cf.schmorp.de/Deliantra-Client/texcache.c

// all these must be powers of two
// width and height better be <=256 as we use bytes in the rendercache
#define TC_WIDTH  256
#define TC_HEIGHT 256
#define TC_ROUND  4

typedef struct {
  GLuint name;
  int x, y, w, h;
} tc_area;

extern int tc_generation;

void tc_get (tc_area *area, int width, int height);
void tc_put (tc_area *area);
void tc_clear ();

/////////////////////////////////////////////////////////////////////////////

#include <glib.h>

int tc_generation;

typedef struct tc_texture {
  struct tc_texture *next;
  GLuint name;
  int avail;
  char *saved; /* stores saved texture data */
} tc_texture;

typedef struct tc_slice {
  GLuint name;
  int avail, y;
} tc_slice;

static tc_slice slices[TC_HEIGHT / TC_ROUND];
static tc_texture *first_texture;

void
tc_clear (void)
{
  int i;

  for (i = TC_HEIGHT / TC_ROUND; i--; )
    slices [i].name = 0;

  while (first_texture)
    {
      tc_texture *next = first_texture->next;
      del_texture (first_texture->name);
      g_slice_free (tc_texture, first_texture);
      first_texture = next;
    }

  ++tc_generation;
}

void
tc_backup (void)
{
  tc_texture *tex = first_texture;
  while (tex)
    {
      tex->saved = g_slice_alloc (TC_WIDTH * TC_HEIGHT);

      glBindTexture (GL_TEXTURE_2D, tex->name);
      glGetTexImage (GL_TEXTURE_2D, 0, GL_ALPHA, GL_UNSIGNED_BYTE, tex->saved);

      tex = tex->next;
    }
}

void
tc_restore (void)
{
  tc_texture *tex = first_texture;

  while (tex)
    {
      glBindTexture (GL_TEXTURE_2D, tex->name);
      glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
      glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
      glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, tex->saved);

      g_slice_free1 (TC_WIDTH * TC_HEIGHT, tex->saved);
      tex->saved = 0;

      tex = tex->next;
    }
}

void
tc_get (tc_area *area, int width, int height)
{
  int slice_height = MIN (height + TC_ROUND - 1, TC_HEIGHT) & ~(TC_ROUND - 1);
  tc_slice *slice = slices + slice_height / TC_ROUND;

  area->w = width;
  area->h = height;

  width = MIN (width, TC_WIDTH);

  if (!slice->name || slice->avail < width)
    {
      // try to find a texture with enough space
      tc_texture *tex, *match = 0;

      for (tex = first_texture; tex; tex = tex->next)
        if (tex->avail >= slice_height && (!match || match->avail > tex->avail))
          match = tex;

      // create a new texture if necessary
      if (!match)
        {
          match = g_slice_new (tc_texture);
          match->next   = first_texture;
          first_texture = match;
          match->name   = gen_texture ();
          match->avail  = TC_HEIGHT;
          match->saved  = 0;

          glBindTexture (GL_TEXTURE_2D, match->name);
          glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
          glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
          glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, 0);
        }

      match->avail -= slice_height;

      slice->name  = match->name;
      slice->avail = TC_WIDTH;
      slice->y     = match->avail;
    }

  slice->avail -= width;

  area->name = slice->name;
  area->x    = slice->avail;
  area->y    = slice->y;
}

void
tc_put (tc_area *area)
{
  // our management is too primitive to support this operation yet
}
Revision:	1.5
Committed:	Tue Dec 25 18:58:32 2007 UTC (18 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.4:	+40 -4 lines
Log Message:	save/restore textures in a safer way, also save/restore glyph cache
#	User	Rev	Content
1	root	1.1	// all these must be powers of two
2	root	1.4	// width and height better be <=256 as we use bytes in the rendercache
3	root	1.1	#define TC_WIDTH 256
4			#define TC_HEIGHT 256
5			#define TC_ROUND 4
6
7			typedef struct {
8			GLuint name;
9			int x, y, w, h;
10			} tc_area;
11
12	root	1.2	extern int tc_generation;
13
14	root	1.1	void tc_get (tc_area *area, int width, int height);
15			void tc_put (tc_area *area);
16			void tc_clear ();
17
18			/////////////////////////////////////////////////////////////////////////////
19
20			#include <glib.h>
21
22	root	1.2	int tc_generation;
23
24	root	1.1	typedef struct tc_texture {
25			struct tc_texture *next;
26			GLuint name;
27			int avail;
28	root	1.5	char saved; / stores saved texture data */
29	root	1.1	} tc_texture;
30
31			typedef struct tc_slice {
32			GLuint name;
33			int avail, y;
34			} tc_slice;
35
36			static tc_slice slices[TC_HEIGHT / TC_ROUND];
37			static tc_texture *first_texture;
38
39			void
40	root	1.5	tc_clear (void)
41	root	1.1	{
42			int i;
43
44			for (i = TC_HEIGHT / TC_ROUND; i--; )
45			slices [i].name = 0;
46
47			while (first_texture)
48			{
49			tc_texture *next = first_texture->next;
50	root	1.3	del_texture (first_texture->name);
51	root	1.1	g_slice_free (tc_texture, first_texture);
52			first_texture = next;
53			}
54	root	1.2
55			++tc_generation;
56	root	1.1	}
57
58			void
59	root	1.5	tc_backup (void)
60			{
61			tc_texture *tex = first_texture;
62			while (tex)
63			{
64			tex->saved = g_slice_alloc (TC_WIDTH * TC_HEIGHT);
65
66			glBindTexture (GL_TEXTURE_2D, tex->name);
67			glGetTexImage (GL_TEXTURE_2D, 0, GL_ALPHA, GL_UNSIGNED_BYTE, tex->saved);
68
69			tex = tex->next;
70			}
71			}
72
73			void
74			tc_restore (void)
75			{
76			tc_texture *tex = first_texture;
77
78			while (tex)
79			{
80			glBindTexture (GL_TEXTURE_2D, tex->name);
81			glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
82			glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
83			glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, tex->saved);
84
85			g_slice_free1 (TC_WIDTH * TC_HEIGHT, tex->saved);
86			tex->saved = 0;
87
88			tex = tex->next;
89			}
90			}
91
92			void
93	root	1.1	tc_get (tc_area *area, int width, int height)
94			{
95			int slice_height = MIN (height + TC_ROUND - 1, TC_HEIGHT) & ~(TC_ROUND - 1);
96			tc_slice *slice = slices + slice_height / TC_ROUND;
97
98			area->w = width;
99			area->h = height;
100
101			width = MIN (width, TC_WIDTH);
102
103			if (!slice->name \|\| slice->avail < width)
104			{
105			// try to find a texture with enough space
106			tc_texture tex, match = 0;
107
108			for (tex = first_texture; tex; tex = tex->next)
109			if (tex->avail >= slice_height && (!match \|\| match->avail > tex->avail))
110			match = tex;
111
112			// create a new texture if necessary
113			if (!match)
114			{
115			match = g_slice_new (tc_texture);
116	root	1.5	match->next = first_texture;
117	root	1.1	first_texture = match;
118	root	1.5	match->name = gen_texture ();
119			match->avail = TC_HEIGHT;
120			match->saved = 0;
121	root	1.1
122			glBindTexture (GL_TEXTURE_2D, match->name);
123			glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
124			glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
125			glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, 0);
126			}
127
128			match->avail -= slice_height;
129
130			slice->name = match->name;
131			slice->avail = TC_WIDTH;
132			slice->y = match->avail;
133			}
134
135			slice->avail -= width;
136
137			area->name = slice->name;
138			area->x = slice->avail;
139			area->y = slice->y;
140			}
141
142			void
143			tc_put (tc_area *area)
144			{
145			// our management is too primitive to support this operation yet
146			}