n->style.Tag.name);
+                    }
+                } break;
+            }
+        }
+    }
 }
 
-UI_Style UI_PopStyleNode(UI_StyleKind kind)
+UI_Style UI_PopStyle(UI_StyleKind kind)
 {
     UI_SharedState *g = &UI_shared_state;
-    UI_StyleNode *n = g->style_tops[kind];
+    UI_Stack *stack = g->top_stack;
+    UI_StyleNode *n = stack->style_tops[kind];
     UI_Style style = n->style;
-    g->style_tops[kind] = n->next;
+    stack->style_tops[kind] = n->next;
     n->next = g->first_free_style_node;
     g->first_free_style_node = n;
     return style;
 }
 
-UI_StyleNode *UI_PeekStyleNode(UI_StyleKind kind)
+UI_Style UI_FetchStyle(UI_StyleKind kind, b32 use)
 {
     UI_SharedState *g = &UI_shared_state;
-    UI_StyleNode *n = g->style_tops[kind];
+    UI_Stack *stack = g->top_stack;
-    return n;
+    UI_Style result = ZI;
-}
+    result.kind = kind;
-
+    if (kind >= UI_StyleKind_BeginVirtualStyles_)
-UI_Style UI_StyleFromTopNode(UI_StyleKind kind, b32 use)
-{
-    UI_SharedState *g = &UI_shared_state;
-    UI_StyleNode *n = g->style_tops[kind];
-    UI_Style style = n->style;
-    if (use && n->style.pop_when_used)
     {
-        g->style_tops[kind] = n->next;
+        switch(kind)
-        n->next = g->first_free_style_node;
+        {
-        g->first_free_style_node = n;
+            default: break;
+
+            case UI_StyleKind_Padding:
+            {
+                result.Padding.top    = UI_FetchTop(TopPadding, use);
+                result.Padding.bottom = UI_FetchTop(BottomPadding, use);
+                result.Padding.left   = UI_FetchTop(LeftPadding, use);
+                result.Padding.right  = UI_FetchTop(RightPadding, use);
+            } break;
+        }
     }
-    return style;
+    else
+    {
+        UI_StyleNode *n = stack->style_tops[kind];
+        result = n->style;
+        if (use && n->style.pop_when_used)
+        {
+            stack->style_tops[kind] = n->next;
+            n->next = g->first_free_style_node;
+            g->first_free_style_node = n;
+        }
+
+    }
+    return result;
 }
 
 ////////////////////////////////////////////////////////////
-//~ Box helpers
+//~ Padding helpers
+
+UI_Box *UI_BuildPadAlongAxis(UI_Box *parent, UI_Size start, UI_Size end, Axis final_layout_axis)
+{
+    UI_Box *pad = parent;
+    b32 has_start_padding  = !(start.kind == UI_SizeKind_Pixel && start.v == 0);
+    b32 has_end_padding    = !(end.kind == UI_SizeKind_Pixel && end.v == 0);
+    UI_Size old_width = UI_PeekTop(Width);
+    UI_Size old_height = UI_PeekTop(Height);
+    {
+        UI_PushStack();
+        {
+            UI_PushCP(parent);
+            {
+                UI_ForcePush(Padding, UI_PIX(0, 0));
+                UI_Push(Tint, 0);
+                /* Start */
+                if (has_start_padding)
+                {
+                    if (parent->layout_axis == Axis_X)
+                    {
+                        UI_SetNext(Width, start);
+                        UI_SetNext(Height, old_height);
+                    }
+                    else
+                    {
+                        UI_SetNext(Width, old_width);
+                        UI_SetNext(Height, start);
+                    }
+                    UI_BuildBox(Zstr);
+                }
+                /* Pad */
+                {
+                    UI_SetNext(Width, old_width);
+                    UI_SetNext(Height, old_height);
+                    UI_SetNext(LayoutAxis, final_layout_axis);
+                    pad = UI_BuildBox(Zstr);
+                }
+                /* End */
+                if (has_end_padding)
+                {
+                    if (parent->layout_axis == Axis_X)
+                    {
+                        UI_SetNext(Width, end);
+                        UI_SetNext(Height, old_height);
+                    }
+                    else
+                    {
+                        UI_SetNext(Width, old_width);
+                        UI_SetNext(Height, end);
+                    }
+                    UI_BuildBox(Zstr);
+                }
+            }
+            UI_PopCP();
+        }
+        UI_PopStack();
+    }
+    return pad;
+}
+
+UI_Box *UI_BuildPad(UI_Box *parent, UI_Pad padding)
+{
+    UI_Box *pad = parent;
+    b32 has_top_padding     = !(padding.top.kind == UI_SizeKind_Pixel && padding.top.v == 0);
+    b32 has_bottom_padding  = !(padding.bottom.kind == UI_SizeKind_Pixel && padding.bottom.v == 0);
+    b32 has_left_padding    = !(padding.left.kind == UI_SizeKind_Pixel && padding.left.v == 0);
+    b32 has_right_padding   = !(padding.right.kind == UI_SizeKind_Pixel && padding.right.v == 0);
+    if (has_top_padding || has_bottom_padding || has_left_padding || has_right_padding)
+    {
+        if (parent->layout_axis == Axis_X)
+        {
+            b32 needs_second_pass = has_top_padding || has_bottom_padding;
+            pad = UI_BuildPadAlongAxis(pad, padding.left, padding.right, needs_second_pass ? Axis_Y : Axis_X);
+            if (needs_second_pass)
+            {
+                pad = UI_BuildPadAlongAxis(pad, padding.top, padding.bottom, Axis_X);
+            }
+        }
+        else
+        {
+            b32 needs_second_pass = has_left_padding || has_right_padding;
+            pad = UI_BuildPadAlongAxis(pad, padding.top, padding.bottom, needs_second_pass ? Axis_X : Axis_Y);
+            if (needs_second_pass)
+            {
+                pad = UI_BuildPadAlongAxis(pad, padding.left, padding.right, Axis_Y);
+            }
+        }
+    }
+    return pad;
+}
+
+////////////////////////////////////////////////////////////
+//~ Box
 
 UI_Box *UI_BuildBox(String seed)
 {
     UI_SharedState *g = &UI_shared_state;
+    UI_Box *parent = UI_UseTop(Parent);
+
+    /* Create padding */
+    UI_Pad padding = UI_UseTop(Padding);
+    parent = UI_BuildPad(parent, padding);
 
     /* Calculate key */
-    UI_Box *parent = UI_UseTop(Parent);
     UI_Tag tag     = UI_UseTop(Tag);
     UI_Key key = ZI;
     if (seed.len > 0)
@@ -259,7 +481,6 @@ UI_Box *UI_BuildBox(String seed)
     box->border                 = UI_UseTop(Border);
     box->font_resource          = UI_UseTop(Font);
     box->font_size              = UI_UseTop(FontSize);
-    box->padding                = UI_UseTop(Padding);
     box->rounding               = UI_UseTop(Rounding);
     box->text                   = UI_UseTop(Text);
     box->floating_pos           = UI_UseTop(FloatingPos);
@@ -304,7 +525,7 @@ UI_Event UI_EventFromKey(UI_Key key)
 ////////////////////////////////////////////////////////////
 //~ Begin build
 
-void UI_BeginBuild(ControllerEventsArray controller_events)
+void UI_BeginBuild(ControllerEventsArray controller_events, UI_BuildFlag build_flags)
 {
     UI_SharedState *g = &UI_shared_state;
 
@@ -409,6 +630,7 @@ void UI_BeginBuild(ControllerEventsArray controller_events)
         g->back_boxes_count = g->boxes_count;
         g->back_boxes_pre = g->boxes_pre;
         g->back_boxes_post = g->boxes_post;
+        g->back_build_flags = g->build_flags;
     }
 
     //////////////////////////////
@@ -423,6 +645,9 @@ void UI_BeginBuild(ControllerEventsArray controller_events)
         g->boxes_count = 0;
         g->first_free_style_node = 0;
         g->first_free_checkpoint = 0;
+        g->first_free_stack = 0;
+
+        g->build_flags = build_flags;
 
         /* Init bins */
         g->box_bins = PushStructs(g->build_arena, UI_BoxBin, UI_NumBoxLookupBins);
@@ -437,38 +662,14 @@ void UI_BeginBuild(ControllerEventsArray controller_events)
         if (!g->back_build_arena)
         {
             /* Back buffer not initialized, swap again */
-            UI_BeginBuild(controller_events);
+            UI_BeginBuild(controller_events, build_flags);
         }
     }
 
-
     //////////////////////////////
     //- Init style stack
 
-    {
+    UI_PushStack();
-        /* Init checkpoints */
-        g->top_checkpoint = PushStruct(g->build_arena, UI_Checkpoint);
-
-        /* Init styles */
-        {
-            UI_StyleNode *nodes = PushStructs(g->build_arena, UI_StyleNode, UI_StyleKind_Count);
-            for (UI_StyleKind kind = UI_StyleKind_None; kind < UI_StyleKind_Count; ++kind)
-            {
-                UI_StyleNode *n = &nodes[kind];
-                UI_Style *style = &n->style;
-                style->kind = kind;
-                g->style_tops[kind] = n;
-            }
-            g->style_tops[UI_StyleKind_Parent]->style.Parent        = g->root_box;
-            g->style_tops[UI_StyleKind_Width]->style.Width          = UI_FILL(1, 0);
-            g->style_tops[UI_StyleKind_Height]->style.Height        = UI_FILL(1, 0);
-            g->style_tops[UI_StyleKind_Font]->style.Font            = UI_GetDefaultFontResource();
-            g->style_tops[UI_StyleKind_FontSize]->style.FontSize    = 16.0f;
-            g->style_tops[UI_StyleKind_Tint]->style.Tint            = 0xFFFFFFFF;
-            g->style_tops[UI_StyleKind_Tag]->style.Tag.name         = Lit("root");
-            g->style_tops[UI_StyleKind_Tag]->style.Tag.hash         = HashFnv64(Fnv64Basis, g->style_tops[UI_StyleKind_Tag]->style.Tag.name);
-        }
-    }
 }
 
 ////////////////////////////////////////////////////////////
@@ -594,7 +795,7 @@ i64 UI_EndBuild(GPU_Resource *render_target, Xform ui_to_screen_xf)
                         text_size = box->font->ascent + box->font->descent;
                     }
                 }
-                box->solved_dims[axis] = text_size + box->padding * 2;
+                box->solved_dims[axis] = text_size;
             }
         }
     }
@@ -840,7 +1041,7 @@ i64 UI_EndBuild(GPU_Resource *render_target, Xform ui_to_screen_xf)
         is_visible = is_visible && ((box->tint & 0xFF000000) != 0);
         is_visible = is_visible && (box->p1.x > box->p0.x);
         is_visible = is_visible && (box->p1.y > box->p0.y);
-        if (is_visible || UI_DEBUG)
+        if (is_visible || AnyBit(g->build_flags, UI_BuildFlag_Debug))
         {
             /* Box rect */
             {
@@ -905,13 +1106,12 @@ i64 UI_EndBuild(GPU_Resource *render_target, Xform ui_to_screen_xf)
 
                 f32 ascent = box->font->ascent;
                 f32 descent = box->font->descent;
-                f32 padding = box->padding;
 
                 Vec2 baseline = box->p0;
-                baseline = AddVec2(baseline, VEC2(padding, padding + ascent));
+                baseline.y += ascent;
 
                 F_Run run = box->glyph_run;
-                f32 max_baseline = box->p1.x - (padding * 2);
+                f32 max_baseline = box->p1.x;
                 b32 should_truncate = run.count > 0 && (run.rects[run.count - 1].pos + run.rects[run.count - 1].advance) > max_baseline;
 
                 /* Truncate run */
@@ -1021,7 +1221,7 @@ i64 UI_EndBuild(GPU_Resource *render_target, Xform ui_to_screen_xf)
             }
 
             /* Render rect wireframes */
-            if (UI_DEBUG)
+            if (AnyBit(g->build_flags, UI_BuildFlag_Debug))
             {
                 UI_RectSig sig        = ZI;
                 sig.viewport_size     = RoundVec2ToVec2I32(render_viewport.size);

src/ui/ui_core.h

@@ -9,14 +9,23 @@ Struct(UI_Key)
     u64 hash;
 };
 
+////////////////////////////////////////////////////////////
+//~ Build flags
+
+Enum(UI_BuildFlag)
+{
+    UI_BuildFlag_None  = 0,
+    UI_BuildFlag_Debug = (1 << 0),
+};
+
 ////////////////////////////////////////////////////////////
 //~ Size types
 
 Enum(UI_SizeKind)
 {
-    UI_SizeKind_Fit,    /* Size to contents */
-    UI_SizeKind_Fill,   /* Size as percent of parent size */
     UI_SizeKind_Pixel,  /* Exact size */
+    UI_SizeKind_Fill,   /* Size as percent of parent size */
+    UI_SizeKind_Fit,    /* Size to contents */
 };
 
 Struct(UI_Size)
@@ -42,7 +51,27 @@ Struct(UI_Round)
 };
 
 ////////////////////////////////////////////////////////////
-//~ Box flag types
+//~ Padding types
+
+Struct(UI_Pad)
+{
+    UI_Size top;
+    UI_Size bottom;
+    UI_Size left;
+    UI_Size right;
+};
+
+////////////////////////////////////////////////////////////
+//~ Checkpoint types
+
+Struct(UI_Checkpoint)
+{
+    UI_Checkpoint *next;
+    u64 v;
+};
+
+////////////////////////////////////////////////////////////
+//~ Box flags
 
 Enum(UI_BoxFlag)
 {
@@ -68,12 +97,20 @@ Enum(UI_BoxFlag)
     x(BorderColor,          u32)                \
     x(Tint,                 u32)                \
     x(Border,               f32)                \
+    x(FloatingPos,          Vec2)               \
+    x(Rounding,             UI_Round)           \
     x(Font,                 ResourceKey)        \
     x(FontSize,             u32)                \
     x(Text,                 String)             \
-    x(Padding,              f32)                \
+    x(LeftPadding,          UI_Size)            \
-    x(Rounding,             UI_Round)           \
+    x(RightPadding,         UI_Size)            \
-    x(FloatingPos,          Vec2)               \
+    x(TopPadding,           UI_Size)            \
+    x(BottomPadding,        UI_Size)            \
+    /*  ----------------------------------- */  \
+    /*  --------- Virtual styles  --------- */  \
+    /*  ----------------------------------- */  \
+    x(BeginVirtualStyles_,  i8)                 \
+    x(Padding,              UI_Pad)             \
 /* ------------------------------------------- */
 
 Struct(UI_Tag)
@@ -112,13 +149,12 @@ Struct(UI_StyleNode)
     UI_Style style;
 };
 
-////////////////////////////////////////////////////////////
+Struct(UI_Stack)
-//~ Checkpoint types
-
-Struct(UI_Checkpoint)
 {
-    UI_Checkpoint *next;
+    UI_Stack *next;
-    u64 v;
+
+    UI_Checkpoint *top_checkpoint;
+    UI_StyleNode *style_tops[UI_StyleKind_Count];
 };
 
 ////////////////////////////////////////////////////////////
@@ -174,10 +210,9 @@ Struct(UI_Box)
     f32 border;
     Vec2 floating_pos;
     String text;
-    Axis layout_axis;
     ResourceKey font_resource;
     f32 font_size;
-    f32 padding;
+    Axis layout_axis;
 
     //- Pre-layout data
     u64 pre_index;
@@ -219,6 +254,9 @@ Struct(UI_SharedState)
     Arena *build_arena;
     Arena *back_build_arena;
 
+    UI_BuildFlag build_flags;
+    UI_BuildFlag back_build_flags;
+
     UI_BoxBin *box_bins;
     UI_BoxBin *back_box_bins;
 
@@ -228,8 +266,8 @@ Struct(UI_SharedState)
     u64 boxes_count;
     u64 back_boxes_count;
 
-    UI_Checkpoint *top_checkpoint;
+    UI_Stack *top_stack;
-    UI_StyleNode *style_tops[UI_StyleKind_Count];
+    UI_Stack *first_free_stack;
     UI_Checkpoint *first_free_checkpoint;
     UI_StyleNode *first_free_style_node;
 
@@ -269,20 +307,30 @@ void UI_PushCP(UI_Box *parent);
 void UI_PopCP(void);
 
 ////////////////////////////////////////////////////////////
-//~ Style helpers
+//~ Style stack helpers
 
-UI_StyleNode    *UI_PushStyleNode(UI_Style desc);
+void UI_PushStack(void);
-UI_Style         UI_PopStyleNode(UI_StyleKind kind);
+void UI_PopStack(void);
-UI_StyleNode    *UI_PeekTopStyleNode(UI_StyleKind kind);
-UI_Style         UI_StyleFromTopNode(UI_StyleKind kind, b32 use);
 
-#define UI_SetNext(name, ...)       UI_PushStyleNode((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__, .pop_when_used = 1 })
+void     UI_PushStyle(UI_Style desc);
-#define UI_Push(name, ...)          UI_PushStyleNode((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__ })
+UI_Style UI_PopStyle(UI_StyleKind kind);
-#define UI_ForceNext(name, ...)     UI_PushStyleNode((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__, .pop_when_used = 1, .forced = 1 })
+UI_Style UI_FetchStyle(UI_StyleKind kind, b32 use);
-#define UI_ForcePush(name, ...)     UI_PushStyleNode((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__, .forced = 1 })
+
-#define UI_Pop(name)                UI_PopStyleNode(UI_StyleKind_##name).name
+#define UI_SetNext(name, ...)       UI_PushStyle((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__, .pop_when_used = 1 })
-#define UI_UseTop(name)             UI_StyleFromTopNode(UI_StyleKind_##name, 1).name
+#define UI_Push(name, ...)          UI_PushStyle((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__ })
-#define UI_PeekTop(name)            UI_StyleFromTopNode(UI_StyleKind_##name, 0).name
+#define UI_ForceNext(name, ...)     UI_PushStyle((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__, .pop_when_used = 1, .forced = 1 })
+#define UI_ForcePush(name, ...)     UI_PushStyle((UI_Style) { .kind = UI_StyleKind_##name, .name = __VA_ARGS__, .forced = 1 })
+#define UI_Pop(name)                UI_PopStyle(UI_StyleKind_##name).name
+#define UI_FetchTop(name, use)      UI_FetchStyle(UI_StyleKind_##name, use).name
+#define UI_PeekTop(name)            UI_FetchTop(name, 0)
+#define UI_UseTop(name)             UI_FetchTop(name, 1)
+
+#define UI_PushCopy(name, src, ...) do {  \
+    UI_Style _new = src;                  \
+    _new.kind = UI_StyleKind_##name;      \
+    _new.name = __VA_ARGS__;              \
+    UI_PushStyle(_new);                   \
+} while (0)
 
 ////////////////////////////////////////////////////////////
 //~ Size helpers
@@ -302,6 +350,15 @@ UI_Style         UI_StyleFromTopNode(UI_StyleKind kind, b32 use);
 #define UI_RPIX(_v) UI_ROUND(UI_RoundKind_Pixel, (_v))
 #define UI_RFILL(_v) UI_ROUND(UI_RoundKind_Fill, (_v))
 
+////////////////////////////////////////////////////////////
+//~ Padding helpers
+
+#define UI_PAD(...)   ((UI_Pad) { __VA_ARGS__ })
+#define UI_PADALL(size)    ((UI_Pad) { .top = size, .bottom = size, .left = size, .right = size })
+
+UI_Box *UI_BuildPadAlongAxis(UI_Box *parent, UI_Size start, UI_Size end, Axis final_layout_axis);
+UI_Box *UI_BuildPad(UI_Box *parent, UI_Pad padding);
+
 ////////////////////////////////////////////////////////////
 //~ Box
 
@@ -317,7 +374,7 @@ UI_Event UI_EventFromKey(UI_Key key);
 ////////////////////////////////////////////////////////////
 //~ Begin build
 
-void UI_BeginBuild(ControllerEventsArray controller_events);
+void UI_BeginBuild(ControllerEventsArray controller_events, UI_BuildFlag flags);
 
 ////////////////////////////////////////////////////////////
 //~ End build