[SeaBIOS] Re: [PATCH 3/5] lodepng: reduce warnings

[Daniel Maslowski]

Sure :)

We're passing width and height as int pointers to obtain the image
dimensions and then try to find a matching video mode. While lodepng uses
unsigned ints, that would always give us warnings. This is a simple way of
addressing that issue. We can expect fairly small numbers, so the sign
shouldn't matter here.

I also wrote patches to allow images smaller than the screen resolution to
center them and fill the paddings with black. I believe that makes more
sense these days, avoiding mode switches entirely if possible. I'll send
those some other time. :)

On Mon, Nov 4, 2019, 3:28 PM Philippe Mathieu-Daudé 
wrote:
> Hi Daniel,
>
> On 10/29/19 6:42 PM, [e-mail] wrote:
> > From: Daniel Maslowski
>
> Can you explain the rational of this patch?
> In particular why use signed vs unsigned.
>
> Thanks,
>
> Phil.
> > Signed-off-by: Daniel Maslowski
> >
> > src/lodepng.c | 12 ++++++------
> >   1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/src/lodepng.c b/src/lodepng.c
> > index d9c8443..490fc8e 100644
> > --- a/src/lodepng.c
> > +++ b/src/lodepng.c
> > @@ -1925,7 +1925,7 @@ static void Adam7_getpassvalues(unsigned passw[7],
>
> unsigned passh[7], size_t fil
> > /*
>
> //////////////////////////////////////////////////////////////////////////
> */
> > /*read the information from the header and store it in the
>
> LodePNGInfo. return value is error*/
> > -unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
> > +unsigned lodepng_inspect(int* w, int* h, LodePNGState* state,
> >                            const unsigned char* in, size_t insize) {
> >     unsigned width, height;
> >     LodePNGInfo* info = &state->info_png;
> > @@ -2275,7 +2275,7 @@ unsigned lodepng_inspect_chunk(LodePNGState*
>
> state, size_t pos,
> > }
> >
> > /*read a PNG, the result will be in the same color type as the PNG
>
> (hence "generic")*/
> > -static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
> > +static void decodeGeneric(unsigned char** out, int* w, int* h,
> >                             LodePNGState* state,
> >                             const unsigned char* in, size_t insize) {
> >     unsigned char IEND = 0;
> > @@ -2403,7 +2403,7 @@ static void decodeGeneric(unsigned char** out,
>
> unsigned* w, unsigned* h,
> > ucvector_cleanup(&scanlines);
> >
> > }
> >
> > -unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
> > +unsigned lodepng_decode(unsigned char** out, int* w, int* h,
> >                           LodePNGState* state,
> >                           const unsigned char* in, size_t insize) {
> >     *out = 0;
> > @@ -2441,7 +2441,7 @@ unsigned lodepng_decode(unsigned char** out,
>
> unsigned* w, unsigned* h,
> > return state->error;
> >
> > }
> >
> > -unsigned lodepng_decode_memory(unsigned char** out, unsigned* w,
>
> unsigned* h, const unsigned char* in,
> > +unsigned lodepng_decode_memory(unsigned char** out, int* w, int* h,
>
> const unsigned char* in,
> >                              size_t insize, LodePNGColorType
>
> colortype, unsigned bitdepth) {
> > unsigned error;
> > LodePNGState state;
> >
> > @@ -2453,11 +2453,11 @@ unsigned lodepng_decode_memory(unsigned char**
>
> out, unsigned* w, unsigned* h, co
> > return error;
> >
> > }
> >
> > -unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned*
>
> h, const unsigned char* in, size_t insize) {
> > +unsigned lodepng_decode32(unsigned char** out, int* w, int* h, const
>
> unsigned char* in, size_t insize) {
> > return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
> >
> > }
> >
> > -unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned*
>
> h, const unsigned char* in, size_t insize) {
> > +unsigned lodepng_decode24(unsigned char** out, int* w, int* h, const
>
> unsigned char* in, size_t insize) {
> > return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
> >
> > }