c - stb_truetype.h 和 SDL2 更改字体颜色

Question

我正在使用 stb_truetype.h 和 SDL2 来渲染文本。有没有简单的方法来改变字体颜色？这是我所拥有的(文本是一个 char*):

while (*text) {
    if (*text >= 32 && *text < 128) {
      stbtt_aligned_quad q;
      stbtt_GetBakedQuad(font->cdata, 512, 512, *text - 32, &x, &y, &q, 1);
      SDL_Rect src_rect = {.x = (int)512 * q.s0 - 1,
                           .y = (int)512 * (q.t0) - 1,
                           .w = (int)512 * (q.s1 - q.s0) + 1,
                           .h = (int)512 * (q.t1 - q.t0) + 1};
      SDL_Rect dst_rect = {
          .x = q.x0, .y = q.y0, .w = q.x1 - q.x0, .h = q.y1 - q.y0};


      // Has no effect because I am just grabbing a rect from the font data.
      SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
      // Always renders the font white.
      SDL_RenderCopy(renderer, font->texture, &src_rect, &dst_rect);
    }
    ++text;
}

我希望能够以不同的颜色呈现字体。现在字体始终是白色的。

Answer 1

找到了一种方法来做到这一点，使用 SDL_SetTextureColorMod : ( https://wiki.libsdl.org/SDL_SetTextureColorMod )

SDL_SetTextureColorMod(font->texture, 255, 0, 0);

例如将字体变成红色。

我使用这个的原始代码:

while (*text) {
    if (*text >= 32 && *text < 128) {
      stbtt_aligned_quad q;
      stbtt_GetBakedQuad(font->cdata, 512, 512, *text - 32, &x, &y, &q, 1);
      SDL_Rect src_rect = {.x = (int)512 * q.s0 - 1,
                           .y = (int)512 * (q.t0) - 1,
                           .w = (int)512 * (q.s1 - q.s0) + 1,
                           .h = (int)512 * (q.t1 - q.t0) + 1};
      SDL_Rect dst_rect = {
          .x = q.x0, .y = q.y0, .w = q.x1 - q.x0, .h = q.y1 - q.y0};

      // set the font texture to display red.
      SDL_SetTextureColorMod(font->texture, 255, 0, 0);
      SDL_RenderCopy(renderer, font->texture, &src_rect, &dst_rect);
    }
    ++text;
}