util: add util_framebuffer_min_size
[mesa.git] / src / gallium / auxiliary / util / u_framebuffer.c
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26
27 /**
28 * @file
29 * Framebuffer utility functions.
30 *
31 * @author Brian Paul
32 */
33
34
35 #include "pipe/p_screen.h"
36 #include "pipe/p_state.h"
37 #include "pipe/p_defines.h"
38 #include "util/u_inlines.h"
39
40 #include "util/u_memory.h"
41 #include "util/u_framebuffer.h"
42
43
44 /**
45 * Compare pipe_framebuffer_state objects.
46 * \return TRUE if same, FALSE if different
47 */
48 boolean
49 util_framebuffer_state_equal(const struct pipe_framebuffer_state *dst,
50 const struct pipe_framebuffer_state *src)
51 {
52 unsigned i;
53
54 if (dst->width != src->width ||
55 dst->height != src->height)
56 return FALSE;
57
58 for (i = 0; i < Elements(src->cbufs); i++) {
59 if (dst->cbufs[i] != src->cbufs[i]) {
60 return FALSE;
61 }
62 }
63
64 if (dst->nr_cbufs != src->nr_cbufs) {
65 return FALSE;
66 }
67
68 if (dst->zsbuf != src->zsbuf) {
69 return FALSE;
70 }
71
72 return TRUE;
73 }
74
75
76 /**
77 * Copy framebuffer state from src to dst, updating refcounts.
78 */
79 void
80 util_copy_framebuffer_state(struct pipe_framebuffer_state *dst,
81 const struct pipe_framebuffer_state *src)
82 {
83 unsigned i;
84
85 dst->width = src->width;
86 dst->height = src->height;
87
88 for (i = 0; i < Elements(src->cbufs); i++) {
89 pipe_surface_reference(&dst->cbufs[i], src->cbufs[i]);
90 }
91
92 dst->nr_cbufs = src->nr_cbufs;
93
94 pipe_surface_reference(&dst->zsbuf, src->zsbuf);
95 }
96
97
98 void
99 util_unreference_framebuffer_state(struct pipe_framebuffer_state *fb)
100 {
101 unsigned i;
102
103 for (i = 0; i < fb->nr_cbufs; i++) {
104 pipe_surface_reference(&fb->cbufs[i], NULL);
105 }
106
107 pipe_surface_reference(&fb->zsbuf, NULL);
108
109 fb->width = fb->height = 0;
110 fb->nr_cbufs = 0;
111 }
112
113
114 /* Where multiple sizes are allowed for framebuffer surfaces, find the
115 * minimum width and height of all bound surfaces.
116 */
117 boolean
118 util_framebuffer_min_size(const struct pipe_framebuffer_state *fb,
119 unsigned *width,
120 unsigned *height)
121 {
122 unsigned w = ~0;
123 unsigned h = ~0;
124 unsigned i;
125
126 for (i = 0; i < fb->nr_cbufs; i++) {
127 w = MIN2(w, fb->cbufs[i]->width);
128 h = MIN2(h, fb->cbufs[i]->height);
129 }
130
131 if (fb->zsbuf) {
132 w = MIN2(w, fb->zsbuf->width);
133 h = MIN2(h, fb->zsbuf->height);
134 }
135
136 if (w == ~0) {
137 *width = 0;
138 *height = 0;
139 return FALSE;
140 }
141 else {
142 *width = w;
143 *height = h;
144 return TRUE;
145 }
146 }