Nuklear/demo/sdl_opengl2/nuklear_sdl_gl2.h
paccer 56ab9d96ea Added comment to nk_sdl_handle_grab in SDL demos
Explains call order of SDL_SetRelativeMouseMode and SDL_SetWindowGrab
2024-02-23 20:39:08 +01:00

353 lines
13 KiB
C

/*
* Nuklear - 1.32.0 - public domain
* no warrenty implied; use at your own risk.
* authored from 2015-2017 by Micha Mettke
*/
/*
* ==============================================================
*
* API
*
* ===============================================================
*/
#ifndef NK_SDL_GL2_H_
#define NK_SDL_GL2_H_
#include <SDL2/SDL.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);
NK_API void nk_sdl_shutdown(void);
#endif
/*
* ==============================================================
*
* IMPLEMENTATION
*
* ===============================================================
*/
#ifdef NK_SDL_GL2_IMPLEMENTATION
#include <string.h>
#include <stdlib.h>
struct nk_sdl_device {
struct nk_buffer cmds;
struct nk_draw_null_texture tex_null;
GLuint font_tex;
};
struct nk_sdl_vertex {
float position[2];
float 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;
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_render(enum nk_anti_aliasing AA)
{
/* setup global state */
struct nk_sdl_device *dev = &sdl.ogl;
int width, height;
int display_width, display_height;
struct nk_vec2 scale;
SDL_GetWindowSize(sdl.win, &width, &height);
SDL_GL_GetDrawableSize(sdl.win, &display_width, &display_height);
scale.x = (float)display_width/(float)width;
scale.y = (float)display_height/(float)height;
glPushAttrib(GL_ENABLE_BIT|GL_COLOR_BUFFER_BIT|GL_TRANSFORM_BIT);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glEnable(GL_SCISSOR_TEST);
glEnable(GL_BLEND);
glEnable(GL_TEXTURE_2D);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
/* setup viewport/project */
glViewport(0,0,(GLsizei)display_width,(GLsizei)display_height);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0f, width, height, 0.0f, -1.0f, 1.0f);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
{
GLsizei vs = sizeof(struct nk_sdl_vertex);
size_t vp = offsetof(struct nk_sdl_vertex, position);
size_t vt = offsetof(struct nk_sdl_vertex, uv);
size_t vc = offsetof(struct nk_sdl_vertex, col);
/* convert from command queue into draw list and draw to screen */
const struct nk_draw_command *cmd;
const nk_draw_index *offset = NULL;
struct nk_buffer vbuf, ebuf;
/* fill converting 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.tex_null = dev->tex_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;
/* convert shapes into vertexes */
nk_buffer_init_default(&vbuf);
nk_buffer_init_default(&ebuf);
nk_convert(&sdl.ctx, &dev->cmds, &vbuf, &ebuf, &config);
/* setup vertex buffer pointer */
{const void *vertices = nk_buffer_memory_const(&vbuf);
glVertexPointer(2, GL_FLOAT, vs, (const void*)((const nk_byte*)vertices + vp));
glTexCoordPointer(2, GL_FLOAT, vs, (const void*)((const nk_byte*)vertices + vt));
glColorPointer(4, GL_UNSIGNED_BYTE, vs, (const void*)((const nk_byte*)vertices + vc));}
/* iterate over and execute each draw command */
offset = (const nk_draw_index*)nk_buffer_memory_const(&ebuf);
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);
nk_buffer_free(&vbuf);
nk_buffer_free(&ebuf);
}
/* default OpenGL state */
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glDisable(GL_SCISSOR_TEST);
glDisable(GL_BLEND);
glDisable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glPopAttrib();
}
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_buffer_init_default(&sdl.ogl.cmds);
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.tex_null);
if (sdl.atlas.default_font)
nk_style_set_font(&sdl.ctx, &sdl.atlas.default_font->handle);
}
NK_API void
nk_sdl_handle_grab(void)
{
struct nk_context *ctx = &sdl.ctx;
if (ctx->input.mouse.grab) {
SDL_SetRelativeMouseMode(SDL_TRUE);
} else if (ctx->input.mouse.ungrab) {
/* better support for older SDL by setting mode first; causes an extra mouse motion event */
SDL_SetRelativeMouseMode(SDL_FALSE);
SDL_WarpMouseInWindow(sdl.win, (int)ctx->input.mouse.prev.x, (int)ctx->input.mouse.prev.y);
} else if (ctx->input.mouse.grabbed) {
ctx->input.mouse.pos.x = ctx->input.mouse.prev.x;
ctx->input.mouse.pos.y = ctx->input.mouse.prev.y;
}
}
NK_API int
nk_sdl_handle_event(SDL_Event *evt)
{
struct nk_context *ctx = &sdl.ctx;
switch(evt->type)
{
case SDL_KEYUP: /* KEYUP & KEYDOWN share same routine */
case SDL_KEYDOWN:
{
int down = evt->type == SDL_KEYDOWN;
const Uint8* state = SDL_GetKeyboardState(0);
switch(evt->key.keysym.sym)
{
case SDLK_RSHIFT: /* RSHIFT & LSHIFT share same routine */
case SDLK_LSHIFT: nk_input_key(ctx, NK_KEY_SHIFT, down); break;
case SDLK_DELETE: nk_input_key(ctx, NK_KEY_DEL, down); break;
case SDLK_RETURN: nk_input_key(ctx, NK_KEY_ENTER, down); break;
case SDLK_TAB: nk_input_key(ctx, NK_KEY_TAB, down); break;
case SDLK_BACKSPACE: nk_input_key(ctx, NK_KEY_BACKSPACE, down); break;
case SDLK_HOME: nk_input_key(ctx, NK_KEY_TEXT_START, down);
nk_input_key(ctx, NK_KEY_SCROLL_START, down); break;
case SDLK_END: nk_input_key(ctx, NK_KEY_TEXT_END, down);
nk_input_key(ctx, NK_KEY_SCROLL_END, down); break;
case SDLK_PAGEDOWN: nk_input_key(ctx, NK_KEY_SCROLL_DOWN, down); break;
case SDLK_PAGEUP: nk_input_key(ctx, NK_KEY_SCROLL_UP, down); break;
case SDLK_z: nk_input_key(ctx, NK_KEY_TEXT_UNDO, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_r: nk_input_key(ctx, NK_KEY_TEXT_REDO, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_c: nk_input_key(ctx, NK_KEY_COPY, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_v: nk_input_key(ctx, NK_KEY_PASTE, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_x: nk_input_key(ctx, NK_KEY_CUT, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_b: nk_input_key(ctx, NK_KEY_TEXT_LINE_START, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_e: nk_input_key(ctx, NK_KEY_TEXT_LINE_END, down && state[SDL_SCANCODE_LCTRL]); break;
case SDLK_UP: nk_input_key(ctx, NK_KEY_UP, down); break;
case SDLK_DOWN: nk_input_key(ctx, NK_KEY_DOWN, down); break;
case 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);
break;
case 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);
break;
}
}
return 1;
case SDL_MOUSEBUTTONUP: /* MOUSEBUTTONUP & MOUSEBUTTONDOWN share same routine */
case SDL_MOUSEBUTTONDOWN:
{
int down = evt->type == SDL_MOUSEBUTTONDOWN;
const int x = evt->button.x, y = evt->button.y;
switch(evt->button.button)
{
case 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); break;
case SDL_BUTTON_MIDDLE: nk_input_button(ctx, NK_BUTTON_MIDDLE, x, y, down); break;
case SDL_BUTTON_RIGHT: nk_input_button(ctx, NK_BUTTON_RIGHT, x, y, down); break;
}
}
return 1;
case SDL_MOUSEMOTION:
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;
case SDL_TEXTINPUT:
{
nk_glyph glyph;
memcpy(glyph, evt->text.text, NK_UTF_SIZE);
nk_input_glyph(ctx, glyph);
}
return 1;
case SDL_MOUSEWHEEL:
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)
{
struct nk_sdl_device *dev = &sdl.ogl;
nk_font_atlas_clear(&sdl.atlas);
nk_free(&sdl.ctx);
glDeleteTextures(1, &dev->font_tex);
nk_buffer_free(&dev->cmds);
memset(&sdl, 0, sizeof(sdl));
}
#endif