Nuklear/demo/sdl_opengles2/nuklear_sdl_gles2.h
2021-06-18 16:19:49 +02:00

445 lines
16 KiB
C

/*
* 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 <SDL2/SDL.h>
#include <SDL2/SDL_opengles2.h>
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;
#define NK_SHADER_VERSION "#version 100\n"
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
"precision mediump float;\n"
"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}
};
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);
nk_buffer_clear(&dev->cmds);
}
glUseProgram(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
glDisable(GL_BLEND);
glDisable(GL_SCISSOR_TEST);
}
static void
nk_sdl_clipboard_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_clipboard_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_clipboard_copy;
sdl.ctx.clip.paste = nk_sdl_clipboard_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