This is a function that does what it says - it clears the given surface.
This just means doing a FillRect(), but it's better to use this function
because it conveys intent better.
Apparently in C, if you have `void test();`, it's completely okay to do
`test(2);`. The function will take in the argument, but just discard it
and throw it away. It's like a trash can, and a rude one at that. If you
declare it like `void test(void);`, this is prevented.
This is not a problem in C++ - doing `void test();` and `test(2);` is
guaranteed to result in a compile error (this also means that right now,
at least in all `.cpp` files, nobody is ever calling a void parameter
function with arguments and having their arguments be thrown away).
However, we may not be using C++ in the future, so I just want to lay
down the precedent that if a function takes in no arguments, you must
explicitly declare it as such.
I would've added `-Wstrict-prototypes`, but it produces an annoying
warning message saying it doesn't work in C++ mode if you're compiling
in C++ mode. So it can be added later.
This patch cleans up unnecessary exports from header files (there were
only a few), as well as adds the static keyword to all symbols that
aren't exported and are specific to a file. This helps the linker out in
not doing any unnecessary work, speeding it up and avoiding silent
symbol conflicts (otherwise two symbols with the same name (and
type/signature in C++) would quietly resolve as okay by the linker).
Neither of these were used anywhere, so to simplify the code and prevent
having potentially broken code that's never shown to be broken because
it's never tested, I'm removing these.
ScaleSurfaceSlow() uses DrawPixel() instead of SDL_FillRect() to scale a
given surface, which is slow and inefficient, and makes it less likely
that the game could be moved to SDL_Render.
Unfortunately, it has this weird -1,-1 offset, but that will be fixed in
the next commit.
So, earlier in the development of 2.0, Simon Roth (I presume)
encountered a problem: Oh no, all my backgrounds aren't appearing! And
this is because my foregroundBuffer, which contains all the drawn tiles,
is drawing complete black over it!
So he had a solution that seems ingenius, but is actually really really
hacky and super 100% NOT the proper solution. Just, take the
foregroundBuffer, iterate over each pixel, and DON'T draw any pixel
that's 0xDEADBEEF. 0xDEADBEEF is a special signal meaning "don't draw
this pixel". It is called a 'key'.
Unfortunately, this causes a bug where translucent pixels on tiles
(pixels between 0% and 100% opacity) didn't get drawn correctly. They
would be drawn against this weird blue color.
Now, in #103, I came across this weird constant and decided "hey, this
looks awfully like that weird blue color I came across, maybe if I set
it to 0x00000000, i.e. complete and transparent black, the issue will be
fixed". And it DID appear to be fixed. However, I didn't look too
closely, nor did I test it that much, and all that ended up doing was
drawing the pixels against black, which more subtly disguised the
problem with translucent pixels.
So, after some investigation, I noticed that BlitSurfaceColoured() was
drawing translucent pixels just fine. And I thought at the time that
there was something wrong with BlitSurfaceStandard(), or something.
Further along later I realized that all drawn tiles were passing through
this weird OverlaySurfaceKeyed() function. And removing it in favor of a
straight SDL_BlitSurface() produced the bug I mentioned above: Oh no,
all the backgrounds don't show up, because my foregroundBuffer is
drawing pure black over them!
Well... just... set the proper blend mode for foregroundBuffer. It
should be SDL_BLENDMODE_BLEND instead of SDL_BLENDMODE_NONE.
Then you don't have to worry about your transparency at all. If you did
it right, you won't have to resort this hacky color-keying business.
*sigh*
This function checked the intersection of rectangles, but it used floats
for some reason when its only caller used ints. There's already an
intersection function (UtilityClass::intersects()), so we should be
using that one instead in order to minimize code duplication.
Graphics::Hitest() is used for per-pixel collision detection, directly
checking the pixels of both entities' sprites. I checked with one of my
TASes and it still syncs, so I'm pretty sure this won't cause any
issues.
That's how it should be done, because the SDL headers aren't going to be
installed in this repository. The game was a bit inconsistent before but
now it isn't anymore.
