--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nuklear_ui/nuklear_sdl_gles2.h	Sat Jan 05 00:58:08 2019 -0800
@@ -0,0 +1,454 @@
+/*
+ * Nuklear - 1.40.8 - public domain
+ * no warrenty implied; use at your own risk.
+ * authored from 2015-2017 by Micha Mettke
+ * emscripten from 2016 by Chris Willcocks
+ * OpenGL ES 2.0 from 2017 by Dmitry Hrabrov a.k.a. DeXPeriX
+ */
+/*
+ * ==============================================================
+ *
+ *                              API
+ *
+ * ===============================================================
+ */
+#ifndef NK_SDL_GLES2_H_
+#define NK_SDL_GLES2_H_
+
+#include <SDL.h>
+#ifndef DISABLE_OPENGL
+#ifdef USE_GLES
+#include <SDL_opengles2.h>
+#else
+#include <GL/glew.h>
+#endif
+#endif
+
+
+NK_API struct nk_context*   nk_sdl_init(SDL_Window *win);
+NK_API void                 nk_sdl_font_stash_begin(struct nk_font_atlas **atlas);
+NK_API void                 nk_sdl_font_stash_end(void);
+NK_API int                  nk_sdl_handle_event(SDL_Event *evt);
+NK_API void                 nk_sdl_render(enum nk_anti_aliasing , int max_vertex_buffer, int max_element_buffer);
+NK_API void                 nk_sdl_shutdown(void);
+NK_API void                 nk_sdl_device_destroy(void);
+NK_API void                 nk_sdl_device_create(void);
+
+#endif
+
+/*
+ * ==============================================================
+ *
+ *                          IMPLEMENTATION
+ *
+ * ===============================================================
+ */
+#ifdef NK_SDL_GLES2_IMPLEMENTATION
+
+#include <string.h>
+
+struct nk_sdl_device {
+    struct nk_buffer cmds;
+    struct nk_draw_null_texture null;
+    GLuint vbo, 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;
+    GLsizei vs;
+    size_t vp, vt, vc;
+};
+
+struct nk_sdl_vertex {
+    GLfloat position[2];
+    GLfloat uv[2];
+    nk_byte col[4];
+};
+
+static struct nk_sdl {
+    SDL_Window *win;
+    struct nk_sdl_device ogl;
+    struct nk_context ctx;
+    struct nk_font_atlas atlas;
+} sdl;
+
+#ifdef USE_GLES
+#define NK_SHADER_VERSION "#version 100\n"
+#define DECLARE_PRECISION "precision mediump float;\n"
+#else
+#define NK_SHADER_VERSION "#version 110\n"
+#define DECLARE_PRECISION
+#endif
+
+
+NK_API void
+nk_sdl_device_create(void)
+{
+    GLint status;
+    static const GLchar *vertex_shader =
+        NK_SHADER_VERSION
+        "uniform mat4 ProjMtx;\n"
+        "attribute vec2 Position;\n"
+        "attribute vec2 TexCoord;\n"
+        "attribute vec4 Color;\n"
+        "varying vec2 Frag_UV;\n"
+        "varying 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
+        DECLARE_PRECISION
+        "uniform sampler2D Texture;\n"
+        "varying vec2 Frag_UV;\n"
+        "varying vec4 Frag_Color;\n"
+        "void main(){\n"
+        "   gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV);\n"
+        "}\n";
+
+    struct nk_sdl_device *dev = &sdl.ogl;
+    
+    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");
+    {
+        dev->vs = sizeof(struct nk_sdl_vertex);
+        dev->vp = offsetof(struct nk_sdl_vertex, position);
+        dev->vt = offsetof(struct nk_sdl_vertex, uv);
+        dev->vc = offsetof(struct nk_sdl_vertex, col);
+        
+        /* Allocate buffers */
+        glGenBuffers(1, &dev->vbo);
+        glGenBuffers(1, &dev->ebo);
+    }
+    glBindTexture(GL_TEXTURE_2D, 0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+}
+
+NK_INTERN void
+nk_sdl_device_upload_atlas(const void *image, int width, int height)
+{
+    struct nk_sdl_device *dev = &sdl.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_sdl_device_destroy(void)
+{
+    struct nk_sdl_device *dev = &sdl.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_sdl_render(enum nk_anti_aliasing AA, int max_vertex_buffer, int max_element_buffer)
+{
+    struct nk_sdl_device *dev = &sdl.ogl;
+    int width, height;
+    int display_width, display_height;
+    struct nk_vec2 scale;
+    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},
+    };
+    SDL_GetWindowSize(sdl.win, &width, &height);
+    SDL_GL_GetDrawableSize(sdl.win, &display_width, &display_height);
+    ortho[0][0] /= (GLfloat)width;
+    ortho[1][1] /= (GLfloat)height;
+
+    scale.x = (float)display_width/(float)width;
+    scale.y = (float)display_height/(float)height;
+
+    /* setup global state */
+    glViewport(0,0,display_width,display_height);
+    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]);
+    {
+        /* 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;
+
+        /* Bind buffers */
+        glBindBuffer(GL_ARRAY_BUFFER, dev->vbo);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo);
+        
+        {
+            /* buffer setup */
+            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, dev->vs, (void*)dev->vp);
+            glVertexAttribPointer((GLuint)dev->attrib_uv, 2, GL_FLOAT, GL_FALSE, dev->vs, (void*)dev->vt);
+            glVertexAttribPointer((GLuint)dev->attrib_col, 4, GL_UNSIGNED_BYTE, GL_TRUE, dev->vs, (void*)dev->vc);
+        }
+
+        glBufferData(GL_ARRAY_BUFFER, max_vertex_buffer, NULL, GL_STREAM_DRAW);
+        glBufferData(GL_ELEMENT_ARRAY_BUFFER, max_element_buffer, NULL, GL_STREAM_DRAW);
+
+        /* load vertices/elements directly into vertex/element buffer */
+        vertices = malloc((size_t)max_vertex_buffer);
+        elements = malloc((size_t)max_element_buffer);
+        {
+            /* fill convert configuration */
+            struct nk_convert_config config;
+            static const struct nk_draw_vertex_layout_element vertex_layout[] = {
+                {NK_VERTEX_POSITION, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sdl_vertex, position)},
+                {NK_VERTEX_TEXCOORD, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_sdl_vertex, uv)},
+                {NK_VERTEX_COLOR, NK_FORMAT_R8G8B8A8, NK_OFFSETOF(struct nk_sdl_vertex, col)},
+                {NK_VERTEX_LAYOUT_END}
+            };
+            NK_MEMSET(&config, 0, sizeof(config));
+            config.vertex_layout = vertex_layout;
+            config.vertex_size = sizeof(struct nk_sdl_vertex);
+            config.vertex_alignment = NK_ALIGNOF(struct nk_sdl_vertex);
+            config.null = dev->null;
+            config.circle_segment_count = 22;
+            config.curve_segment_count = 22;
+            config.arc_segment_count = 22;
+            config.global_alpha = 1.0f;
+            config.shape_AA = AA;
+            config.line_AA = AA;
+
+            /* setup buffers to load vertices and elements */
+            {struct nk_buffer vbuf, ebuf;
+            nk_buffer_init_fixed(&vbuf, vertices, (nk_size)max_vertex_buffer);
+            nk_buffer_init_fixed(&ebuf, elements, (nk_size)max_element_buffer);
+            nk_convert(&sdl.ctx, &dev->cmds, &vbuf, &ebuf, &config);}
+        }
+        glBufferSubData(GL_ARRAY_BUFFER, 0, (size_t)max_vertex_buffer, vertices);
+        glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, (size_t)max_element_buffer, elements);
+        free(vertices);
+        free(elements);
+
+        /* iterate over and execute each draw command */
+        nk_draw_foreach(cmd, &sdl.ctx, &dev->cmds) {
+            if (!cmd->elem_count) continue;
+            glBindTexture(GL_TEXTURE_2D, (GLuint)cmd->texture.id);
+            glScissor((GLint)(cmd->clip_rect.x * scale.x),
+                (GLint)((height - (GLint)(cmd->clip_rect.y + cmd->clip_rect.h)) * scale.y),
+                (GLint)(cmd->clip_rect.w * scale.x),
+                (GLint)(cmd->clip_rect.h * scale.y));
+            glDrawElements(GL_TRIANGLES, (GLsizei)cmd->elem_count, GL_UNSIGNED_SHORT, offset);
+            offset += cmd->elem_count;
+        }
+        nk_clear(&sdl.ctx);
+    }
+
+    glUseProgram(0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+    glDisable(GL_BLEND);
+    glDisable(GL_SCISSOR_TEST);
+}
+
+static void
+nk_sdl_clipbard_paste(nk_handle usr, struct nk_text_edit *edit)
+{
+    const char *text = SDL_GetClipboardText();
+    if (text) nk_textedit_paste(edit, text, nk_strlen(text));
+    (void)usr;
+}
+
+static void
+nk_sdl_clipbard_copy(nk_handle usr, const char *text, int len)
+{
+    char *str = 0;
+    (void)usr;
+    if (!len) return;
+    str = (char*)malloc((size_t)len+1);
+    if (!str) return;
+    memcpy(str, text, (size_t)len);
+    str[len] = '\0';
+    SDL_SetClipboardText(str);
+    free(str);
+}
+
+NK_API struct nk_context*
+nk_sdl_init(SDL_Window *win)
+{
+    sdl.win = win;
+    nk_init_default(&sdl.ctx, 0);
+    sdl.ctx.clip.copy = nk_sdl_clipbard_copy;
+    sdl.ctx.clip.paste = nk_sdl_clipbard_paste;
+    sdl.ctx.clip.userdata = nk_handle_ptr(0);
+    nk_sdl_device_create();
+    return &sdl.ctx;
+}
+
+NK_API void
+nk_sdl_font_stash_begin(struct nk_font_atlas **atlas)
+{
+    nk_font_atlas_init_default(&sdl.atlas);
+    nk_font_atlas_begin(&sdl.atlas);
+    *atlas = &sdl.atlas;
+}
+
+NK_API void
+nk_sdl_font_stash_end(void)
+{
+    const void *image; int w, h;
+    image = nk_font_atlas_bake(&sdl.atlas, &w, &h, NK_FONT_ATLAS_RGBA32);
+    nk_sdl_device_upload_atlas(image, w, h);
+    nk_font_atlas_end(&sdl.atlas, nk_handle_id((int)sdl.ogl.font_tex), &sdl.ogl.null);
+    if (sdl.atlas.default_font)
+        nk_style_set_font(&sdl.ctx, &sdl.atlas.default_font->handle);
+
+}
+
+NK_API int
+nk_sdl_handle_event(SDL_Event *evt)
+{
+    struct nk_context *ctx = &sdl.ctx;
+    if (evt->type == SDL_KEYUP || evt->type == SDL_KEYDOWN) {
+        /* key events */
+        int down = evt->type == SDL_KEYDOWN;
+        const Uint8* state = SDL_GetKeyboardState(0);
+        SDL_Keycode sym = evt->key.keysym.sym;
+        if (sym == SDLK_RSHIFT || sym == SDLK_LSHIFT)
+            nk_input_key(ctx, NK_KEY_SHIFT, down);
+        else if (sym == SDLK_DELETE)
+            nk_input_key(ctx, NK_KEY_DEL, down);
+        else if (sym == SDLK_RETURN)
+            nk_input_key(ctx, NK_KEY_ENTER, down);
+        else if (sym == SDLK_TAB)
+            nk_input_key(ctx, NK_KEY_TAB, down);
+        else if (sym == SDLK_BACKSPACE)
+            nk_input_key(ctx, NK_KEY_BACKSPACE, down);
+        else if (sym == SDLK_HOME) {
+            nk_input_key(ctx, NK_KEY_TEXT_START, down);
+            nk_input_key(ctx, NK_KEY_SCROLL_START, down);
+        } else if (sym == SDLK_END) {
+            nk_input_key(ctx, NK_KEY_TEXT_END, down);
+            nk_input_key(ctx, NK_KEY_SCROLL_END, down);
+        } else if (sym == SDLK_PAGEDOWN) {
+            nk_input_key(ctx, NK_KEY_SCROLL_DOWN, down);
+        } else if (sym == SDLK_PAGEUP) {
+            nk_input_key(ctx, NK_KEY_SCROLL_UP, down);
+        } else if (sym == SDLK_z)
+            nk_input_key(ctx, NK_KEY_TEXT_UNDO, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_r)
+            nk_input_key(ctx, NK_KEY_TEXT_REDO, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_c)
+            nk_input_key(ctx, NK_KEY_COPY, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_v)
+            nk_input_key(ctx, NK_KEY_PASTE, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_x)
+            nk_input_key(ctx, NK_KEY_CUT, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_b)
+            nk_input_key(ctx, NK_KEY_TEXT_LINE_START, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_e)
+            nk_input_key(ctx, NK_KEY_TEXT_LINE_END, down && state[SDL_SCANCODE_LCTRL]);
+        else if (sym == SDLK_UP)
+            nk_input_key(ctx, NK_KEY_UP, down);
+        else if (sym == SDLK_DOWN)
+            nk_input_key(ctx, NK_KEY_DOWN, down);
+        else if (sym == SDLK_LEFT) {
+            if (state[SDL_SCANCODE_LCTRL])
+                nk_input_key(ctx, NK_KEY_TEXT_WORD_LEFT, down);
+            else nk_input_key(ctx, NK_KEY_LEFT, down);
+        } else if (sym == SDLK_RIGHT) {
+            if (state[SDL_SCANCODE_LCTRL])
+                nk_input_key(ctx, NK_KEY_TEXT_WORD_RIGHT, down);
+            else nk_input_key(ctx, NK_KEY_RIGHT, down);
+        } else return 0;
+        return 1;
+    } else if (evt->type == SDL_MOUSEBUTTONDOWN || evt->type == SDL_MOUSEBUTTONUP) {
+        /* mouse button */
+        int down = evt->type == SDL_MOUSEBUTTONDOWN;
+        const int x = evt->button.x, y = evt->button.y;
+        if (evt->button.button == SDL_BUTTON_LEFT) {
+            if (evt->button.clicks > 1)
+                nk_input_button(ctx, NK_BUTTON_DOUBLE, x, y, down);
+            nk_input_button(ctx, NK_BUTTON_LEFT, x, y, down);
+        } else if (evt->button.button == SDL_BUTTON_MIDDLE)
+            nk_input_button(ctx, NK_BUTTON_MIDDLE, x, y, down);
+        else if (evt->button.button == SDL_BUTTON_RIGHT)
+            nk_input_button(ctx, NK_BUTTON_RIGHT, x, y, down);
+        return 1;
+    } else if (evt->type == SDL_MOUSEMOTION) {
+        /* mouse motion */
+        if (ctx->input.mouse.grabbed) {
+            int x = (int)ctx->input.mouse.prev.x, y = (int)ctx->input.mouse.prev.y;
+            nk_input_motion(ctx, x + evt->motion.xrel, y + evt->motion.yrel);
+        } else nk_input_motion(ctx, evt->motion.x, evt->motion.y);
+        return 1;
+    } else if (evt->type == SDL_TEXTINPUT) {
+        /* text input */
+        nk_glyph glyph;
+        memcpy(glyph, evt->text.text, NK_UTF_SIZE);
+        nk_input_glyph(ctx, glyph);
+        return 1;
+    } else if (evt->type == SDL_MOUSEWHEEL) {
+        /* mouse wheel */
+        nk_input_scroll(ctx,nk_vec2((float)evt->wheel.x,(float)evt->wheel.y));
+        return 1;
+    }
+    return 0;
+}
+
+NK_API
+void nk_sdl_shutdown(void)
+{
+    nk_font_atlas_clear(&sdl.atlas);
+    nk_free(&sdl.ctx);
+    nk_sdl_device_destroy();
+    memset(&sdl, 0, sizeof(sdl));
+}
+
+#endif