Opens a font from an SDL_RWops with target resolutions (in DPI).
int freesrc, int ptsize, unsigned int hdpi, unsigned int vdpi);TTF_Font * TTF_OpenFontDPIRW(SDL_RWops *src,
|src||an SDL_RWops to provide a font file's data.|
|freesrc||non-zero to close the RWops before returning, zero to leave it open.|
|ptsize||point size to use for the newly-opened font.|
|hdpi||the target horizontal DPI.|
|vdpi||the target vertical DPI.|
Returns a valid TTF_Font, or NULL on error.
DPI scaling only applies to scalable fonts (e.g. TrueType).
Some .fon fonts will have several sizes embedded in the file, so the point size becomes the index of choosing which size. If the value is too high, the last indexed size will be the default.
freesrc is non-zero, the RWops will be closed before returning, whether this function succeeds or not. SDL_ttf reads everything it needs from the RWops during this call in any case.
When done with the returned TTF_Font, use TTF_CloseFont() to dispose of it.
This function is available since SDL_ttf 2.0.18.