Added pure X11/OpenGL demo

demo/x11_opengl3/Makefile

@@ -0,0 +1,26 @@
+# Install
+BIN = demo
+
+# Compiler
+CC = clang
+DCC = gcc
+
+# Flags
+CFLAGS = -std=c99 -pedantic -O2
+
+SRC = main.c
+OBJ = $(SRC:.c=.o)
+
+# Modes
+.PHONY: gcc
+gcc: CC = gcc
+gcc: $(BIN)
+
+.PHONY: clang
+clang: CC = clang
+clang: $(BIN)
+
+$(BIN):
+	@mkdir -p bin
+	rm -f bin/$(BIN) $(OBJS)
+	$(CC) $(SRC) $(CFLAGS) -o bin/$(BIN) -lX11 -lm -lGL -lm -lGLU

demo/x11_opengl3/main.c

@@ -0,0 +1,302 @@
+/* nuklear - v1.00 - public domain */
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <string.h>
+#include <math.h>
+#include <assert.h>
+#include <math.h>
+#include <time.h>
+#include <limits.h>
+
+/* these defines are both needed for the header
+ * and source file. So if you split them remember
+ * to copy them as well. */
+#define NK_INCLUDE_FIXED_TYPES
+#define NK_INCLUDE_STANDARD_IO
+#define NK_INCLUDE_DEFAULT_ALLOCATOR
+#define NK_INCLUDE_VERTEX_BUFFER_OUTPUT
+#define NK_INCLUDE_FONT_BAKING
+#define NK_INCLUDE_DEFAULT_FONT
+#include "nuklear_x11.h"
+#include "nuklear_x11.c"
+
+#define WINDOW_WIDTH 800
+#define WINDOW_HEIGHT 600
+
+#define MAX_VERTEX_BUFFER 512 * 1024
+#define MAX_ELEMENT_BUFFER 128 * 1024
+
+#define UNUSED(a) (void)a
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+#define MAX(a,b) ((a) < (b) ? (b) : (a))
+#define LEN(a) (sizeof(a)/sizeof(a)[0])
+
+/* ===============================================================
+ *
+ *                          EXAMPLE
+ *
+ * ===============================================================*/
+/* This are some code examples to provide a small overview of what can be
+ * done with this library. To try out an example uncomment the include
+ * and the corresponding function. */
+/*#include "../style.c"*/
+/*#include "../calculator.c"*/
+/*#include "../overview.c"*/
+/*#include "../node_editor.c"*/
+
+/* ===============================================================
+ *
+ *                          DEMO
+ *
+ * ===============================================================*/
+struct XWindow {
+    Display *dpy;
+    Window win;
+    XVisualInfo *vis;
+    Colormap cmap;
+    XSetWindowAttributes swa;
+    XWindowAttributes attr;
+    GLXFBConfig fbc;
+    int width, height;
+};
+static int gl_err = FALSE;
+static int gl_error_handler(Display *dpy, XErrorEvent *ev)
+{UNUSED((dpy, ev)); gl_err = TRUE;return 0;}
+
+static void
+die(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    va_end(ap);
+    fputs("\n", stderr);
+    exit(EXIT_FAILURE);
+}
+
+static int
+has_extension(const char *string, const char *ext)
+{
+    const char *start, *where, *term;
+    where = strchr(ext, ' ');
+    if (where || *ext == '\0')
+        return FALSE;
+
+    for (start = string;;) {
+        where = strstr((const char*)start, ext);
+        if (!where) break;
+        term = where + strlen(ext);
+        if (where == start || *(where - 1) == ' ') {
+            if (*term == ' ' || *term == '\0')
+                return TRUE;
+        }
+        start = term;
+    }
+    return FALSE;
+}
+
+int main(int argc, char **argv)
+{
+    /* Platform */
+    int running = 1;
+    struct XWindow win;
+    GLXContext glContext;
+    struct nk_context *ctx;
+    struct nk_color background;
+
+    memset(&win, 0, sizeof(win));
+    win.dpy = XOpenDisplay(NULL);
+    if (!win.dpy) die("Failed to open X display\n");
+    {
+        /* check glx version */
+        int glx_major, glx_minor;
+        if (!glXQueryVersion(win.dpy, &glx_major, &glx_minor))
+            die("[X11]: Error: Failed to query OpenGL version\n");
+        if ((glx_major == 1 && glx_minor < 3) || (glx_major < 1))
+            die("[X11]: Error: Invalid GLX version!\n");
+    }
+    {
+        /* find and pick matching framebuffer visual */
+        int fb_count;
+        static GLint attr[] = {
+            GLX_X_RENDERABLE,   True,
+            GLX_DRAWABLE_TYPE,  GLX_WINDOW_BIT,
+            GLX_RENDER_TYPE,    GLX_RGBA_BIT,
+            GLX_X_VISUAL_TYPE,  GLX_TRUE_COLOR,
+            GLX_RED_SIZE,       8,
+            GLX_GREEN_SIZE,     8,
+            GLX_BLUE_SIZE,      8,
+            GLX_ALPHA_SIZE,     8,
+            GLX_DEPTH_SIZE,     24,
+            GLX_STENCIL_SIZE,   8,
+            GLX_DOUBLEBUFFER,   True,
+            None
+        };
+        GLXFBConfig *fbc;
+        fbc = glXChooseFBConfig(win.dpy, DefaultScreen(win.dpy), attr, &fb_count);
+        if (!fbc) die("[X11]: Error: failed to retrieve framebuffer configuration\n");
+        {
+            /* pick framebuffer with most samples per pixel */
+            int i;
+            int fb_best = -1, best_num_samples = -1;
+            for (i = 0; i < fb_count; ++i) {
+                XVisualInfo *vi = glXGetVisualFromFBConfig(win.dpy, fbc[i]);
+                if (vi) {
+                    int sample_buffer, samples;
+                    glXGetFBConfigAttrib(win.dpy, fbc[i], GLX_SAMPLE_BUFFERS, &sample_buffer);
+                    glXGetFBConfigAttrib(win.dpy, fbc[i], GLX_SAMPLES, &samples);
+                    if ((fb_best < 0) || (sample_buffer && samples > best_num_samples))
+                        fb_best = i; best_num_samples = samples;
+                }
+            }
+            win.fbc = fbc[fb_best];
+            XFree(fbc);
+            win.vis = glXGetVisualFromFBConfig(win.dpy, win.fbc);
+        }
+    }
+    {
+        /* create window */
+        win.cmap = XCreateColormap(win.dpy, RootWindow(win.dpy, win.vis->screen), win.vis->visual, AllocNone);
+        win.swa.colormap =  win.cmap;
+        win.swa.background_pixmap = None;
+        win.swa.border_pixel = 0;
+        win.swa.event_mask =
+            ExposureMask | KeyPressMask | KeyReleaseMask |
+            ButtonPress | ButtonReleaseMask| ButtonMotionMask |
+            Button1MotionMask | Button3MotionMask | Button4MotionMask | Button5MotionMask|
+            PointerMotionMask| StructureNotifyMask;
+        win.win = XCreateWindow(win.dpy, RootWindow(win.dpy, win.vis->screen), 0, 0,
+            WINDOW_WIDTH, WINDOW_HEIGHT, 0, win.vis->depth, InputOutput,
+            win.vis->visual, CWBorderPixel|CWColormap|CWEventMask, &win.swa);
+        if (!win.win) die("[X11]: Failed to create window\n");
+        XFree(win.vis);
+        XStoreName(win.dpy, win.win, "Demo");
+        XMapWindow(win.dpy, win.win);
+    }
+    {
+        /* create opengl context */
+        typedef GLXContext(*glxCreateContext)(Display*, GLXFBConfig, GLXContext, Bool, const int*);
+        int(*old_handler)(Display*, XErrorEvent*) = XSetErrorHandler(gl_error_handler);
+        const char *extensions_str = glXQueryExtensionsString(win.dpy, DefaultScreen(win.dpy));
+        glxCreateContext create_context = (glxCreateContext)
+            glXGetProcAddressARB((const GLubyte*)"glXCreateContextAttribsARB");
+
+        gl_err = FALSE;
+        if (!has_extension(extensions_str, "GLX_ARB_create_context") || !create_context) {
+            fprintf(stdout, "[X11]: glXCreateContextAttribARB() not found...\n");
+            fprintf(stdout, "[X11]: ... using old-style GLX context\n");
+            glContext = glXCreateNewContext(win.dpy, win.fbc, GLX_RGBA_TYPE, 0, True);
+        } else {
+            GLint attr[] = {
+                GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
+                GLX_CONTEXT_MINOR_VERSION_ARB, 0,
+                None
+            };
+            glContext = create_context(win.dpy, win.fbc, 0, True, attr);
+            XSync(win.dpy, False);
+            if (gl_err || !glContext) {
+                /* Could not create GL 3.0 context. Fallback to old 2.x context.
+                 * If a version below 3.0 is requested, implementations will
+                 * return the newest context version compatible with OpenGL
+                 * version less than version 3.0.*/
+                attr[1] = 1; attr[3] = 0;
+                gl_err = FALSE;
+                fprintf(stdout, "[X11] Failed to create OpenGL 3.0 context\n");
+                fprintf(stdout, "[X11] ... using old-style GLX context!\n");
+                glContext = create_context(win.dpy, win.fbc, 0, True, attr);
+            }
+        }
+        XSync(win.dpy, False);
+        XSetErrorHandler(old_handler);
+        if (gl_err || !glContext)
+            die("[X11]: Failed to create an OpenGL context\n");
+        glXMakeCurrent(win.dpy, win.win, glContext);
+    }
+
+    ctx = nk_x11_init(win.dpy, win.win);
+    /* Load Fonts: if none of these are loaded a default font will be used  */
+    {struct nk_font_atlas *atlas;
+    nk_x11_font_stash_begin(&atlas);
+    /*struct nk_font *droid = nk_font_atlas_add_from_file(atlas, "../../../extra_font/DroidSans.ttf", 14, 0);*/
+    /*struct nk_font *roboto = nk_font_atlas_add_from_file(atlas, "../../../extra_font/Roboto-Regular.ttf", 14, 0);*/
+    /*struct nk_font *future = nk_font_atlas_add_from_file(atlas, "../../../extra_font/kenvector_future_thin.ttf", 13, 0);*/
+    /*struct nk_font *clean = nk_font_atlas_add_from_file(atlas, "../../../extra_font/ProggyClean.ttf", 12, 0);*/
+    /*struct nk_font *tiny = nk_font_atlas_add_from_file(atlas, "../../../extra_font/ProggyTiny.ttf", 10, 0);*/
+    /*struct nk_font *cousine = nk_font_atlas_add_from_file(atlas, "../../../extra_font/Cousine-Regular.ttf", 13, 0);*/
+    nk_x11_font_stash_end();
+    /*nk_style_set_font(ctx, &droid->handle);*/}
+
+    /* style.c */
+    /*set_style(ctx, THEME_WHITE);*/
+    /*set_style(ctx, THEME_RED);*/
+    /*set_style(ctx, THEME_BLUE);*/
+    /*set_style(ctx, THEME_DARK);*/
+
+    background = nk_rgb(28,48,62);
+    while (running)
+    {
+        /* Input */
+        XEvent evt;
+        nk_input_begin(ctx);
+        while (XCheckWindowEvent(win.dpy, win.win, win.swa.event_mask, &evt)){
+            if (XFilterEvent(&evt, win.win)) continue;
+            nk_x11_handle_event(&evt);
+        }
+        nk_input_end(ctx);
+
+        /* GUI */
+        {struct nk_panel layout;
+        if (nk_begin(ctx, &layout, "Demo", nk_rect(50, 50, 200, 200),
+            NK_WINDOW_BORDER|NK_WINDOW_MOVABLE|NK_WINDOW_SCALABLE|
+            NK_WINDOW_CLOSABLE|NK_WINDOW_MINIMIZABLE|NK_WINDOW_TITLE))
+        {
+            enum {EASY, HARD};
+            static int op = EASY;
+            static int property = 20;
+
+            nk_layout_row_static(ctx, 30, 80, 1);
+            if (nk_button_label(ctx, "button", NK_BUTTON_DEFAULT))
+                fprintf(stdout, "button pressed\n");
+            nk_layout_row_dynamic(ctx, 30, 2);
+            if (nk_option_label(ctx, "easy", op == EASY)) op = EASY;
+            if (nk_option_label(ctx, "hard", op == HARD)) op = HARD;
+            nk_layout_row_dynamic(ctx, 25, 1);
+            nk_property_int(ctx, "Compression:", 0, &property, 100, 10, 1);
+        }
+        nk_end(ctx);}
+        if (nk_window_is_closed(ctx, "Demo")) break;
+
+        /* -------------- EXAMPLES ---------------- */
+        /*calculator(ctx);*/
+        /*overview(ctx);*/
+        /*node_editor(ctx);*/
+        /* ----------------------------------------- */
+
+        /* Draw */
+        {float bg[4];
+        nk_color_fv(bg, background);
+        XGetWindowAttributes(win.dpy, win.win, &win.attr);
+        glViewport(0, 0, win.width, win.height);
+        glClear(GL_COLOR_BUFFER_BIT);
+        glClearColor(bg[0], bg[1], bg[2], bg[3]);
+        /* IMPORTANT: `nk_x11_render` modifies some global OpenGL state
+         * with blending, scissor, face culling, depth test and viewport and
+         * defaults everything back into a default state.
+         * Make sure to either a.) save and restore or b.) reset your own state after
+         * rendering the UI. */
+        nk_x11_render(NK_ANTI_ALIASING_ON, MAX_VERTEX_BUFFER, MAX_ELEMENT_BUFFER);
+        glXSwapBuffers(win.dpy, win.win);}
+    }
+
+    nk_x11_shutdown();
+    glXMakeCurrent(win.dpy, 0, 0);
+    glXDestroyContext(win.dpy, glContext);
+    XUnmapWindow(win.dpy, win.win);
+    XFreeColormap(win.dpy, win.cmap);
+    XDestroyWindow(win.dpy, win.win);
+    XCloseDisplay(win.dpy);
+    return 0;
+
+}

demo/x11_opengl3/nuklear_x11.c

@@ -0,0 +1,629 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xresource.h>
+#include <X11/Xlocale.h>
+
+#include <GL/gl.h>
+#include <GL/glx.h>
+#include <GL/glext.h>
+#include <GL/glxext.h>
+
+#define NK_IMPLEMENTATION
+#include "nuklear_x11.h"
+#include "../../nuklear.h"
+
+#ifndef FALSE
+#define FALSE 0
+#endif
+#ifndef TRUE
+#define TRUE 1
+#endif
+
+#if NK_X11_LOAD_OPENGL_EXTENSIONS
+/* GL_ARB_vertex_buffer_object */
+typedef void(*qglGenBuffers)(GLsizei, GLuint*);
+typedef void(*qglBindBuffer)(GLenum, GLuint);
+typedef void(*qglBufferData)(GLenum, GLsizeiptr, const GLvoid*, GLenum);
+typedef void(*qglBufferSubData)(GLenum, GLintptr, GLsizeiptr, const GLvoid*);
+typedef void*(*qglMapBuffer)(GLenum, GLenum);
+typedef GLboolean(*qglUnmapBuffer)(GLenum);
+typedef void(*qglDeleteBuffers)(GLsizei, GLuint*);
+/* GL_ARB_vertex_array_object */
+typedef void (*qglGenVertexArrays)(GLsizei, GLuint*);
+typedef void (*qglBindVertexArray)(GLuint);
+typedef void (*qglDeleteVertexArrays)(GLsizei, const GLuint*);
+/* GL_ARB_vertex_program / GL_ARB_fragment_program */
+typedef void(*qglVertexAttribPointer)(GLuint, GLint, GLenum, GLboolean, GLsizei, const GLvoid*);
+typedef void(*qglEnableVertexAttribArray)(GLuint);
+typedef void(*qglDisableVertexAttribArray)(GLuint);
+/* GL_ARB_framebuffer_object */
+typedef void(*qglGenerateMipmap)(GLenum target);
+/* GLSL/OpenGL 2.0 core */
+typedef GLuint(*qglCreateShader)(GLenum);
+typedef void(*qglShaderSource)(GLuint, GLsizei, const GLchar**, const GLint*);
+typedef void(*qglCompileShader)(GLuint);
+typedef void(*qglGetShaderiv)(GLuint, GLenum, GLint*);
+typedef void(*qglGetShaderInfoLog)(GLuint, GLsizei, GLsizei*, GLchar*);
+typedef void(*qglDeleteShader)(GLuint);
+typedef GLuint(*qglCreateProgram)(void);
+typedef void(*qglAttachShader)(GLuint, GLuint);
+typedef void(*qglDetachShader)(GLuint, GLuint);
+typedef void(*qglLinkProgram)(GLuint);
+typedef void(*qglUseProgram)(GLuint);
+typedef void(*qglGetProgramiv)(GLuint, GLenum, GLint*);
+typedef void(*qglGetProgramInfoLog)(GLuint, GLsizei, GLsizei*, GLchar*);
+typedef void(*qglDeleteProgram)(GLuint);
+typedef GLint(*qglGetUniformLocation)(GLuint, const GLchar*);
+typedef GLint(*qglGetAttribLocation)(GLuint, const GLchar*);
+typedef void(*qglUniform1i)(GLint, GLint);
+typedef void(*qglUniform1f)(GLint, GLfloat);
+typedef void(*qglUniformMatrix3fv)(GLint, GLsizei, GLboolean, const GLfloat*);
+typedef void(*qglUniformMatrix4fv)(GLint, GLsizei, GLboolean, const GLfloat*);
+
+static qglGenBuffers glGenBuffers;
+static qglBindBuffer glBindBuffer;
+static qglBufferData glBufferData;
+static qglBufferSubData glBufferSubData;
+static qglMapBuffer glMapBuffer;
+static qglUnmapBuffer glUnmapBuffer;
+static qglDeleteBuffers glDeleteBuffers;
+static qglGenVertexArrays glGenVertexArrays;
+static qglBindVertexArray glBindVertexArray;
+static qglDeleteVertexArrays glDeleteVertexArrays;
+static qglVertexAttribPointer glVertexAttribPointer;
+static qglEnableVertexAttribArray glEnableVertexAttribArray;
+static qglDisableVertexAttribArray glDisableVertexAttribArray;
+static qglGenerateMipmap glGenerateMipmap;
+static qglCreateShader glCreateShader;
+static qglShaderSource glShaderSource;
+static qglCompileShader glCompileShader;
+static qglGetShaderiv glGetShaderiv;
+static qglGetShaderInfoLog glGetShaderInfoLog;
+static qglDeleteShader glDeleteShader;
+static qglCreateProgram glCreateProgram;
+static qglAttachShader glAttachShader;
+static qglDetachShader glDetachShader;
+static qglLinkProgram glLinkProgram;
+static qglUseProgram glUseProgram;
+static qglGetProgramiv glGetProgramiv;
+static qglGetProgramInfoLog glGetProgramInfoLog;
+static qglDeleteProgram glDeleteProgram;
+static qglGetUniformLocation glGetUniformLocation;
+static qglGetAttribLocation glGetAttribLocation;
+static qglUniform1i glUniform1i;
+static qglUniform1f glUniform1f;
+static qglUniformMatrix3fv glUniformMatrix3fv;
+static qglUniformMatrix4fv glUniformMatrix4fv;
+
+enum graphics_card_vendors {
+    VENDOR_UNKNOWN,
+    VENDOR_NVIDIA,
+    VENDOR_AMD,
+    VENDOR_INTEL
+};
+
+struct opengl_info {
+    /* info */
+    const char *vendor_str;
+    const char *version_str;
+    const char *extensions_str;
+    const char *renderer_str;
+    const char *glsl_version_str;
+    enum graphics_card_vendors vendor;
+    /* version */
+    float version;
+    int major_version;
+    int minor_version;
+    /* extensions */
+    int glsl_available;
+    int vertex_buffer_obj_available;
+    int vertex_array_obj_available;
+    int map_buffer_range_available;
+    int fragment_program_available;
+    int frame_buffer_object_available;
+};
+#endif
+
+struct nk_x11_device {
+#if NK_X11_LOAD_OPENGL_EXTENSIONS
+    struct opengl_info info;
+#endif
+    struct nk_buffer cmds;
+    struct nk_draw_null_texture null;
+    GLuint vbo, vao, ebo;
+    GLuint prog;
+    GLuint vert_shdr;
+    GLuint frag_shdr;
+    GLint attrib_pos;
+    GLint attrib_uv;
+    GLint attrib_col;
+    GLint uniform_tex;
+    GLint uniform_proj;
+    GLuint font_tex;
+};
+
+static struct nk_x11 {
+    struct nk_x11_device ogl;
+    struct nk_context ctx;
+    struct nk_font_atlas atlas;
+    Display *dpy;
+    Window win;
+} x11;
+
+#ifdef __APPLE__
+  #define NK_SHADER_VERSION "#version 150\n"
+#else
+  #define NK_SHADER_VERSION "#version 300 es\n"
+#endif
+
+#if NK_X11_LOAD_OPENGL_EXTENSIONS
+NK_INTERN int
+nk_x11_stricmpn(const char *a, const char *b, int len)
+{
+    int i = 0;
+    for (i = 0; i < len && a[i] && b[i]; ++i)
+        if (a[i] != b[i]) return 1;
+    if (i != len) return 1;
+    return 0;
+}
+
+NK_INTERN int
+nk_x11_check_extension(struct opengl_info *GL, const char *ext)
+{
+    const char *start, *where, *term;
+    where = strchr(ext, ' ');
+    if (where || *ext == '\0')
+        return FALSE;
+
+    for (start = GL->extensions_str;;) {
+        where = strstr((const char*)start, ext);
+        if (!where) break;
+        term = where + strlen(ext);
+        if (where == start || *(where - 1) == ' ') {
+            if (*term == ' ' || *term == '\0')
+                return TRUE;
+        }
+        start = term;
+    }
+    return FALSE;
+}
+
+#define GL_EXT(name) (q##name)nk_gl_ext(#name)
+NK_INTERN __GLXextFuncPtr
+nk_gl_ext(const char *name)
+{
+    __GLXextFuncPtr func;
+    func = glXGetProcAddress((const GLubyte*)name);
+    if (!func) {
+        fprintf(stdout, "[GL]: failed to load extension: %s", name);
+        return NULL;
+    }
+    return func;
+}
+
+NK_INTERN int
+nk_load_opengl(struct opengl_info *gl)
+{
+    int failed = FALSE;
+    gl->version_str = (const char*)glGetString(GL_VERSION);
+    glGetIntegerv(GL_MAJOR_VERSION, &gl->major_version);
+    glGetIntegerv(GL_MINOR_VERSION, &gl->minor_version);
+    if (gl->major_version < 2) {
+        fprintf(stderr, "[GL]: Graphics card does not fullfill minimum OpenGL 2.0 support\n");
+        return 0;
+    }
+
+    gl->version = (float)gl->major_version + (float)gl->minor_version * 0.1f;
+    gl->renderer_str = (const char*)glGetString(GL_RENDERER);
+    gl->extensions_str = (const char*)glGetString(GL_EXTENSIONS);
+    gl->glsl_version_str = (const char*)glGetString(GL_SHADING_LANGUAGE_VERSION);
+    gl->vendor_str = (const char*)glGetString(GL_VENDOR);
+    if (!nk_x11_stricmpn(gl->vendor_str, "ATI", 4) ||
+        !nk_x11_stricmpn(gl->vendor_str, "AMD", 4))
+        gl->vendor = VENDOR_AMD;
+    else if (!nk_x11_stricmpn(gl->vendor_str, "NVIDIA", 6))
+        gl->vendor = VENDOR_NVIDIA;
+    else if (!nk_x11_stricmpn(gl->vendor_str, "Intel", 5))
+        gl->vendor = VENDOR_INTEL;
+    else gl->vendor = VENDOR_UNKNOWN;
+
+    /* Extensions */
+    gl->glsl_available = (gl->version >= 2.0f);
+    if (gl->glsl_available) {
+        /* GLSL core in OpenGL > 2 */
+        glCreateShader = GL_EXT(glCreateShader);
+        glShaderSource = GL_EXT(glShaderSource);
+        glCompileShader = GL_EXT(glCompileShader);
+        glGetShaderiv = GL_EXT(glGetShaderiv);
+        glGetShaderInfoLog = GL_EXT(glGetShaderInfoLog);
+        glDeleteShader = GL_EXT(glDeleteShader);
+        glCreateProgram = GL_EXT(glCreateProgram);
+        glAttachShader = GL_EXT(glAttachShader);
+        glDetachShader = GL_EXT(glDetachShader);
+        glLinkProgram = GL_EXT(glLinkProgram);
+        glUseProgram = GL_EXT(glUseProgram);
+        glGetProgramiv = GL_EXT(glGetProgramiv);
+        glGetProgramInfoLog = GL_EXT(glGetProgramInfoLog);
+        glDeleteProgram = GL_EXT(glDeleteProgram);
+        glGetUniformLocation = GL_EXT(glGetUniformLocation);
+        glGetAttribLocation = GL_EXT(glGetAttribLocation);
+        glUniform1i = GL_EXT(glUniform1i);
+        glUniform1f = GL_EXT(glUniform1f);
+        glUniformMatrix3fv = GL_EXT(glUniformMatrix3fv);
+        glUniformMatrix4fv = GL_EXT(glUniformMatrix4fv);
+    }
+    gl->vertex_buffer_obj_available = nk_x11_check_extension(gl, "GL_ARB_vertex_buffer_object");
+    if (gl->vertex_buffer_obj_available) {
+        /* GL_ARB_vertex_buffer_object */
+        glGenBuffers = GL_EXT(glGenBuffers);
+        glBindBuffer = GL_EXT(glBindBuffer);
+        glBufferData = GL_EXT(glBufferData);
+        glBufferSubData = GL_EXT(glBufferSubData);
+        glMapBuffer = GL_EXT(glMapBuffer);
+        glUnmapBuffer = GL_EXT(glUnmapBuffer);
+        glDeleteBuffers = GL_EXT(glDeleteBuffers);
+    }
+    gl->fragment_program_available = nk_x11_check_extension(gl, "GL_ARB_fragment_program");
+    if (gl->fragment_program_available) {
+        /* GL_ARB_vertex_program / GL_ARB_fragment_program  */
+        glVertexAttribPointer = GL_EXT(glVertexAttribPointer);
+        glEnableVertexAttribArray = GL_EXT(glEnableVertexAttribArray);
+        glDisableVertexAttribArray = GL_EXT(glDisableVertexAttribArray);
+    }
+    gl->vertex_array_obj_available = nk_x11_check_extension(gl, "GL_ARB_vertex_array_object");
+    if (gl->vertex_array_obj_available) {
+        /* GL_ARB_vertex_array_object */
+        glGenVertexArrays = GL_EXT(glGenVertexArrays);
+        glBindVertexArray = GL_EXT(glBindVertexArray);
+        glDeleteVertexArrays = GL_EXT(glDeleteVertexArrays);
+    }
+    gl->frame_buffer_object_available = nk_x11_check_extension(gl, "GL_ARB_framebuffer_object");
+    if (gl->frame_buffer_object_available) {
+        /* GL_ARB_framebuffer_object */
+        glGenerateMipmap = GL_EXT(glGenerateMipmap);
+    }
+    if (!gl->vertex_buffer_obj_available) {
+        fprintf(stdout, "[GL] Error: GL_ARB_vertex_buffer_object is not available!\n");
+        failed = TRUE;
+    }
+    if (!gl->fragment_program_available) {
+        fprintf(stdout, "[GL] Error: GL_ARB_fragment_program is not available!\n");
+        failed = TRUE;
+    }
+    if (!gl->vertex_array_obj_available) {
+        fprintf(stdout, "[GL] Error: GL_ARB_vertex_array_object is not available!\n");
+        failed = TRUE;
+    }
+    if (!gl->frame_buffer_object_available) {
+        fprintf(stdout, "[GL] Error: GL_ARB_framebuffer_object is not available!\n");
+        failed = TRUE;
+    }
+    return !failed;
+}
+#endif
+
+NK_API int
+nk_x11_device_create(void)
+{
+    GLint status;
+    static const GLchar *vertex_shader =
+        NK_SHADER_VERSION
+        "uniform mat4 ProjMtx;\n"
+        "in vec2 Position;\n"
+        "in vec2 TexCoord;\n"
+        "in vec4 Color;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main() {\n"
+        "   Frag_UV = TexCoord;\n"
+        "   Frag_Color = Color;\n"
+        "   gl_Position = ProjMtx * vec4(Position.xy, 0, 1);\n"
+        "}\n";
+    static const GLchar *fragment_shader =
+        NK_SHADER_VERSION
+        "precision mediump float;\n"
+        "uniform sampler2D Texture;\n"
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "out vec4 Out_Color;\n"
+        "void main(){\n"
+        "   Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    struct nk_x11_device *dev = &x11.ogl;
+#if NK_X11_LOAD_OPENGL_EXTENSIONS
+    if (!nk_load_opengl(&dev->info)) return 0;
+#endif
+    nk_buffer_init_default(&dev->cmds);
+
+    dev->prog = glCreateProgram();
+    dev->vert_shdr = glCreateShader(GL_VERTEX_SHADER);
+    dev->frag_shdr = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(dev->vert_shdr, 1, &vertex_shader, 0);
+    glShaderSource(dev->frag_shdr, 1, &fragment_shader, 0);
+    glCompileShader(dev->vert_shdr);
+    glCompileShader(dev->frag_shdr);
+    glGetShaderiv(dev->vert_shdr, GL_COMPILE_STATUS, &status);
+    assert(status == GL_TRUE);
+    glGetShaderiv(dev->frag_shdr, GL_COMPILE_STATUS, &status);
+    assert(status == GL_TRUE);
+    glAttachShader(dev->prog, dev->vert_shdr);
+    glAttachShader(dev->prog, dev->frag_shdr);
+    glLinkProgram(dev->prog);
+    glGetProgramiv(dev->prog, GL_LINK_STATUS, &status);
+    assert(status == GL_TRUE);
+
+    dev->uniform_tex = glGetUniformLocation(dev->prog, "Texture");
+    dev->uniform_proj = glGetUniformLocation(dev->prog, "ProjMtx");
+    dev->attrib_pos = glGetAttribLocation(dev->prog, "Position");
+    dev->attrib_uv = glGetAttribLocation(dev->prog, "TexCoord");
+    dev->attrib_col = glGetAttribLocation(dev->prog, "Color");
+
+    {
+        /* buffer setup */
+        GLsizei vs = sizeof(struct nk_draw_vertex);
+        size_t vp = offsetof(struct nk_draw_vertex, position);
+        size_t vt = offsetof(struct nk_draw_vertex, uv);
+        size_t vc = offsetof(struct nk_draw_vertex, col);
+
+        glGenBuffers(1, &dev->vbo);
+        glGenBuffers(1, &dev->ebo);
+        glGenVertexArrays(1, &dev->vao);
+
+        glBindVertexArray(dev->vao);
+        glBindBuffer(GL_ARRAY_BUFFER, dev->vbo);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo);
+
+        glEnableVertexAttribArray((GLuint)dev->attrib_pos);
+        glEnableVertexAttribArray((GLuint)dev->attrib_uv);
+        glEnableVertexAttribArray((GLuint)dev->attrib_col);
+
+        glVertexAttribPointer((GLuint)dev->attrib_pos, 2, GL_FLOAT, GL_FALSE, vs, (void*)vp);
+        glVertexAttribPointer((GLuint)dev->attrib_uv, 2, GL_FLOAT, GL_FALSE, vs, (void*)vt);
+        glVertexAttribPointer((GLuint)dev->attrib_col, 4, GL_UNSIGNED_BYTE, GL_TRUE, vs, (void*)vc);
+    }
+
+    glBindTexture(GL_TEXTURE_2D, 0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
+    return 1;
+}
+
+NK_INTERN void
+nk_x11_device_upload_atlas(const void *image, int width, int height)
+{
+    struct nk_x11_device *dev = &x11.ogl;
+    glGenTextures(1, &dev->font_tex);
+    glBindTexture(GL_TEXTURE_2D, dev->font_tex);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei)width, (GLsizei)height, 0,
+                GL_RGBA, GL_UNSIGNED_BYTE, image);
+}
+
+NK_API void
+nk_x11_device_destroy(void)
+{
+    struct nk_x11_device *dev = &x11.ogl;
+    glDetachShader(dev->prog, dev->vert_shdr);
+    glDetachShader(dev->prog, dev->frag_shdr);
+    glDeleteShader(dev->vert_shdr);
+    glDeleteShader(dev->frag_shdr);
+    glDeleteProgram(dev->prog);
+    glDeleteTextures(1, &dev->font_tex);
+    glDeleteBuffers(1, &dev->vbo);
+    glDeleteBuffers(1, &dev->ebo);
+    nk_buffer_free(&dev->cmds);
+}
+
+NK_API void
+nk_x11_render(enum nk_anti_aliasing AA, int max_vertex_buffer, int max_element_buffer)
+{
+    int width, height;
+    XWindowAttributes attr;
+    struct nk_x11_device *dev = &x11.ogl;
+    GLfloat ortho[4][4] = {
+        {2.0f, 0.0f, 0.0f, 0.0f},
+        {0.0f,-2.0f, 0.0f, 0.0f},
+        {0.0f, 0.0f,-1.0f, 0.0f},
+        {-1.0f,1.0f, 0.0f, 1.0f},
+    };
+    XGetWindowAttributes(x11.dpy, x11.win, &attr);
+    width = attr.width;
+    height = attr.height;
+
+    ortho[0][0] /= (GLfloat)width;
+    ortho[1][1] /= (GLfloat)height;
+
+    /* setup global state */
+    glEnable(GL_BLEND);
+    glBlendEquation(GL_FUNC_ADD);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glDisable(GL_CULL_FACE);
+    glDisable(GL_DEPTH_TEST);
+    glEnable(GL_SCISSOR_TEST);
+    glActiveTexture(GL_TEXTURE0);
+
+    /* setup program */
+    glUseProgram(dev->prog);
+    glUniform1i(dev->uniform_tex, 0);
+    glUniformMatrix4fv(dev->uniform_proj, 1, GL_FALSE, &ortho[0][0]);
+    glViewport(0,0,(GLsizei)width,(GLsizei)height);
+    {
+        /* convert from command queue into draw list and draw to screen */
+        const struct nk_draw_command *cmd;
+        void *vertices, *elements;
+        const nk_draw_index *offset = NULL;
+
+        /* allocate vertex and element buffer */
+        glBindVertexArray(dev->vao);
+        glBindBuffer(GL_ARRAY_BUFFER, dev->vbo);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo);
+
+        glBufferData(GL_ARRAY_BUFFER, max_vertex_buffer, NULL, GL_STREAM_DRAW);
+        glBufferData(GL_ELEMENT_ARRAY_BUFFER, max_element_buffer, NULL, GL_STREAM_DRAW);
+
+        /* load draw vertices & elements directly into vertex + element buffer */
+        vertices = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
+        elements = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY);
+        {
+            /* fill converting configuration */
+            struct nk_convert_config config;
+            memset(&config, 0, sizeof(config));
+            config.global_alpha = 1.0f;
+            config.shape_AA = AA;
+            config.line_AA = AA;
+            config.circle_segment_count = 22;
+            config.curve_segment_count = 22;
+            config.arc_segment_count = 22;
+            config.null = dev->null;
+
+            /* setup buffers to load vertices and elements */
+            {struct nk_buffer vbuf, ebuf;
+            nk_buffer_init_fixed(&vbuf, vertices, (size_t)max_vertex_buffer);
+            nk_buffer_init_fixed(&ebuf, elements, (size_t)max_element_buffer);
+            nk_convert(&x11.ctx, &dev->cmds, &vbuf, &ebuf, &config);}
+        }
+        glUnmapBuffer(GL_ARRAY_BUFFER);
+        glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
+
+        /* iterate over and execute each draw command */
+        nk_draw_foreach(cmd, &x11.ctx, &dev->cmds)
+        {
+            if (!cmd->elem_count) continue;
+            glBindTexture(GL_TEXTURE_2D, (GLuint)cmd->texture.id);
+            glScissor(
+                (GLint)(cmd->clip_rect.x),
+                (GLint)((height - (GLint)(cmd->clip_rect.y + cmd->clip_rect.h))),
+                (GLint)(cmd->clip_rect.w),
+                (GLint)(cmd->clip_rect.h));
+            glDrawElements(GL_TRIANGLES, (GLsizei)cmd->elem_count, GL_UNSIGNED_SHORT, offset);
+            offset += cmd->elem_count;
+        }
+        nk_clear(&x11.ctx);
+    }
+
+    /* default OpenGL state */
+    glUseProgram(0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
+    glDisable(GL_BLEND);
+    glDisable(GL_SCISSOR_TEST);
+}
+
+NK_API void
+nk_x11_font_stash_begin(struct nk_font_atlas **atlas)
+{
+    nk_font_atlas_init_default(&x11.atlas);
+    nk_font_atlas_begin(&x11.atlas);
+    *atlas = &x11.atlas;
+}
+
+NK_API void
+nk_x11_font_stash_end(void)
+{
+    const void *image; int w, h;
+    image = nk_font_atlas_bake(&x11.atlas, &w, &h, NK_FONT_ATLAS_RGBA32);
+    nk_x11_device_upload_atlas(image, w, h);
+    nk_font_atlas_end(&x11.atlas, nk_handle_id((int)x11.ogl.font_tex), &x11.ogl.null);
+    if (x11.atlas.default_font)
+        nk_style_set_font(&x11.ctx, &x11.atlas.default_font->handle);
+}
+
+NK_API void
+nk_x11_handle_event(XEvent *evt)
+{
+    struct nk_context *ctx = &x11.ctx;
+    if (evt->type == KeyPress || evt->type == KeyRelease)
+    {
+        /* Key handler */
+        int ret, down = (evt->type == KeyPress);
+        KeySym *code = XGetKeyboardMapping(x11.dpy, (KeyCode)evt->xkey.keycode, 1, &ret);
+        if (*code == XK_Shift_L || *code == XK_Shift_R) nk_input_key(ctx, NK_KEY_SHIFT, down);
+        else if (*code == XK_Delete)    nk_input_key(ctx, NK_KEY_DEL, down);
+        else if (*code == XK_Return)    nk_input_key(ctx, NK_KEY_ENTER, down);
+        else if (*code == XK_Tab)       nk_input_key(ctx, NK_KEY_TAB, down);
+        else if (*code == XK_Left)      nk_input_key(ctx, NK_KEY_LEFT, down);
+        else if (*code == XK_Right)     nk_input_key(ctx, NK_KEY_RIGHT, down);
+        else if (*code == XK_BackSpace) nk_input_key(ctx, NK_KEY_BACKSPACE, down);
+        else if (*code == XK_Home)  nk_input_key(ctx, NK_KEY_TEXT_START, down);
+        else if (*code == XK_End)  nk_input_key(ctx, NK_KEY_TEXT_END, down);
+        else if (*code == XK_space && !down) nk_input_char(ctx, ' ');
+        else {
+            if (*code == 'c' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_COPY, down);
+            else if (*code == 'v' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_PASTE, down);
+            else if (*code == 'x' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_CUT, down);
+            else if (*code == 'z' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_TEXT_UNDO, down);
+            else if (*code == 'r' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_TEXT_REDO, down);
+            else if (*code == XK_Left && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_TEXT_WORD_LEFT, down);
+            else if (*code == XK_Right && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_TEXT_WORD_RIGHT, down);
+            else if (*code == 'b' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_TEXT_LINE_START, down);
+            else if (*code == 'e' && (evt->xkey.state & ControlMask))
+                nk_input_key(ctx, NK_KEY_TEXT_LINE_END, down);
+            else if (!down) {
+                char buf[32];
+                KeySym keysym = 0;
+                if (XLookupString((XKeyEvent*)evt, buf, 32, &keysym, NULL) != NoSymbol)
+                    nk_input_glyph(ctx, buf);
+            }
+        }
+        XFree(code);
+    } else if (evt->type == ButtonPress || evt->type == ButtonRelease) {
+        /* Button handler */
+        int down = (evt->type == ButtonPress);
+        const int x = evt->xbutton.x, y = evt->xbutton.y;
+        if (evt->xbutton.button == Button1)
+            nk_input_button(ctx, NK_BUTTON_LEFT, x, y, down);
+        if (evt->xbutton.button == Button2)
+            nk_input_button(ctx, NK_BUTTON_MIDDLE, x, y, down);
+        else if (evt->xbutton.button == Button3)
+            nk_input_button(ctx, NK_BUTTON_RIGHT, x, y, down);
+        else if (evt->xbutton.button == Button4)
+            nk_input_scroll(ctx, 1.0f);
+        else if (evt->xbutton.button == Button5)
+            nk_input_scroll(ctx, -1.0f);
+
+    } else if (evt->type == MotionNotify) {
+        /* Mouse motion handler */
+        const int x = evt->xmotion.x, y = evt->xmotion.y;
+        nk_input_motion(ctx, x, y);
+    } else if (evt->type == KeymapNotify)
+        XRefreshKeyboardMapping(&evt->xmapping);
+}
+
+NK_API struct nk_context*
+nk_x11_init(Display *dpy, Window win)
+{
+    if (!setlocale(LC_ALL,"")) return 0;
+    if (!XSupportsLocale()) return 0;
+    if (!XSetLocaleModifiers("@im=none")) return 0;
+    if (!nk_x11_device_create()) return 0;
+    x11.dpy = dpy;
+    x11.win = win;
+    nk_init_default(&x11.ctx, 0);
+    return &x11.ctx;
+}
+
+NK_API void
+nk_x11_shutdown(void)
+{
+    nk_font_atlas_clear(&x11.atlas);
+    nk_free(&x11.ctx);
+    nk_x11_device_destroy();
+    memset(&x11, 0, sizeof(x11));
+}
+

demo/x11_opengl3/nuklear_x11.h

@@ -0,0 +1,25 @@
+#ifndef NK_X11_OPENGL_H_
+#define NK_X11_OPENGL_H_
+
+#include "../../nuklear.h"
+
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xresource.h>
+
+/* Define this to 0 if you already load all required OpenGL extensions yourself
+ * otherwise define to 1 to let nuklear load its required extensions. */
+#define NK_X11_LOAD_OPENGL_EXTENSIONS 1
+
+NK_API struct nk_context *nk_x11_init(Display *dpy, Window win);
+NK_API void nk_x11_font_stash_begin(struct nk_font_atlas **atlas);
+NK_API void nk_x11_font_stash_end(void);
+NK_API void nk_x11_handle_event(XEvent *evt);
+NK_API void nk_x11_render(enum nk_anti_aliasing, int max_vertex_buffer, int max_element_buffer);
+NK_API void nk_x11_shutdown(void);
+
+NK_API int nk_x11_device_create(void);
+NK_API void nk_x11_device_destroy(void);
+
+
+#endif