8f1edcb6ed
Cogl now assumes non-power-of-two textures are supported if the GL version is >= 2.0 so the disable-npots utility should also change the GL version.
157 lines
3.9 KiB
C
157 lines
3.9 KiB
C
/*
|
|
* This file can be build as a shared library and then used as an
|
|
* LD_PRELOAD to fake a system where NPOTs is not supported. It simply
|
|
* overrides glGetString and removes the extension strings.
|
|
*/
|
|
|
|
/* This is just included to get the right GL header */
|
|
#include <cogl/cogl.h>
|
|
|
|
#include <dlfcn.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
#include <ctype.h>
|
|
#include <stdlib.h>
|
|
|
|
/* If RTLD_NEXT isn't available then try just using NULL */
|
|
#ifdef RTLD_NEXT
|
|
#define LIB_HANDLE RTLD_NEXT
|
|
#else
|
|
#define LIB_HANDLE NULL
|
|
#endif
|
|
|
|
typedef const GLubyte * (* GetStringFunc) (GLenum name);
|
|
|
|
static const char * const bad_strings[]
|
|
= { "GL_ARB_texture_non_power_of_two",
|
|
"GL_ARB_texture_rectangle",
|
|
"GL_EXT_texture_rectangle",
|
|
NULL };
|
|
|
|
static gboolean
|
|
get_gl_version (const gchar *version_string,
|
|
int *major_out, int *minor_out)
|
|
{
|
|
const char *major_end, *minor_end;
|
|
int major = 0, minor = 0;
|
|
|
|
if (version_string == NULL)
|
|
return FALSE;
|
|
|
|
/* Extract the major number */
|
|
for (major_end = version_string; *major_end >= '0'
|
|
&& *major_end <= '9'; major_end++)
|
|
major = (major * 10) + *major_end - '0';
|
|
/* If there were no digits or the major number isn't followed by a
|
|
dot then it is invalid */
|
|
if (major_end == version_string || *major_end != '.')
|
|
return FALSE;
|
|
|
|
/* Extract the minor number */
|
|
for (minor_end = major_end + 1; *minor_end >= '0'
|
|
&& *minor_end <= '9'; minor_end++)
|
|
minor = (minor * 10) + *minor_end - '0';
|
|
/* If there were no digits or there is an unexpected character then
|
|
it is invalid */
|
|
if (minor_end == major_end + 1
|
|
|| (*minor_end && *minor_end != ' ' && *minor_end != '.'))
|
|
return FALSE;
|
|
|
|
*major_out = major;
|
|
*minor_out = minor;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
const GLubyte *
|
|
glGetString (GLenum name)
|
|
{
|
|
const gchar *ret = NULL;
|
|
static GetStringFunc func = NULL;
|
|
static gchar *extensions = NULL;
|
|
static gchar *version = NULL;
|
|
|
|
if (func == NULL
|
|
&& (func = (GetStringFunc) dlsym (LIB_HANDLE, "glGetString")) == NULL)
|
|
fprintf (stderr, "dlsym: %s\n", dlerror ());
|
|
else if (func == glGetString)
|
|
fprintf (stderr, "dlsym returned the wrapper of glGetString\n");
|
|
else
|
|
{
|
|
ret = (const gchar *) (* func) (name);
|
|
|
|
if (name == GL_EXTENSIONS)
|
|
{
|
|
if (extensions == NULL)
|
|
{
|
|
if ((extensions = strdup ((char *) ret)) == NULL)
|
|
fprintf (stderr, "strdup: %s\n", strerror (errno));
|
|
else
|
|
{
|
|
gchar *dst = extensions, *src = extensions;
|
|
|
|
while (1)
|
|
{
|
|
const char * const *str = bad_strings;
|
|
gchar *end;
|
|
|
|
while (isspace (*src))
|
|
*(dst++) = *(src++);
|
|
|
|
if (*src == 0)
|
|
break;
|
|
|
|
for (end = src + 1; *end && !isspace (*end); end++);
|
|
|
|
while (*str && strncmp ((char *) src, *str, end - src))
|
|
str++;
|
|
|
|
if (*str == NULL)
|
|
{
|
|
memcpy (dst, src, end - src);
|
|
dst += end - src;
|
|
}
|
|
|
|
src = end;
|
|
}
|
|
|
|
*dst = '\0';
|
|
}
|
|
}
|
|
|
|
ret = extensions;
|
|
}
|
|
else if (name == GL_VERSION)
|
|
{
|
|
int gl_major, gl_minor;
|
|
|
|
/* If the GL version is >= 2.0 then Cogl will assume it
|
|
supports NPOT textures anyway so we need to tweak it */
|
|
if (get_gl_version ((const gchar *) ret,
|
|
&gl_major, &gl_minor) && gl_major >= 2)
|
|
{
|
|
if (version == NULL)
|
|
{
|
|
const gchar *tail = strchr (ret, ' ');
|
|
if (tail)
|
|
{
|
|
version = malloc (3 + strlen (tail) + 1);
|
|
if (version)
|
|
{
|
|
strcpy (version + 3, tail);
|
|
memcpy (version, "1.9", 3);
|
|
}
|
|
}
|
|
else
|
|
version = strdup ("1.9");
|
|
}
|
|
|
|
ret = version;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (const GLubyte *) ret;
|
|
}
|