SDL_TTF 2.20.0(启用 Harfbuzz)引入了 TTF_SetFontDirection()
和 TTF_SetFontScriptName()
“以使用 HarfBuzz 对字体进行额外控制”。
我正在尝试渲染一些阿拉伯语文本,并且我已将字体方向设置为 RTL 并将脚本名称设置为 "arSA\0"
,但字形没有正确连接。
TTF_SetFontDirection(ttf_font, TTF_DIRECTION_RTL)
和 TTF_SetFontScriptName(ttf_font, "arSA\0")
都返回 0,表示成功。
这是我期望的文本显示方式:
它是这样出现的:
谁能告诉我我做错了什么?
编辑:最小可重现示例: (改编自 https://github.com/aminosbh/sdl2-ttf-sample/blob/master/src/main.c )
#include <SDL.h>
#include <SDL_ttf.h>
#include <string>
int main(int argc, char* argv[])
{
// Unused argc, argv
(void)argc;
(void)argv;
// Initialize SDL2
if (SDL_Init(SDL_INIT_VIDEO) < 0)
{
printf("SDL2 could not be initialized!\n"
"SDL2 Error: %s\n", SDL_GetError());
return 0;
}
// Initialize SDL2_ttf
TTF_Init();
// Create window
SDL_Window* window = SDL_CreateWindow("SDL2_ttf sample",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
SCREEN_WIDTH, SCREEN_HEIGHT,
SDL_WINDOW_SHOWN);
if (!window)
{
printf("Window could not be created!\n"
"SDL_Error: %s\n", SDL_GetError());
}
else
{
// Create renderer
SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
if (!renderer)
{
printf("Renderer could not be created!\n"
"SDL_Error: %s\n", SDL_GetError());
}
else
{
// Declare rect of square
SDL_Rect squareRect;
// Square dimensions: Half of the min(SCREEN_WIDTH, SCREEN_HEIGHT)
squareRect.w = MIN(SCREEN_WIDTH, SCREEN_HEIGHT) / 2;
squareRect.h = MIN(SCREEN_WIDTH, SCREEN_HEIGHT) / 2;
// Square position: In the middle of the screen
squareRect.x = SCREEN_WIDTH / 2 - squareRect.w / 2;
squareRect.y = SCREEN_HEIGHT / 2 - squareRect.h / 2;
TTF_Font* font = TTF_OpenFont(FONT_PATH, 40);
if (!font) {
printf("Unable to load font: '%s'!\n"
"SDL2_ttf Error: %s\n", FONT_PATH, TTF_GetError());
return 0;
}
const auto fontDirectionSuccess = TTF_SetFontDirection(font, TTF_DIRECTION_RTL);
const auto fontScriptNameSuccess = TTF_SetFontScriptName(font, "arSA\0");
SDL_Color textColor = { 0x00, 0x00, 0x00, 0xFF };
SDL_Color textBackgroundColor = { 0xFF, 0xFF, 0xFF, 0xFF };
SDL_Texture* text = NULL;
SDL_Rect textRect;
// Arabic text to display
const wchar_t * wstr = L"كسول الزنجبيل القط";
// Convert unicode to multibyte
int wstr_len = (int)wcslen(wstr);
int num_chars = WideCharToMultiByte(CP_UTF8, 0, wstr, wstr_len, NULL, 0, NULL, NULL);
CHAR* strTo = (CHAR*)malloc((num_chars + 1) * sizeof(CHAR));
if (strTo)
{
WideCharToMultiByte(CP_UTF8, 0, wstr, wstr_len, strTo, num_chars, NULL, NULL);
strTo[num_chars] = '\0';
}
// Render text to surface
SDL_Surface* textSurface = TTF_RenderUTF8_Blended(font, strTo, textColor);
if (!textSurface) {
printf("Unable to render text surface!\n"
"SDL2_ttf Error: %s\n", TTF_GetError());
}
else {
// Create texture from surface pixels
text = SDL_CreateTextureFromSurface(renderer, textSurface);
if (!text) {
printf("Unable to create texture from rendered text!\n"
"SDL2 Error: %s\n", SDL_GetError());
return 0;
}
// Get text dimensions
textRect.w = textSurface->w;
textRect.h = textSurface->h;
SDL_FreeSurface(textSurface);
}
textRect.x = (SCREEN_WIDTH - textRect.w) / 2;
textRect.y = squareRect.y - textRect.h - 10;
// Event loop exit flag
bool quit = false;
// Event loop
while (!quit)
{
SDL_Event e;
// Wait indefinitely for the next available event
SDL_WaitEvent(&e);
// User requests quit
if (e.type == SDL_QUIT)
{
quit = true;
}
// Initialize renderer color white for the background
SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
// Clear screen
SDL_RenderClear(renderer);
// Draw text
SDL_RenderCopy(renderer, text, NULL, &textRect);
// Update screen
SDL_RenderPresent(renderer);
}
// Destroy renderer
SDL_DestroyRenderer(renderer);
}
// Destroy window
SDL_DestroyWindow(window);
}
// Quit SDL2_ttf
TTF_Quit();
// Quit SDL
SDL_Quit();
return 0;
}
编辑 2: 我换了
TTF_SetFontDirection(font, TTF_DIRECTION_RTL);
TTF_SetFontScriptName(font, "arSA\0");
与贬低:
TTF_SetDirection(HB_DIRECTION_RTL);
TTF_SetScript(HB_SCRIPT_ARABIC);
一切正常。我怀疑“arSA\0”可能是错误的,但我能找到的唯一文档说它应该是“恰好 4 个字符的空终止字符串”,没有指示或示例是哪 4 个字符。
最佳答案
您应该使用“Arab”而不是“arSA”。
感谢评论者“1.8e9-where's-my-share m”和“skink”。
我在这里添加答案,这样您就可以接受答案。
关于c++ - 如何将(阿拉伯语)字形与 SDL-TTF v2.20 结合起来?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/73275395/