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

// all these must be powers of two
#define TC_WIDTH  256
#define TC_HEIGHT 256
#define TC_ROUND  4

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

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

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

#include <glib.h>

typedef struct tc_texture {
  struct tc_texture *next;
  GLuint name;
  int avail;
} 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 ()
{
  int i;

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

  while (first_texture)
    {
      tc_texture *next = first_texture->next;
      glDeleteTextures (1, &first_texture->name);
      g_slice_free (tc_texture, first_texture);
      first_texture = 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;
          glGenTextures (1, &match->name);
          match->avail = TC_HEIGHT;

          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:	1.1
Committed:	Tue Jul 4 23:23:32 2006 UTC (20 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
Log Message:	Get rid of cairo completely (yay!) and of ft2 factually (still need the library as it included pangofc), by introducing a custom pango opengl renderer. Text rendering now no longer requires the distinction between rgba and grayscale modes, requires much less texture space and memory, and is faster on accelerated hardware (and possibly with software rendering, too). All at the cost of only 1200 lines or so.
#	Content
1	// all these must be powers of two
2	#define TC_WIDTH 256
3	#define TC_HEIGHT 256
4	#define TC_ROUND 4
5
6	typedef struct {
7	GLuint name;
8	int x, y, w, h;
9	} tc_area;
10
11	void tc_get (tc_area *area, int width, int height);
12	void tc_put (tc_area *area);
13	void tc_clear ();
14
15	/////////////////////////////////////////////////////////////////////////////
16
17	#include <glib.h>
18
19	typedef struct tc_texture {
20	struct tc_texture *next;
21	GLuint name;
22	int avail;
23	} tc_texture;
24
25	typedef struct tc_slice {
26	GLuint name;
27	int avail, y;
28	} tc_slice;
29
30	static tc_slice slices[TC_HEIGHT / TC_ROUND];
31	static tc_texture *first_texture;
32
33	void
34	tc_clear ()
35	{
36	int i;
37
38	for (i = TC_HEIGHT / TC_ROUND; i--; )
39	slices [i].name = 0;
40
41	while (first_texture)
42	{
43	tc_texture *next = first_texture->next;
44	glDeleteTextures (1, &first_texture->name);
45	g_slice_free (tc_texture, first_texture);
46	first_texture = next;
47	}
48	}
49
50	void
51	tc_get (tc_area *area, int width, int height)
52	{
53	int slice_height = MIN (height + TC_ROUND - 1, TC_HEIGHT) & ~(TC_ROUND - 1);
54	tc_slice *slice = slices + slice_height / TC_ROUND;
55
56	area->w = width;
57	area->h = height;
58
59	width = MIN (width, TC_WIDTH);
60
61	if (!slice->name \|\| slice->avail < width)
62	{
63	// try to find a texture with enough space
64	tc_texture tex, match = 0;
65
66	for (tex = first_texture; tex; tex = tex->next)
67	if (tex->avail >= slice_height && (!match \|\| match->avail > tex->avail))
68	match = tex;
69
70	// create a new texture if necessary
71	if (!match)
72	{
73	match = g_slice_new (tc_texture);
74	match->next = first_texture;
75	first_texture = match;
76	glGenTextures (1, &match->name);
77	match->avail = TC_HEIGHT;
78
79	glBindTexture (GL_TEXTURE_2D, match->name);
80	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
81	glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
82	glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, 0);
83	}
84
85	match->avail -= slice_height;
86
87	slice->name = match->name;
88	slice->avail = TC_WIDTH;
89	slice->y = match->avail;
90	}
91
92	slice->avail -= width;
93
94	area->name = slice->name;
95	area->x = slice->avail;
96	area->y = slice->y;
97	}
98
99	void
100	tc_put (tc_area *area)
101	{
102	// our management is too primitive to support this operation yet
103	}