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view docs/man3/SDL_CreateRGBSurface.3 @ 1192:54aa9aa32327
To: sdl@libsdl.org
From: Christian Walther <cwalther@gmx.ch>
Date: Fri, 18 Nov 2005 23:39:02 +0100
Subject: [SDL] Mouse position bugs on Mac OS X
The attached patch fixes a few bugs in SDL related to the mouse position
in windowed mode on Mac OS X, reproduced using the attached minimal test
program - at least here on 10.3.9, with SDL CVS from today. Could anyone
test whether the bugs exist and are fixed by the patch on 10.2 and 10.4?
1. When using OpenGL, the vertical mouse positions obtained through
events or SDL_GetMouseState() are off by one.
2. When using OpenGL, SDL_WarpMouse() inverts the y coordinate.
3. Clicks on the topmost pixel row of the window are not recognized.
1 and 2 do not occur in non-OpenGL mode, while 3 does. All three only
occur in windowed mode, not in fullscreen.
The cause for 1 and 3 is that in Cocoa, "the location of the mouse"
seems to be defined as "the location of the top left corner of the mouse
pointer's hot pixel" (this is not documented, it's just what I found out
here), which together with the fact that Cocoa's usual y coordinates
start at the bottom and increase upwards means that the y coordinate of
the mouse runs from 1 to h, not from 0 to h-1, in a window of height h.
If it does work on 10.2 and 10.4 (I'll try to test it as soon as I can,
but at the moment all I have at hand is 10.3.9), can this be applied to
the CVS?
-Christian
To: sdl@libsdl.org
From: Christian Walther <cwalther@gmx.ch>
Date: Mon, 28 Nov 2005 10:41:51 +0100
Subject: [SDL] Re: Mouse position bugs on Mac OS X
I wrote:
> I'll try to test it as soon as I can, but at the moment all I have at hand is 10.3.9
So, here are the results of my tests (with patched and unpatched
frameworks compiled with Xcode 1.5 (gcc 3.3) on 10.3.9):
On 10.1.5, my test program doesn't run because of "Undefined symbols:
SDL undefined reference to _CGMainDisplayID expected to be defined in
Carbon". I guess not supporting 10.1 was a deliberate decision then and
that's OK with me.
On 10.2.8, 10.3.9, and 10.4.0, the bugs exist as described in my
original post and are fixed by my patch. That is, there is no difference
between pre/post 10.3 and the patched version works correctly in all
combinations of GL/non-GL and windowed/fullscreen.
I therefore recommend the patch for inclusion.
-Christian
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Mon, 28 Nov 2005 13:58:26 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
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.TH "SDL_CreateRGBSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_CreateRGBSurface\- Create an empty SDL_Surface .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_Surface *\fBSDL_CreateRGBSurface\fP\fR(\fBUint32 flags, int width, int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask\fR); .SH "DESCRIPTION" .PP Allocate an empty surface (must be called after \fISDL_SetVideoMode\fR) .PP If \fBdepth\fR is 8 bits an empty palette is allocated for the surface, otherwise a \&'packed-pixel\&' \fI\fBSDL_PixelFormat\fR\fR is created using the \fB[RGBA]mask\fR\&'s provided (see \fI\fBSDL_PixelFormat\fR\fR)\&. The \fBflags\fR specifies the type of surface that should be created, it is an OR\&'d combination of the following possible values\&. .TP 20 \fBSDL_SWSURFACE\fP SDL will create the surface in system memory\&. This improves the performance of pixel level access, however you may not be able to take advantage of some types of hardware blitting\&. .TP 20 \fBSDL_HWSURFACE\fP SDL will attempt to create the surface in video memory\&. This will allow SDL to take advantage of Video->Video blits (which are often accelerated)\&. .TP 20 \fBSDL_SRCCOLORKEY\fP This flag turns on colourkeying for blits from this surface\&. If \fBSDL_HWSURFACE\fP is also specified and colourkeyed blits are hardware-accelerated, then SDL will attempt to place the surface in video memory\&. Use \fI\fBSDL_SetColorKey\fP\fR to set or clear this flag after surface creation\&. .TP 20 \fBSDL_SRCALPHA\fP This flag turns on alpha-blending for blits from this surface\&. If \fBSDL_HWSURFACE\fP is also specified and alpha-blending blits are hardware-accelerated, then the surface will be placed in video memory if possible\&. Use \fI\fBSDL_SetAlpha\fP\fR to set or clear this flag after surface creation\&. .PP .RS \fBNote: .PP If an alpha-channel is specified (that is, if \fBAmask\fR is nonzero), then the \fBSDL_SRCALPHA\fP flag is automatically set\&. You may remove this flag by calling \fI\fBSDL_SetAlpha\fP\fR after surface creation\&. .RE .SH "RETURN VALUE" .PP Returns the created surface, or \fBNULL\fR upon error\&. .SH "EXAMPLE" .PP .nf \f(CW /* Create a 32-bit surface with the bytes of each pixel in R,G,B,A order, as expected by OpenGL for textures */ SDL_Surface *surface; Uint32 rmask, gmask, bmask, amask; /* SDL interprets each pixel as a 32-bit number, so our masks must depend on the endianness (byte order) of the machine */ #if SDL_BYTEORDER == SDL_BIG_ENDIAN rmask = 0xff000000; gmask = 0x00ff0000; bmask = 0x0000ff00; amask = 0x000000ff; #else rmask = 0x000000ff; gmask = 0x0000ff00; bmask = 0x00ff0000; amask = 0xff000000; #endif surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height, 32, rmask, gmask, bmask, amask); if(surface == NULL) { fprintf(stderr, "CreateRGBSurface failed: %s ", SDL_GetError()); exit(1); }\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_CreateRGBSurfaceFrom\fP\fR, \fI\fBSDL_FreeSurface\fP\fR, \fI\fBSDL_SetVideoMode\fP\fR, \fI\fBSDL_LockSurface\fP\fR, \fI\fBSDL_PixelFormat\fR\fR, \fI\fBSDL_Surface\fR\fR \fI\fBSDL_SetAlpha\fP\fR \fI\fBSDL_SetColorKey\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01