Added GDI full featured window code

demo/gdi_native_nuklear/build.bat

@@ -0,0 +1,6 @@
+@echo off
+
+rem This will use VS2015 for compiler
+call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x86
+
+cl /nologo /W3 /O2 /fp:fast /Gm- /D_CRT_SECURE_NO_DEPRECATE /Fedemo.exe main.cpp user32.lib gdi32.lib Msimg32.lib /link /incremental:no 

demo/gdi_native_nuklear/main.cpp

@@ -0,0 +1,37 @@
+#include <Windows.h>
+#include <iostream>
+
+#pragma comment(linker,"\"/manifestdependency:type='win32' \
+name='Microsoft.Windows.Common-Controls' version='6.0.0.0' \
+processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
+
+#define NK_INCLUDE_FIXED_TYPES
+#define NK_INCLUDE_STANDARD_IO
+#define NK_INCLUDE_STANDARD_VARARGS
+#define NK_INCLUDE_DEFAULT_ALLOCATOR
+#define NK_IMPLEMENTATION
+#define NK_GDI_IMPLEMENTATION
+#include "../../nuklear.h"
+#include "nuklear_gdi.h"
+
+#define NKGDI_IMPLEMENT_WINDOW
+#include "window.h"
+
+INT WINAPI wWinMain(HINSTANCE _In_ hInstance, HINSTANCE _In_opt_ hPrevInstance, PWSTR _In_ cmdArgs, INT _In_ cmdShow)
+{
+    NkGdi::Window w1(500, 500, "F1", 10, 10);
+    w1.AllowSizing = false;
+    w1.AllowMaximize = false;
+    w1.AllowMove = false;
+    w1.HasTitlebar = false;
+
+    NkGdi::Window w2(500, 500, "F2", 520, 10);
+    w2.AllowSizing = true;
+    w2.AllowMaximize = true;
+    w2.AllowMove = true;
+    w2.HasTitlebar = true;
+    
+    while (w1.Update() && w2.Update()) Sleep(20);
+
+    return 0;
+}

demo/gdi_native_nuklear/nuklear_gdi.h

@@ -0,0 +1,932 @@
+/*
+ * Nuklear - 1.32.0 - public domain
+ * no warrenty implied; use at your own risk.
+ * authored from 2015-2016 by Micha Mettke
+ */
+ /*
+  * ==============================================================
+  *
+  *                              API
+  *
+  * ===============================================================
+  */
+#ifndef NK_GDI_H_
+#define NK_GDI_H_
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+typedef struct GdiFont GdiFont;
+struct _nk_gdi_ctx;
+typedef struct _nk_gdi_ctx* nk_gdi_ctx;
+
+NK_API struct nk_context* nk_gdi_init(nk_gdi_ctx* gdi, GdiFont* font, HDC window_dc, unsigned int width, unsigned int height);
+NK_API int nk_gdi_handle_event(nk_gdi_ctx gdi, HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam);
+NK_API void nk_gdi_render(nk_gdi_ctx gdi, struct nk_color clear);
+NK_API void nk_gdi_shutdown(nk_gdi_ctx gdi);
+
+/* font */
+NK_API GdiFont* nk_gdifont_create(const char* name, int size);
+NK_API void nk_gdifont_del(GdiFont* font);
+NK_API void nk_gdi_set_font(nk_gdi_ctx gdi, GdiFont* font);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+/*
+ * ==============================================================
+ *
+ *                          IMPLEMENTATION
+ *
+ * ===============================================================
+ */
+#ifdef NK_GDI_IMPLEMENTATION
+
+#include <stdlib.h>
+#include <malloc.h>
+
+struct GdiFont {
+    struct nk_user_font nk;
+    int height;
+    HFONT handle;
+    HDC dc;
+};
+
+struct _nk_gdi_ctx {
+    HBITMAP bitmap;
+    HDC window_dc;
+    HDC memory_dc;
+    unsigned int width;
+    unsigned int height;
+    struct nk_context ctx;
+};
+
+static void
+nk_create_image(struct nk_image* image, const char* frame_buffer, const int width, const int height)
+{
+    if (image && frame_buffer && (width > 0) && (height > 0))
+    {
+        const unsigned char* src = (const unsigned char*)frame_buffer;
+        INT row = ((width * 3 + 3) & ~3);
+        LPBYTE lpBuf, pb = NULL;
+        BITMAPINFO bi = { 0 };
+        HBITMAP hbm;
+        int v, i;
+
+        image->w = width;
+        image->h = height;
+        image->region[0] = 0;
+        image->region[1] = 0;
+        image->region[2] = width;
+        image->region[3] = height;
+
+        bi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+        bi.bmiHeader.biWidth = width;
+        bi.bmiHeader.biHeight = height;
+        bi.bmiHeader.biPlanes = 1;
+        bi.bmiHeader.biBitCount = 24;
+        bi.bmiHeader.biCompression = BI_RGB;
+        bi.bmiHeader.biSizeImage = row * height;
+
+        hbm = CreateDIBSection(NULL, &bi, DIB_RGB_COLORS, (void**)&lpBuf, NULL, 0);
+
+        pb = lpBuf + row * height;
+        for (v = 0; v < height; v++)
+        {
+            pb -= row;
+            for (i = 0; i < row; i += 3)
+            {
+                pb[i + 0] = src[0];
+                pb[i + 1] = src[1];
+                pb[i + 2] = src[2];
+                src += 3;
+            }
+        }
+        SetDIBits(NULL, hbm, 0, height, lpBuf, &bi, DIB_RGB_COLORS);
+        image->handle.ptr = hbm;
+    }
+}
+
+static void
+nk_delete_image(struct nk_image* image)
+{
+    if (image && image->handle.id != 0)
+    {
+        HBITMAP hbm = (HBITMAP)image->handle.ptr;
+        DeleteObject(hbm);
+        memset(image, 0, sizeof(struct nk_image));
+    }
+}
+
+static void
+nk_gdi_draw_image(nk_gdi_ctx gdi, short x, short y, unsigned short w, unsigned short h,
+    struct nk_image img, struct nk_color col)
+{
+    HBITMAP hbm = (HBITMAP)img.handle.ptr;
+    HDC     hDCBits;
+    BITMAP  bitmap;
+
+    if (!gdi->memory_dc || !hbm)
+        return;
+
+    hDCBits = CreateCompatibleDC(gdi->memory_dc);
+    GetObject(hbm, sizeof(BITMAP), (LPSTR)&bitmap);
+    SelectObject(hDCBits, hbm);
+    StretchBlt(gdi->memory_dc, x, y, w, h, hDCBits, 0, 0, bitmap.bmWidth, bitmap.bmHeight, SRCCOPY);
+    DeleteDC(hDCBits);
+}
+
+static COLORREF
+convert_color(struct nk_color c)
+{
+    return c.r | (c.g << 8) | (c.b << 16);
+}
+
+static void
+nk_gdi_scissor(HDC dc, float x, float y, float w, float h)
+{
+    SelectClipRgn(dc, NULL);
+    IntersectClipRect(dc, (int)x, (int)y, (int)(x + w + 1), (int)(y + h + 1));
+}
+
+static void
+nk_gdi_stroke_line(HDC dc, short x0, short y0, short x1,
+    short y1, unsigned int line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+
+    HPEN pen = NULL;
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    MoveToEx(dc, x0, y0, NULL);
+    LineTo(dc, x1, y1);
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_stroke_rect(HDC dc, short x, short y, unsigned short w,
+    unsigned short h, unsigned short r, unsigned short line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    HGDIOBJ br;
+    HPEN pen = NULL;
+
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    br = SelectObject(dc, GetStockObject(NULL_BRUSH));
+    if (r == 0) {
+        Rectangle(dc, x, y, x + w, y + h);
+    }
+    else {
+        RoundRect(dc, x, y, x + w, y + h, r, r);
+    }
+    SelectObject(dc, br);
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_fill_rect(HDC dc, short x, short y, unsigned short w,
+    unsigned short h, unsigned short r, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+
+    if (r == 0) {
+        RECT rect;
+        SetRect(&rect, x, y, x + w, y + h);
+        SetBkColor(dc, color);
+        ExtTextOutW(dc, 0, 0, ETO_OPAQUE, &rect, NULL, 0, NULL);
+    }
+    else {
+        SetDCPenColor(dc, color);
+        SetDCBrushColor(dc, color);
+        RoundRect(dc, x, y, x + w, y + h, r, r);
+    }
+}
+static void
+nk_gdi_set_vertexColor(PTRIVERTEX tri, struct nk_color col)
+{
+    tri->Red = col.r << 8;
+    tri->Green = col.g << 8;
+    tri->Blue = col.b << 8;
+    tri->Alpha = 0xff << 8;
+}
+
+static void
+nk_gdi_rect_multi_color(nk_gdi_ctx gdi, HDC dc, short x, short y, unsigned short w,
+    unsigned short h, struct nk_color left, struct nk_color top,
+    struct nk_color right, struct nk_color bottom)
+{
+    BLENDFUNCTION alphaFunction;
+    // GRADIENT_RECT gRect;
+    GRADIENT_TRIANGLE gTri[2];
+    TRIVERTEX vt[4];
+    alphaFunction.BlendOp = AC_SRC_OVER;
+    alphaFunction.BlendFlags = 0;
+    alphaFunction.SourceConstantAlpha = 0;
+    alphaFunction.AlphaFormat = AC_SRC_ALPHA;
+
+    /* TODO: This Case Needs Repair.*/
+    /* Top Left Corner */
+    vt[0].x = x;
+    vt[0].y = y;
+    nk_gdi_set_vertexColor(&vt[0], left);
+    /* Top Right Corner */
+    vt[1].x = x + w;
+    vt[1].y = y;
+    nk_gdi_set_vertexColor(&vt[1], top);
+    /* Bottom Left Corner */
+    vt[2].x = x;
+    vt[2].y = y + h;
+    nk_gdi_set_vertexColor(&vt[2], right);
+
+    /* Bottom Right Corner */
+    vt[3].x = x + w;
+    vt[3].y = y + h;
+    nk_gdi_set_vertexColor(&vt[3], bottom);
+
+    gTri[0].Vertex1 = 0;
+    gTri[0].Vertex2 = 1;
+    gTri[0].Vertex3 = 2;
+    gTri[1].Vertex1 = 2;
+    gTri[1].Vertex2 = 1;
+    gTri[1].Vertex3 = 3;
+    GdiGradientFill(dc, vt, 4, gTri, 2, GRADIENT_FILL_TRIANGLE);
+    AlphaBlend(gdi->window_dc, x, y, x + w, y + h, gdi->memory_dc, x, y, x + w, y + h, alphaFunction);
+
+}
+
+static BOOL
+SetPoint(POINT* p, LONG x, LONG y)
+{
+    if (!p)
+        return FALSE;
+    p->x = x;
+    p->y = y;
+    return TRUE;
+}
+
+static void
+nk_gdi_fill_triangle(HDC dc, short x0, short y0, short x1,
+    short y1, short x2, short y2, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    POINT points[3];
+
+    SetPoint(&points[0], x0, y0);
+    SetPoint(&points[1], x1, y1);
+    SetPoint(&points[2], x2, y2);
+
+    SetDCPenColor(dc, color);
+    SetDCBrushColor(dc, color);
+    Polygon(dc, points, 3);
+}
+
+static void
+nk_gdi_stroke_triangle(HDC dc, short x0, short y0, short x1,
+    short y1, short x2, short y2, unsigned short line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    POINT points[4];
+    HPEN pen = NULL;
+
+    SetPoint(&points[0], x0, y0);
+    SetPoint(&points[1], x1, y1);
+    SetPoint(&points[2], x2, y2);
+    SetPoint(&points[3], x0, y0);
+
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    Polyline(dc, points, 4);
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_fill_polygon(HDC dc, const struct nk_vec2i* pnts, int count, struct nk_color col)
+{
+    int i = 0;
+#define MAX_POINTS 64
+    POINT points[MAX_POINTS];
+    COLORREF color = convert_color(col);
+    SetDCBrushColor(dc, color);
+    SetDCPenColor(dc, color);
+    for (i = 0; i < count && i < MAX_POINTS; ++i) {
+        points[i].x = pnts[i].x;
+        points[i].y = pnts[i].y;
+    }
+    Polygon(dc, points, i);
+#undef MAX_POINTS
+}
+
+static void
+nk_gdi_stroke_polygon(HDC dc, const struct nk_vec2i* pnts, int count,
+    unsigned short line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    HPEN pen = NULL;
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    if (count > 0) {
+        int i;
+        MoveToEx(dc, pnts[0].x, pnts[0].y, NULL);
+        for (i = 1; i < count; ++i)
+            LineTo(dc, pnts[i].x, pnts[i].y);
+        LineTo(dc, pnts[0].x, pnts[0].y);
+    }
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_stroke_polyline(HDC dc, const struct nk_vec2i* pnts,
+    int count, unsigned short line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    HPEN pen = NULL;
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    if (count > 0) {
+        int i;
+        MoveToEx(dc, pnts[0].x, pnts[0].y, NULL);
+        for (i = 1; i < count; ++i)
+            LineTo(dc, pnts[i].x, pnts[i].y);
+    }
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_fill_circle(HDC dc, short x, short y, unsigned short w,
+    unsigned short h, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    SetDCBrushColor(dc, color);
+    SetDCPenColor(dc, color);
+    Ellipse(dc, x, y, x + w, y + h);
+}
+
+static void
+nk_gdi_stroke_circle(HDC dc, short x, short y, unsigned short w,
+    unsigned short h, unsigned short line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    HPEN pen = NULL;
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    SetDCBrushColor(dc, OPAQUE);
+    Ellipse(dc, x, y, x + w, y + h);
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_stroke_curve(HDC dc, struct nk_vec2i p1,
+    struct nk_vec2i p2, struct nk_vec2i p3, struct nk_vec2i p4,
+    unsigned short line_thickness, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    POINT p[4];
+    HPEN pen = NULL;
+
+    SetPoint(&p[0], p1.x, p1.y);
+    SetPoint(&p[1], p2.x, p2.y);
+    SetPoint(&p[2], p3.x, p3.y);
+    SetPoint(&p[3], p4.x, p4.y);
+
+    if (line_thickness == 1) {
+        SetDCPenColor(dc, color);
+    }
+    else {
+        pen = CreatePen(PS_SOLID, line_thickness, color);
+        SelectObject(dc, pen);
+    }
+
+    SetDCBrushColor(dc, OPAQUE);
+    PolyBezier(dc, p, 4);
+
+    if (pen) {
+        SelectObject(dc, GetStockObject(DC_PEN));
+        DeleteObject(pen);
+    }
+}
+
+static void
+nk_gdi_draw_text(HDC dc, short x, short y, unsigned short w, unsigned short h,
+    const char* text, int len, GdiFont* font, struct nk_color cbg, struct nk_color cfg)
+{
+    int wsize;
+    WCHAR* wstr;
+
+    if (!text || !font || !len) return;
+
+    wsize = MultiByteToWideChar(CP_UTF8, 0, text, len, NULL, 0);
+    wstr = (WCHAR*)_alloca(wsize * sizeof(wchar_t));
+    MultiByteToWideChar(CP_UTF8, 0, text, len, wstr, wsize);
+
+    SetBkColor(dc, convert_color(cbg));
+    SetTextColor(dc, convert_color(cfg));
+
+    SelectObject(dc, font->handle);
+    ExtTextOutW(dc, x, y, ETO_OPAQUE, NULL, wstr, wsize, NULL);
+}
+
+static void
+nk_gdi_clear(nk_gdi_ctx gdi, HDC dc, struct nk_color col)
+{
+    COLORREF color = convert_color(col);
+    RECT rect;
+    SetRect(&rect, 0, 0, gdi->width, gdi->height);
+    SetBkColor(dc, color);
+
+    ExtTextOutW(dc, 0, 0, ETO_OPAQUE, &rect, NULL, 0, NULL);
+}
+
+static void
+nk_gdi_blit(nk_gdi_ctx gdi, HDC dc)
+{
+    BitBlt(dc, 0, 0, gdi->width, gdi->height, gdi->memory_dc, 0, 0, SRCCOPY);
+
+}
+
+GdiFont*
+nk_gdifont_create(const char* name, int size)
+{
+    TEXTMETRICW metric;
+    GdiFont* font = (GdiFont*)calloc(1, sizeof(GdiFont));
+    if (!font)
+        return NULL;
+    font->dc = CreateCompatibleDC(0);
+    font->handle = CreateFontA(size, 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, CLEARTYPE_QUALITY, DEFAULT_PITCH | FF_DONTCARE, name);
+    SelectObject(font->dc, font->handle);
+    GetTextMetricsW(font->dc, &metric);
+    font->height = metric.tmHeight;
+    return font;
+}
+
+static float
+nk_gdifont_get_text_width(nk_handle handle, float height, const char* text, int len)
+{
+    GdiFont* font = (GdiFont*)handle.ptr;
+    SIZE size;
+    int wsize;
+    WCHAR* wstr;
+    if (!font || !text)
+        return 0;
+
+    wsize = MultiByteToWideChar(CP_UTF8, 0, text, len, NULL, 0);
+    wstr = (WCHAR*)_alloca(wsize * sizeof(wchar_t));
+    MultiByteToWideChar(CP_UTF8, 0, text, len, wstr, wsize);
+    if (GetTextExtentPoint32W(font->dc, wstr, wsize, &size))
+        return (float)size.cx;
+    return -1.0f;
+}
+
+void
+nk_gdifont_del(GdiFont* font)
+{
+    if (!font) return;
+    DeleteObject(font->handle);
+    DeleteDC(font->dc);
+    free(font);
+}
+
+static void
+nk_gdi_clipboard_paste(nk_handle usr, struct nk_text_edit* edit)
+{
+    (void)usr;
+    if (IsClipboardFormatAvailable(CF_UNICODETEXT) && OpenClipboard(NULL))
+    {
+        HGLOBAL mem = GetClipboardData(CF_UNICODETEXT);
+        if (mem)
+        {
+            SIZE_T size = GlobalSize(mem) - 1;
+            if (size)
+            {
+                LPCWSTR wstr = (LPCWSTR)GlobalLock(mem);
+                if (wstr)
+                {
+                    int utf8size = WideCharToMultiByte(CP_UTF8, 0, wstr, (int)(size / sizeof(wchar_t)), NULL, 0, NULL, NULL);
+                    if (utf8size)
+                    {
+                        char* utf8 = (char*)malloc(utf8size);
+                        if (utf8)
+                        {
+                            WideCharToMultiByte(CP_UTF8, 0, wstr, (int)(size / sizeof(wchar_t)), utf8, utf8size, NULL, NULL);
+                            nk_textedit_paste(edit, utf8, utf8size);
+                            free(utf8);
+                        }
+                    }
+                    GlobalUnlock(mem);
+                }
+            }
+        }
+        CloseClipboard();
+    }
+}
+
+static void
+nk_gdi_clipboard_copy(nk_handle usr, const char* text, int len)
+{
+    if (OpenClipboard(NULL))
+    {
+        int wsize = MultiByteToWideChar(CP_UTF8, 0, text, len, NULL, 0);
+        if (wsize)
+        {
+            HGLOBAL mem = (HGLOBAL)GlobalAlloc(GMEM_MOVEABLE, (wsize + 1) * sizeof(wchar_t));
+            if (mem)
+            {
+                wchar_t* wstr = (wchar_t*)GlobalLock(mem);
+                if (wstr)
+                {
+                    MultiByteToWideChar(CP_UTF8, 0, text, len, wstr, wsize);
+                    wstr[wsize] = 0;
+                    GlobalUnlock(mem);
+
+                    SetClipboardData(CF_UNICODETEXT, mem);
+                }
+            }
+        }
+        CloseClipboard();
+    }
+}
+
+NK_API struct nk_context*
+nk_gdi_init(nk_gdi_ctx* gdi, GdiFont* gdifont, HDC window_dc, unsigned int width, unsigned int height)
+{
+    *gdi = (nk_gdi_ctx)malloc(sizeof(struct _nk_gdi_ctx));
+
+    struct nk_user_font* font = &gdifont->nk;
+    font->userdata = nk_handle_ptr(gdifont);
+    font->height = (float)gdifont->height;
+    font->width = nk_gdifont_get_text_width;
+
+    (*gdi)->bitmap = CreateCompatibleBitmap(window_dc, width, height);
+    (*gdi)->window_dc = window_dc;
+    (*gdi)->memory_dc = CreateCompatibleDC(window_dc);
+    (*gdi)->width = width;
+    (*gdi)->height = height;
+    SelectObject((*gdi)->memory_dc, (*gdi)->bitmap);
+
+    nk_init_default(&(*gdi)->ctx, font);
+    (*gdi)->ctx.clip.copy = nk_gdi_clipboard_copy;
+    (*gdi)->ctx.clip.paste = nk_gdi_clipboard_paste;
+    return &(*gdi)->ctx;
+}
+
+NK_API void
+nk_gdi_set_font(nk_gdi_ctx gdi, GdiFont* gdifont)
+{
+    struct nk_user_font* font = &gdifont->nk;
+    font->userdata = nk_handle_ptr(gdifont);
+    font->height = (float)gdifont->height;
+    font->width = nk_gdifont_get_text_width;
+    nk_style_set_font(&gdi->ctx, font);
+}
+
+NK_API int
+nk_gdi_handle_event(nk_gdi_ctx gdi, HWND wnd, UINT msg, WPARAM wparam, LPARAM lparam)
+{
+    switch (msg)
+    {
+    case WM_SIZE:
+    {
+        unsigned width = LOWORD(lparam);
+        unsigned height = HIWORD(lparam);
+        if (width != gdi->width || height != gdi->height)
+        {
+            DeleteObject(gdi->bitmap);
+            gdi->bitmap = CreateCompatibleBitmap(gdi->window_dc, width, height);
+            gdi->width = width;
+            gdi->height = height;
+            SelectObject(gdi->memory_dc, gdi->bitmap);
+        }
+        break;
+    }
+
+    case WM_PAINT:
+    {
+        PAINTSTRUCT paint;
+        HDC dc = BeginPaint(wnd, &paint);
+        nk_gdi_blit(gdi, dc);
+        EndPaint(wnd, &paint);
+        return 1;
+    }
+
+    case WM_KEYDOWN:
+    case WM_KEYUP:
+    case WM_SYSKEYDOWN:
+    case WM_SYSKEYUP:
+    {
+        int down = !((lparam >> 31) & 1);
+        int ctrl = GetKeyState(VK_CONTROL) & (1 << 15);
+
+        switch (wparam)
+        {
+        case VK_SHIFT:
+        case VK_LSHIFT:
+        case VK_RSHIFT:
+            nk_input_key(&gdi->ctx, NK_KEY_SHIFT, down);
+            return 1;
+
+        case VK_DELETE:
+            nk_input_key(&gdi->ctx, NK_KEY_DEL, down);
+            return 1;
+
+        case VK_RETURN:
+            nk_input_key(&gdi->ctx, NK_KEY_ENTER, down);
+            return 1;
+
+        case VK_TAB:
+            nk_input_key(&gdi->ctx, NK_KEY_TAB, down);
+            return 1;
+
+        case VK_LEFT:
+            if (ctrl)
+                nk_input_key(&gdi->ctx, NK_KEY_TEXT_WORD_LEFT, down);
+            else
+                nk_input_key(&gdi->ctx, NK_KEY_LEFT, down);
+            return 1;
+
+        case VK_RIGHT:
+            if (ctrl)
+                nk_input_key(&gdi->ctx, NK_KEY_TEXT_WORD_RIGHT, down);
+            else
+                nk_input_key(&gdi->ctx, NK_KEY_RIGHT, down);
+            return 1;
+
+        case VK_BACK:
+            nk_input_key(&gdi->ctx, NK_KEY_BACKSPACE, down);
+            return 1;
+
+        case VK_HOME:
+            nk_input_key(&gdi->ctx, NK_KEY_TEXT_START, down);
+            nk_input_key(&gdi->ctx, NK_KEY_SCROLL_START, down);
+            return 1;
+
+        case VK_END:
+            nk_input_key(&gdi->ctx, NK_KEY_TEXT_END, down);
+            nk_input_key(&gdi->ctx, NK_KEY_SCROLL_END, down);
+            return 1;
+
+        case VK_NEXT:
+            nk_input_key(&gdi->ctx, NK_KEY_SCROLL_DOWN, down);
+            return 1;
+
+        case VK_PRIOR:
+            nk_input_key(&gdi->ctx, NK_KEY_SCROLL_UP, down);
+            return 1;
+
+        case 'C':
+            if (ctrl) {
+                nk_input_key(&gdi->ctx, NK_KEY_COPY, down);
+                return 1;
+            }
+            break;
+
+        case 'V':
+            if (ctrl) {
+                nk_input_key(&gdi->ctx, NK_KEY_PASTE, down);
+                return 1;
+            }
+            break;
+
+        case 'X':
+            if (ctrl) {
+                nk_input_key(&gdi->ctx, NK_KEY_CUT, down);
+                return 1;
+            }
+            break;
+
+        case 'Z':
+            if (ctrl) {
+                nk_input_key(&gdi->ctx, NK_KEY_TEXT_UNDO, down);
+                return 1;
+            }
+            break;
+
+        case 'R':
+            if (ctrl) {
+                nk_input_key(&gdi->ctx, NK_KEY_TEXT_REDO, down);
+                return 1;
+            }
+            break;
+        }
+        return 0;
+    }
+
+    case WM_CHAR:
+        if (wparam >= 32)
+        {
+            nk_input_unicode(&gdi->ctx, (nk_rune)wparam);
+            return 1;
+        }
+        break;
+
+    case WM_LBUTTONDOWN:
+        nk_input_button(&gdi->ctx, NK_BUTTON_LEFT, (short)LOWORD(lparam), (short)HIWORD(lparam), 1);
+        SetCapture(wnd);
+        return 1;
+
+    case WM_LBUTTONUP:
+        nk_input_button(&gdi->ctx, NK_BUTTON_DOUBLE, (short)LOWORD(lparam), (short)HIWORD(lparam), 0);
+        nk_input_button(&gdi->ctx, NK_BUTTON_LEFT, (short)LOWORD(lparam), (short)HIWORD(lparam), 0);
+        ReleaseCapture();
+        return 1;
+
+    case WM_RBUTTONDOWN:
+        nk_input_button(&gdi->ctx, NK_BUTTON_RIGHT, (short)LOWORD(lparam), (short)HIWORD(lparam), 1);
+        SetCapture(wnd);
+        return 1;
+
+    case WM_RBUTTONUP:
+        nk_input_button(&gdi->ctx, NK_BUTTON_RIGHT, (short)LOWORD(lparam), (short)HIWORD(lparam), 0);
+        ReleaseCapture();
+        return 1;
+
+    case WM_MBUTTONDOWN:
+        nk_input_button(&gdi->ctx, NK_BUTTON_MIDDLE, (short)LOWORD(lparam), (short)HIWORD(lparam), 1);
+        SetCapture(wnd);
+        return 1;
+
+    case WM_MBUTTONUP:
+        nk_input_button(&gdi->ctx, NK_BUTTON_MIDDLE, (short)LOWORD(lparam), (short)HIWORD(lparam), 0);
+        ReleaseCapture();
+        return 1;
+
+    case WM_MOUSEWHEEL:
+        nk_input_scroll(&gdi->ctx, nk_vec2(0, (float)(short)HIWORD(wparam) / WHEEL_DELTA));
+        return 1;
+
+    case WM_MOUSEMOVE:
+        nk_input_motion(&gdi->ctx, (short)LOWORD(lparam), (short)HIWORD(lparam));
+        return 1;
+
+    case WM_LBUTTONDBLCLK:
+        nk_input_button(&gdi->ctx, NK_BUTTON_DOUBLE, (short)LOWORD(lparam), (short)HIWORD(lparam), 1);
+        return 1;
+    }
+
+    return 0;
+}
+
+NK_API void
+nk_gdi_shutdown(nk_gdi_ctx gdi)
+{
+    DeleteObject(gdi->memory_dc);
+    DeleteObject(gdi->bitmap);
+    nk_free(&gdi->ctx);
+}
+
+NK_API void
+nk_gdi_render(nk_gdi_ctx gdi, struct nk_color clear)
+{
+    const struct nk_command* cmd;
+
+    HDC memory_dc = gdi->memory_dc;
+    SelectObject(memory_dc, GetStockObject(DC_PEN));
+    SelectObject(memory_dc, GetStockObject(DC_BRUSH));
+    nk_gdi_clear(gdi, memory_dc, clear);
+
+    nk_foreach(cmd, &gdi->ctx)
+    {
+        switch (cmd->type) {
+        case NK_COMMAND_NOP: break;
+        case NK_COMMAND_SCISSOR: {
+            const struct nk_command_scissor* s = (const struct nk_command_scissor*)cmd;
+            nk_gdi_scissor(memory_dc, s->x, s->y, s->w, s->h);
+        } break;
+        case NK_COMMAND_LINE: {
+            const struct nk_command_line* l = (const struct nk_command_line*)cmd;
+            nk_gdi_stroke_line(memory_dc, l->begin.x, l->begin.y, l->end.x,
+                l->end.y, l->line_thickness, l->color);
+        } break;
+        case NK_COMMAND_RECT: {
+            const struct nk_command_rect* r = (const struct nk_command_rect*)cmd;
+            nk_gdi_stroke_rect(memory_dc, r->x, r->y, r->w, r->h,
+                (unsigned short)r->rounding, r->line_thickness, r->color);
+        } break;
+        case NK_COMMAND_RECT_FILLED: {
+            const struct nk_command_rect_filled* r = (const struct nk_command_rect_filled*)cmd;
+            nk_gdi_fill_rect(memory_dc, r->x, r->y, r->w, r->h,
+                (unsigned short)r->rounding, r->color);
+        } break;
+        case NK_COMMAND_CIRCLE: {
+            const struct nk_command_circle* c = (const struct nk_command_circle*)cmd;
+            nk_gdi_stroke_circle(memory_dc, c->x, c->y, c->w, c->h, c->line_thickness, c->color);
+        } break;
+        case NK_COMMAND_CIRCLE_FILLED: {
+            const struct nk_command_circle_filled* c = (const struct nk_command_circle_filled*)cmd;
+            nk_gdi_fill_circle(memory_dc, c->x, c->y, c->w, c->h, c->color);
+        } break;
+        case NK_COMMAND_TRIANGLE: {
+            const struct nk_command_triangle* t = (const struct nk_command_triangle*)cmd;
+            nk_gdi_stroke_triangle(memory_dc, t->a.x, t->a.y, t->b.x, t->b.y,
+                t->c.x, t->c.y, t->line_thickness, t->color);
+        } break;
+        case NK_COMMAND_TRIANGLE_FILLED: {
+            const struct nk_command_triangle_filled* t = (const struct nk_command_triangle_filled*)cmd;
+            nk_gdi_fill_triangle(memory_dc, t->a.x, t->a.y, t->b.x, t->b.y,
+                t->c.x, t->c.y, t->color);
+        } break;
+        case NK_COMMAND_POLYGON: {
+            const struct nk_command_polygon* p = (const struct nk_command_polygon*)cmd;
+            nk_gdi_stroke_polygon(memory_dc, p->points, p->point_count, p->line_thickness, p->color);
+        } break;
+        case NK_COMMAND_POLYGON_FILLED: {
+            const struct nk_command_polygon_filled* p = (const struct nk_command_polygon_filled*)cmd;
+            nk_gdi_fill_polygon(memory_dc, p->points, p->point_count, p->color);
+        } break;
+        case NK_COMMAND_POLYLINE: {
+            const struct nk_command_polyline* p = (const struct nk_command_polyline*)cmd;
+            nk_gdi_stroke_polyline(memory_dc, p->points, p->point_count, p->line_thickness, p->color);
+        } break;
+        case NK_COMMAND_TEXT: {
+            const struct nk_command_text* t = (const struct nk_command_text*)cmd;
+            nk_gdi_draw_text(memory_dc, t->x, t->y, t->w, t->h,
+                (const char*)t->string, t->length,
+                (GdiFont*)t->font->userdata.ptr,
+                t->background, t->foreground);
+        } break;
+        case NK_COMMAND_CURVE: {
+            const struct nk_command_curve* q = (const struct nk_command_curve*)cmd;
+            nk_gdi_stroke_curve(memory_dc, q->begin, q->ctrl[0], q->ctrl[1],
+                q->end, q->line_thickness, q->color);
+        } break;
+        case NK_COMMAND_RECT_MULTI_COLOR: {
+            const struct nk_command_rect_multi_color* r = (const struct nk_command_rect_multi_color*)cmd;
+            nk_gdi_rect_multi_color(gdi, memory_dc, r->x, r->y, r->w, r->h, r->left, r->top, r->right, r->bottom);
+        } break;
+        case NK_COMMAND_IMAGE: {
+            const struct nk_command_image* i = (const struct nk_command_image*)cmd;
+            nk_gdi_draw_image(gdi, i->x, i->y, i->w, i->h, i->img, i->col);
+        } break;
+        case NK_COMMAND_ARC:
+        case NK_COMMAND_ARC_FILLED:
+        default: break;
+        }
+    }
+    nk_gdi_blit(gdi, gdi->window_dc);
+    nk_clear(&gdi->ctx);
+}
+
+#endif

demo/gdi_native_nuklear/window.h

@@ -0,0 +1,377 @@
+#pragma once
+
+namespace NkGdi
+{
+    // Container for window management
+    class WindowClass
+    {
+        public:
+            // Public exposed name
+            static const wchar_t* const ClassName;
+
+            WindowClass(const WindowClass&) = delete;
+        private:
+            // Instance
+            static WindowClass ClassInstance;
+
+            // Sigelton
+            WindowClass();
+    };
+
+    // Window base class
+    class Window
+    {
+        friend class WindowClass;
+
+        public:
+            // Default constructs
+            Window() = default;
+            Window(const Window&) = delete;
+            Window(Window&&) = default;
+            // Constructor
+            Window(unsigned int width, unsigned int height, const char* name, int posX = 100, int posY = 100);
+            // Destructor
+            ~Window();
+
+            // Processs window events and render the window (returns true as long as window is open)
+            bool Update();
+
+            // Properties
+            bool AllowSizing = true;
+            bool AllowMaximize = true;
+            bool AllowMove = true;
+            bool HasTitlebar = true;
+
+        public:
+            // Called when the core window gets an event
+            virtual LRESULT OnWindowMessage(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam);
+
+            // Called when the window is created
+            inline virtual void OnCreate() {};
+            // Called when the window is destroyed
+            inline virtual void OnDestroy() {};
+            // Called when the windows is beein updated (before events are served)
+            inline virtual void OnUpdate() {};
+            // Called when the window is beeing closed by the user (return false to abort)
+            inline virtual bool OnClose() { return true; };
+            // Called when nuklear drawcalls can be issued (return false to close the window)
+            inline virtual bool OnDraw(nk_context* ctx) { return true; };
+
+        private:
+            // Static window procs
+            static LRESULT wndProcSetup(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam);
+            static LRESULT wndProcRun(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam);
+
+        private:
+            // Window handle
+            HWND m_window = NULL;
+
+            // Nuklear context
+            nk_gdi_ctx m_nkGdiCtx = nullptr;
+            nk_context* m_nkCtx = nullptr;
+
+            // Nuklear objects
+            GdiFont* m_gdiFont = nullptr;
+            HDC m_windowDc = NULL;
+
+            // Window runtime features
+            bool m_isOpen = true;
+            bool m_isDraggin = false;
+            bool m_wsOverride = false;
+            bool m_isMaximized = false;
+            POINT m_dragOffset = {};
+            int m_width = 0;
+            int m_height = 0;
+    };
+}
+
+#ifdef NKGDI_IMPLEMENT_WINDOW
+
+const wchar_t* const NkGdi::WindowClass::ClassName = L"WNDCLS_NkGdi";
+NkGdi::WindowClass NkGdi::WindowClass::ClassInstance;
+
+NkGdi::WindowClass::WindowClass()
+{
+    // Describe class
+    WNDCLASSEXW cls;
+    cls.cbSize = sizeof(WNDCLASSEXW);
+    cls.style = CS_OWNDC | CS_DBLCLKS;
+    cls.lpfnWndProc = &Window::wndProcSetup;
+    cls.cbClsExtra = 0;
+    cls.cbWndExtra = 0;
+    cls.hInstance = GetModuleHandle(NULL);
+    cls.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    cls.hCursor = LoadCursor(NULL, IDC_ARROW);
+    cls.hbrBackground = NULL;
+    cls.lpszMenuName = nullptr;
+    cls.lpszClassName = ClassName;
+    cls.hIconSm = NULL;
+
+    // Register class
+    RegisterClassExW(&cls);
+}
+
+NkGdi::Window::Window(unsigned int width, unsigned int height, const char* name, int posX, int posY)
+{
+    DWORD styleEx = WS_EX_WINDOWEDGE;
+    DWORD style = WS_POPUP;
+
+    // Compute window size
+    RECT cr;
+    cr.left = 0;
+    cr.top = 0;
+    cr.right = width;
+    cr.bottom = height;
+    AdjustWindowRectEx(&cr, style, FALSE, styleEx);
+
+    // Create the window
+    m_window = CreateWindowExW(
+        styleEx,
+        WindowClass::ClassName,
+        L"NkGdi",
+        style | WS_VISIBLE,
+        posX, posY,
+        cr.right - cr.left, cr.bottom - cr.top,
+        NULL, NULL,
+        GetModuleHandleW(nullptr),
+        this
+    );
+ 
+    // Rename window to user picked name
+    SetWindowTextA(m_window, name);
+
+    // Get DC
+    m_windowDc = GetWindowDC(m_window);
+
+    // Create font
+    m_gdiFont = nk_gdifont_create("Arial", 16);
+    m_nkCtx = nk_gdi_init(&m_nkGdiCtx, m_gdiFont, m_windowDc, width, height);
+}
+
+NkGdi::Window::~Window()
+{
+    // Destroy  GDI context
+    if (m_nkGdiCtx)
+    {
+        nk_gdi_shutdown(m_nkGdiCtx);
+    }
+
+    // Destroy font
+    if (m_gdiFont)
+    {
+        nk_gdifont_del(m_gdiFont);
+    }
+
+    // Close DC
+    if (m_windowDc)
+    {
+        ReleaseDC(m_window, m_windowDc);
+    }
+
+    // Destroy window
+    if (m_window)
+    {
+        CloseWindow(m_window);
+        DestroyWindow(m_window);
+    }
+}
+
+bool NkGdi::Window::Update()
+{
+    // Only process events while window is open
+    if (m_isOpen)
+    {
+        // Notify class that event processing has stated
+        OnUpdate();
+
+        // Windows event loop
+        MSG msg = {};
+        nk_input_begin(m_nkCtx);
+        while (PeekMessage(&msg, m_window, 0, 0, PM_REMOVE))
+        {
+            TranslateMessage(&msg);
+            DispatchMessageW(&msg);
+        }
+        nk_input_end(m_nkCtx);
+
+        // Get title
+        char title[1024];
+        GetWindowTextA(m_window, title, 1024);
+
+        // Window body
+        if (m_wsOverride)
+            nk_window_set_bounds(m_nkCtx, title, nk_rect(0, 0, m_width, m_height));
+        if (nk_begin(m_nkCtx, title, nk_rect(0, 0, m_width, m_height), 
+            NK_WINDOW_BORDER | 
+            (HasTitlebar ? NK_WINDOW_CLOSABLE | NK_WINDOW_TITLE : NULL) |
+            (m_isMaximized || !AllowSizing ? NULL : NK_WINDOW_SCALABLE) 
+        ))
+        {
+            if(!OnDraw(m_nkCtx))
+                m_isOpen = false;
+
+            // Update window size
+            struct nk_rect bounds = nk_window_get_bounds(m_nkCtx);
+            if(bounds.w != m_width || bounds.h != m_height)
+                SetWindowPos(m_window, NULL, 0, 0, bounds.w, bounds.h, SWP_NOMOVE | SWP_NOOWNERZORDER);
+        }
+        else
+        {
+            // Handle window closing
+            if(OnClose())
+                m_isOpen = false;
+        }
+        nk_end(m_nkCtx);
+        m_wsOverride = false;
+
+        // Final render pass
+        nk_gdi_render(m_nkGdiCtx, nk_rgb(30, 30, 30));
+    }
+
+    return m_isOpen;
+}
+
+LRESULT NkGdi::Window::OnWindowMessage(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    // Switch on supplied message code
+    switch (msg)
+    {
+        // Close event
+        case WM_CLOSE:
+            if (OnClose())
+                m_isOpen = false;
+            return 0; // Will always be handled internaly
+        
+        // While sizing
+        case WM_SIZING:
+            {
+            RECT cr;
+            GetClientRect(wnd, &cr);
+            m_width = cr.right - cr.left;
+            m_height = cr.bottom - cr.top;
+            }
+            break;
+
+        // When sized
+        case WM_SIZE:
+            {
+            // Adjust maximize properties
+            if (wParam == SIZE_MAXIMIZED)
+            {
+                HMONITOR monitor = MonitorFromWindow(wnd, MONITOR_DEFAULTTOPRIMARY);
+                MONITORINFO monitorInfo;
+                monitorInfo.cbSize = sizeof(MONITORINFO);
+                if (GetMonitorInfoW(monitor, &monitorInfo))
+                {
+                    m_height = monitorInfo.rcWork.bottom - monitorInfo.rcWork.top;
+                    m_width = monitorInfo.rcWork.right - monitorInfo.rcWork.left;
+                    m_wsOverride = true;
+                    m_isMaximized = true;
+                    SetWindowPos(wnd, NULL, 0, 0, m_width, m_height, SWP_NOMOVE | SWP_NOZORDER);
+                }
+            }
+            else if (wParam == SIZE_RESTORED)
+            {
+                m_isMaximized = false;
+            }
+
+            // Compute new bounds
+            RECT cr;
+            GetClientRect(wnd, &cr);
+            m_width = cr.right - cr.left;
+            m_height = cr.bottom - cr.top;
+            }
+            break;
+
+        // When mouse start l-press (drag window)
+        case WM_LBUTTONDOWN:
+            {
+            if (HIWORD(lParam) <= 30 && AllowMove)
+            {
+                // Start dragging
+                m_isDraggin = true;
+                m_dragOffset.x = LOWORD(lParam);
+                m_dragOffset.y = HIWORD(lParam);
+            }
+            }
+            break;
+
+        // When mouse stops l-press (drag window)
+        case WM_LBUTTONUP:
+            m_isDraggin = false;
+            break;
+
+        // Mouse movement (dragging)
+        case WM_MOUSEMOVE:
+            {
+            if (m_isDraggin && !m_isMaximized)
+            {
+                // Get mouse postion and substract offset
+                POINT cursorPos;
+                GetCursorPos(&cursorPos);
+                cursorPos.x -= m_dragOffset.x;
+                cursorPos.y -= m_dragOffset.y;
+                // Use as new position
+                ShowWindow(m_window, SW_RESTORE);
+                SetWindowPos(wnd, NULL, cursorPos.x, cursorPos.y, 0, 0, SWP_NOSIZE | SWP_NOZORDER);
+            }
+            }
+            break;
+
+        // On mouse doubble click (maximize)
+        case WM_LBUTTONDBLCLK:
+            {
+            if (HIWORD(lParam) <= 30 && AllowMaximize)
+            {
+                if (m_isMaximized)
+                {
+                    ShowWindow(wnd, SW_RESTORE);
+                }
+                else
+                {
+                    ShowWindow(wnd, SW_MAXIMIZE);
+                }
+                m_wsOverride = true;
+            }
+            }
+            break;
+    }
+
+    // Send to nuklear
+    if (m_nkGdiCtx && nk_gdi_handle_event(m_nkGdiCtx, wnd, msg, wParam, lParam))
+        return 0;
+
+    // In case this is ever reached: Run default behaviour
+    return DefWindowProc(wnd, msg, wParam, lParam);
+}
+
+LRESULT NkGdi::Window::wndProcSetup(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    // Wait for setup message
+    if (msg == WM_NCCREATE)
+    {
+        // Get creation parameters & window pointer
+        CREATESTRUCT* ptrCr = (CREATESTRUCT*)lParam;
+        Window* ptrWindow = (Window*)ptrCr->lpCreateParams;
+
+        // Store pointer and new proc in window
+        SetWindowLongPtr(wnd, GWLP_USERDATA, (LONG_PTR)ptrWindow);
+        SetWindowLongPtr(wnd, GWLP_WNDPROC, (LONG_PTR)&wndProcRun);
+
+        // Handled by window
+        return ptrWindow->OnWindowMessage(wnd, msg, wParam, lParam);
+    }
+
+    // Default handler
+    return DefWindowProc(wnd, msg, wParam, lParam);
+}
+
+LRESULT NkGdi::Window::wndProcRun(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    // Get window pointer
+    Window* ptrWindow = (Window*)GetWindowLongPtr(wnd, GWLP_USERDATA);
+    // Call window
+    return ptrWindow->OnWindowMessage(wnd, msg, wParam, lParam);
+}
+
+#endif