1/**************************************************************************
2 *
3 * Copyright 2019 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29/*
30 * Miscellantous state tracker utility functions, macros.
31 */
32
33
34#ifndef ST_UTIL
35#define ST_UTIL
36
37
38#include "state_tracker/st_context.h"
39
40
41#ifdef __cplusplus
42extern "C" {
43#endif
44
45
46/** For drawing quads for glClear, glDraw/CopyPixels, glBitmap, etc. */
47struct st_util_vertex
48{
49   float x, y, z;
50   float r, g, b, a;
51   float s, t;
52};
53
54
55
56/* Invalidate the readpixels cache to ensure we don't read stale data.
57 */
58static inline void
59st_invalidate_readpix_cache(struct st_context *st)
60{
61   if (unlikely(st->readpix_cache.src)) {
62      pipe_resource_reference(&st->readpix_cache.src, NULL);
63      pipe_resource_reference(&st->readpix_cache.cache, NULL);
64   }
65}
66
67
68#define Y_0_TOP 1
69#define Y_0_BOTTOM 2
70
71static inline GLuint
72st_fb_orientation(const struct gl_framebuffer *fb)
73{
74   if (fb && _mesa_is_winsys_fbo(fb)) {
75      /* Drawing into a window (on-screen buffer).
76       *
77       * Negate Y scale to flip image vertically.
78       * The NDC Y coords prior to viewport transformation are in the range
79       * [y=-1=bottom, y=1=top]
80       * Hardware window coords are in the range [y=0=top, y=H-1=bottom] where
81       * H is the window height.
82       * Use the viewport transformation to invert Y.
83       */
84      return Y_0_TOP;
85   }
86   else {
87      /* Drawing into user-created FBO (very likely a texture).
88       *
89       * For textures, T=0=Bottom, so by extension Y=0=Bottom for rendering.
90       */
91      return Y_0_BOTTOM;
92   }
93}
94
95
96static inline bool
97st_user_clip_planes_enabled(struct gl_context *ctx)
98{
99   return (ctx->API == API_OPENGL_COMPAT ||
100           ctx->API == API_OPENGLES) && /* only ES 1.x */
101          ctx->Transform.ClipPlanesEnabled;
102}
103
104
105/** clear-alloc a struct-sized object, with casting */
106#define ST_CALLOC_STRUCT(T)   (struct T *) calloc(1, sizeof(struct T))
107
108
109#ifdef __cplusplus
110}
111#endif
112
113
114#endif /* ST_UTIL */
115