Mercurial > sdl-ios-xcode
annotate docs/html/guidepreface.html @ 876:9e84d106ec19
(Said Max Horn on the SDL mailing list...)
Hi folks,
based on Eric Wing's patch, I created the attached patch which fixes
the OpenGL coordinate inversion bug in SDL. It works fine over here on
10.3 with Ryan's test program (which I also attached).
There is another change in it: I removed the "- 1" in the two lines
using CGDisplayPixelsHigh()... while I understand from a logical point
of view why they *should* be correct, I checked the actual values
computed that way, and they were off-by-one. After removing the " - 1",
the returned mouse coordinates are correct. I checked this by moving
the mouse to the screen top/bottom in fullscreen mode, BTW. With the
change, the proper values 0 and 479 are returned (in 640x480 mode).
Sam, you may still want to test on 10.1, it's very simple using Ryan's
minimal test code :-)
Cheers,
Max
(Here is the reproduction case for revision history's sake...)
/*
* To compile:
* gcc -o test test.c `sdl-config --cflags` `sdl-config --libs` -framework OpenGL
*
* --ryan.
*/
#include <stdio.h>
#include "SDL.h"
#include "SDL_opengl.h"
int main(int argc, char **argv)
{
Uint32 flags = SDL_OPENGL /* | SDL_FULLSCREEN */;
SDL_Surface *screen;
SDL_Event event;
int done = 0;
GLfloat ratio;
SDL_Init(SDL_INIT_VIDEO);
SDL_ShowCursor(0);
if ((argv[1]) && (strcmp(argv[1], "--grab") == 0))
SDL_WM_GrabInput(SDL_GRAB_ON);
screen = SDL_SetVideoMode(640, 480, 0, flags);
if (!screen)
return(42);
ratio = ((GLfloat) screen->w) / ((GLfloat) screen->h);
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glClearDepth( 1.0f );
glEnable( GL_DEPTH_TEST );
glDepthFunc( GL_LEQUAL );
glViewport( 0, 0, screen->w, screen->h);
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 45.0f, ratio, 0.1f, 100.0f );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
SDL_GL_SwapBuffers();
// eh, close enough.
#define MAX_X 6.12
#define MAX_Y 4.50
while (!done)
{
int x, y;
GLfloat glx, gly;
if (!SDL_WaitEvent(&event))
break;
switch (event.type)
{
case SDL_KEYUP:
if (event.key.keysym.sym == SDLK_ESCAPE)
done = 1;
break;
}
SDL_GetMouseState(&x, &y);
glx = ((((GLfloat) x) / ((GLfloat) screen->w)) - 0.5f) * MAX_X;
gly = ((((GLfloat) y) / ((GLfloat) screen->h)) - 0.5f) * MAX_Y;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(glx,-gly,-6.0f);
glBegin(GL_TRIANGLES);
glColor3f(1,0,0); glVertex3f( 0.00f, 0.25f, 0.00f);
glColor3f(0,1,0); glVertex3f(-0.25f, -0.25f, 0.00f);
glColor3f(0,0,1); glVertex3f( 0.25f, -0.25f, 0.00f);
glEnd();
SDL_GL_SwapBuffers();
}
SDL_Quit();
return(0);
}
/* end of test.c ... */
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Mon, 22 Mar 2004 09:38:20 +0000 |
parents | 355632dca928 |
children |
rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >Preface</TITLE | |
5 ><META | |
6 NAME="GENERATOR" | |
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ |
0 | 8 "><LINK |
9 REL="HOME" | |
10 TITLE="SDL Library Documentation" | |
11 HREF="index.html"><LINK | |
12 REL="UP" | |
13 TITLE="SDL Guide" | |
14 HREF="guide.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL Guide" | |
17 HREF="guide.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="About SDLdoc" | |
20 HREF="guideaboutsdldoc.html"></HEAD | |
21 ><BODY | |
22 CLASS="PREFACE" | |
23 BGCOLOR="#FFF8DC" | |
24 TEXT="#000000" | |
25 LINK="#0000ee" | |
26 VLINK="#551a8b" | |
27 ALINK="#ff0000" | |
28 ><DIV | |
29 CLASS="NAVHEADER" | |
30 ><TABLE | |
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31 SUMMARY="Header navigation table" |
0 | 32 WIDTH="100%" |
33 BORDER="0" | |
34 CELLPADDING="0" | |
35 CELLSPACING="0" | |
36 ><TR | |
37 ><TH | |
38 COLSPAN="3" | |
39 ALIGN="center" | |
40 >SDL Library Documentation</TH | |
41 ></TR | |
42 ><TR | |
43 ><TD | |
44 WIDTH="10%" | |
45 ALIGN="left" | |
46 VALIGN="bottom" | |
47 ><A | |
48 HREF="guide.html" | |
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49 ACCESSKEY="P" |
0 | 50 >Prev</A |
51 ></TD | |
52 ><TD | |
53 WIDTH="80%" | |
54 ALIGN="center" | |
55 VALIGN="bottom" | |
56 ></TD | |
57 ><TD | |
58 WIDTH="10%" | |
59 ALIGN="right" | |
60 VALIGN="bottom" | |
61 ><A | |
62 HREF="guideaboutsdldoc.html" | |
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63 ACCESSKEY="N" |
0 | 64 >Next</A |
65 ></TD | |
66 ></TR | |
67 ></TABLE | |
68 ><HR | |
69 ALIGN="LEFT" | |
70 WIDTH="100%"></DIV | |
71 ><DIV | |
72 CLASS="PREFACE" | |
73 ><H1 | |
74 ><A | |
75 NAME="GUIDEPREFACE" | |
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76 ></A |
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77 >Preface</H1 |
0 | 78 ><DIV |
79 CLASS="TOC" | |
80 ><DL | |
81 ><DT | |
82 ><B | |
83 >Table of Contents</B | |
84 ></DT | |
85 ><DT | |
86 ><A | |
87 HREF="guidepreface.html#GUIDEABOUTSDL" | |
88 >About SDL</A | |
89 ></DT | |
90 ><DT | |
91 ><A | |
92 HREF="guideaboutsdldoc.html" | |
93 >About SDLdoc</A | |
94 ></DT | |
95 ><DT | |
96 ><A | |
97 HREF="guidecredits.html" | |
98 >Credits</A | |
99 ></DT | |
100 ></DL | |
101 ></DIV | |
102 ><DIV | |
103 CLASS="SECT1" | |
104 ><H1 | |
105 CLASS="SECT1" | |
106 ><A | |
107 NAME="GUIDEABOUTSDL" | |
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108 ></A |
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109 >About SDL</H1 |
0 | 110 ><P |
111 >The SDL library is designed to make it easy to write games that run on Linux, *BSD, MacOS, Win32 and BeOS using the various native high-performance media interfaces, (for video, audio, etc) and presenting a single source-code level API to your application. SDL is a fairly low level API, but using it, completely portable applications can be written with a great deal of flexibility.</P | |
112 ></DIV | |
113 ></DIV | |
114 ><DIV | |
115 CLASS="NAVFOOTER" | |
116 ><HR | |
117 ALIGN="LEFT" | |
118 WIDTH="100%"><TABLE | |
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119 SUMMARY="Footer navigation table" |
0 | 120 WIDTH="100%" |
121 BORDER="0" | |
122 CELLPADDING="0" | |
123 CELLSPACING="0" | |
124 ><TR | |
125 ><TD | |
126 WIDTH="33%" | |
127 ALIGN="left" | |
128 VALIGN="top" | |
129 ><A | |
130 HREF="guide.html" | |
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131 ACCESSKEY="P" |
0 | 132 >Prev</A |
133 ></TD | |
134 ><TD | |
135 WIDTH="34%" | |
136 ALIGN="center" | |
137 VALIGN="top" | |
138 ><A | |
139 HREF="index.html" | |
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140 ACCESSKEY="H" |
0 | 141 >Home</A |
142 ></TD | |
143 ><TD | |
144 WIDTH="33%" | |
145 ALIGN="right" | |
146 VALIGN="top" | |
147 ><A | |
148 HREF="guideaboutsdldoc.html" | |
803
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149 ACCESSKEY="N" |
0 | 150 >Next</A |
151 ></TD | |
152 ></TR | |
153 ><TR | |
154 ><TD | |
155 WIDTH="33%" | |
156 ALIGN="left" | |
157 VALIGN="top" | |
158 >SDL Guide</TD | |
159 ><TD | |
160 WIDTH="34%" | |
161 ALIGN="center" | |
162 VALIGN="top" | |
163 ><A | |
164 HREF="guide.html" | |
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165 ACCESSKEY="U" |
0 | 166 >Up</A |
167 ></TD | |
168 ><TD | |
169 WIDTH="33%" | |
170 ALIGN="right" | |
171 VALIGN="top" | |
172 >About SDLdoc</TD | |
173 ></TR | |
174 ></TABLE | |
175 ></DIV | |
176 ></BODY | |
177 ></HTML | |
178 > |