lite-xl/src/api/renderer.c

#include "api.h"
#include "renderer.h"
#include "rencache.h"

static int f_font_load(lua_State *L) {
  const char *filename  = luaL_checkstring(L, 1);
  float size = luaL_checknumber(L, 2);
  unsigned int font_hinting = FONT_HINTING_SLIGHT, font_style = 0;
  bool subpixel = true;
  if (lua_gettop(L) > 2 && lua_istable(L, 3)) {
    lua_getfield(L, 3, "antialiasing");
    if (lua_isstring(L, -1)) {
      const char *antialiasing = lua_tostring(L, -1);
      if (antialiasing) {
        if (strcmp(antialiasing, "grayscale") == 0) {
          subpixel = false;
        } else if (strcmp(antialiasing, "subpixel") == 0) {
          subpixel = true;
        } else {
          return luaL_error(L, "error in renderer.font.load, unknown antialiasing option: \"%s\"", antialiasing);
        }
      }
    }
    lua_getfield(L, 3, "hinting");
    if (lua_isstring(L, -1)) {
      const char *hinting = lua_tostring(L, -1);
      if (hinting) {
        if (strcmp(hinting, "slight") == 0) {
          font_hinting = FONT_HINTING_SLIGHT;
        } else if (strcmp(hinting, "none") == 0) {
          font_hinting = FONT_HINTING_NONE;
        } else if (strcmp(hinting, "full") == 0) {
          font_hinting = FONT_HINTING_FULL;
        } else {
          return luaL_error(L, "error in renderer.font.load, unknown hinting option: \"%s\"", hinting);
        }
      }
    }
    lua_getfield(L, 3, "italic");
    if (lua_toboolean(L, -1))
      font_style |= FONT_STYLE_ITALIC;
    lua_getfield(L, 3, "bold");
    if (lua_toboolean(L, -1))
      font_style |= FONT_STYLE_BOLD;
    lua_getfield(L, 3, "underline");
    if (lua_toboolean(L, -1))
      font_style |= FONT_STYLE_UNDERLINE;
    lua_pop(L, 5);
  }
  RenFont** font = lua_newuserdata(L, sizeof(RenFont*));
  *font = ren_font_load(filename, size, subpixel, font_hinting, font_style);
  if (!*font)
    return luaL_error(L, "failed to load font");
  luaL_setmetatable(L, API_TYPE_FONT);
  return 1;
}

static bool font_retrieve(lua_State* L, RenFont** fonts, int idx) {
  memset(fonts, 0, sizeof(RenFont*)*FONT_FALLBACK_MAX);
  if (lua_type(L, 1) != LUA_TTABLE) {
    fonts[0] = *(RenFont**)luaL_checkudata(L, idx, API_TYPE_FONT);
    return false;
  }
  int i = 0;
  do {
    lua_rawgeti(L, idx, i+1);
    fonts[i] = !lua_isnil(L, -1) ? *(RenFont**)luaL_checkudata(L, -1, API_TYPE_FONT) : NULL;
    lua_pop(L, 1);
  } while (fonts[i] && i++ < FONT_FALLBACK_MAX);
  return true;
}

static int f_font_copy(lua_State *L) {
  RenFont* fonts[FONT_FALLBACK_MAX];
  bool table = font_retrieve(L, fonts, 1);
  float size = lua_gettop(L) >= 2 ? luaL_checknumber(L, 2) : ren_font_group_get_height(fonts);
  if (table) {
    lua_newtable(L);
    luaL_setmetatable(L, API_TYPE_FONT);
  }
  for (int i = 0; i < FONT_FALLBACK_MAX && fonts[i]; ++i) {
    RenFont** font = lua_newuserdata(L, sizeof(RenFont*));
    *font = ren_font_copy(fonts[i], size);
    if (!*font)
      return luaL_error(L, "failed to copy font");
    luaL_setmetatable(L, API_TYPE_FONT);
    if (table)
      lua_rawseti(L, -2, i+1);
  }
  return 1;
}

static int f_font_group(lua_State* L) { 
  luaL_checktype(L, 1, LUA_TTABLE);
  luaL_setmetatable(L, API_TYPE_FONT);
  return 1;
}

static int f_font_set_tab_size(lua_State *L) {
  RenFont* fonts[FONT_FALLBACK_MAX]; font_retrieve(L, fonts, 1);
  int n = luaL_checknumber(L, 2);
  ren_font_group_set_tab_size(fonts, n);
  return 0;
}

static int f_font_gc(lua_State *L) {
  RenFont** self = luaL_checkudata(L, 1, API_TYPE_FONT);
  ren_font_free(*self);
  return 0;
}


static int f_font_get_width(lua_State *L) {
  RenFont* fonts[FONT_FALLBACK_MAX]; font_retrieve(L, fonts, 1);
  lua_pushnumber(L, ren_font_group_get_width(fonts, luaL_checkstring(L, 2)));
  return 1;
}

static int f_font_get_height(lua_State *L) {
  RenFont* fonts[FONT_FALLBACK_MAX]; font_retrieve(L, fonts, 1);
  lua_pushnumber(L, ren_font_group_get_height(fonts));
  return 1;
}

static int f_font_get_size(lua_State *L) {
  RenFont* fonts[FONT_FALLBACK_MAX]; font_retrieve(L, fonts, 1);
  lua_pushnumber(L, ren_font_group_get_size(fonts));
  return 1;
}

static RenColor checkcolor(lua_State *L, int idx, int def) {
  RenColor color;
  if (lua_isnoneornil(L, idx)) {
    return (RenColor) { def, def, def, 255 };
  }
  lua_rawgeti(L, idx, 1);
  lua_rawgeti(L, idx, 2);
  lua_rawgeti(L, idx, 3);
  lua_rawgeti(L, idx, 4);
  color.r = luaL_checknumber(L, -4);
  color.g = luaL_checknumber(L, -3);
  color.b = luaL_checknumber(L, -2);
  color.a = luaL_optnumber(L, -1, 255);
  lua_pop(L, 4);
  return color;
}


static int f_show_debug(lua_State *L) {
  luaL_checkany(L, 1);
  rencache_show_debug(lua_toboolean(L, 1));
  return 0;
}


static int f_get_size(lua_State *L) {
  int w, h;
  ren_get_size(&w, &h);
  lua_pushnumber(L, w);
  lua_pushnumber(L, h);
  return 2;
}


static int f_begin_frame(lua_State *L) {
  rencache_begin_frame(L);
  return 0;
}


static int f_end_frame(lua_State *L) {
  rencache_end_frame(L);
  return 0;
}


static int f_set_clip_rect(lua_State *L) {
  RenRect rect;
  rect.x = luaL_checknumber(L, 1);
  rect.y = luaL_checknumber(L, 2);
  rect.width = luaL_checknumber(L, 3);
  rect.height = luaL_checknumber(L, 4);
  rencache_set_clip_rect(rect);
  return 0;
}


static int f_draw_rect(lua_State *L) {
  RenRect rect;
  rect.x = luaL_checknumber(L, 1);
  rect.y = luaL_checknumber(L, 2);
  rect.width = luaL_checknumber(L, 3);
  rect.height = luaL_checknumber(L, 4);
  RenColor color = checkcolor(L, 5, 255);
  rencache_draw_rect(rect, color);
  return 0;
}

static int f_draw_text(lua_State *L) {
  RenFont* fonts[FONT_FALLBACK_MAX];
  font_retrieve(L, fonts, 1);
  const char *text = luaL_checkstring(L, 2);
  float x = luaL_checknumber(L, 3);
  int y = luaL_checknumber(L, 4);
  RenColor color = checkcolor(L, 5, 255);
  x = rencache_draw_text(L, fonts, text, x, y, color);
  lua_pushnumber(L, x);
  return 1;
}

static const luaL_Reg lib[] = {
  { "show_debug",         f_show_debug         },
  { "get_size",           f_get_size           },
  { "begin_frame",        f_begin_frame        },
  { "end_frame",          f_end_frame          },
  { "set_clip_rect",      f_set_clip_rect      },
  { "draw_rect",          f_draw_rect          },
  { "draw_text",          f_draw_text          },
  { NULL,                 NULL                 }
};

static const luaL_Reg fontLib[] = {
  { "__gc",               f_font_gc                 },
  { "load",               f_font_load               },
  { "copy",               f_font_copy               },
  { "group",              f_font_group              },
  { "set_tab_size",       f_font_set_tab_size       },
  { "get_width",          f_font_get_width          },
  { "get_height",         f_font_get_height         },
  { "get_size",           f_font_get_size           },
  { NULL, NULL }
};

int luaopen_renderer(lua_State *L) {
  luaL_newlib(L, lib);
  luaL_newmetatable(L, API_TYPE_FONT);
  luaL_setfuncs(L, fontLib, 0);
  lua_pushvalue(L, -1);
  lua_setfield(L, -2, "__index");
  lua_setfield(L, -2, "font");
  return 1;
}