1 /**************************************************************************
2 *
3 * Copyright 2002 VMware, Inc.
4 * Copyright 2011 Dave Airlie (ARB_vertex_type_2_10_10_10_rev support)
5 * Copyright 2020 Advanced Micro Devices, Inc.
6 * All Rights Reserved.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the
10 * "Software"), to deal in the Software without restriction, including
11 * without limitation the rights to use, copy, modify, merge, publish,
12 * distribute, sub license, and/or sell copies of the Software, and to
13 * permit persons to whom the Software is furnished to do so, subject to
14 * the following conditions:
15 *
16 * The above copyright notice and this permission notice (including the
17 * next paragraph) shall be included in all copies or substantial portions
18 * of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
21 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
23 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
24 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
25 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
26 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
27 *
28 **************************************************************************/
29
30 #ifndef VBO_UTIL_H
31 #define VBO_UTIL_H
32
conv_ui10_to_norm_float(unsigned ui10)33 static inline float conv_ui10_to_norm_float(unsigned ui10)
34 {
35 return ui10 / 1023.0f;
36 }
37
conv_ui2_to_norm_float(unsigned ui2)38 static inline float conv_ui2_to_norm_float(unsigned ui2)
39 {
40 return ui2 / 3.0f;
41 }
42
43 struct attr_bits_10 {signed int x:10;};
44 struct attr_bits_2 {signed int x:2;};
45
conv_i10_to_i(int i10)46 static inline float conv_i10_to_i(int i10)
47 {
48 struct attr_bits_10 val;
49 val.x = i10;
50 return (float)val.x;
51 }
52
conv_i2_to_i(int i2)53 static inline float conv_i2_to_i(int i2)
54 {
55 struct attr_bits_2 val;
56 val.x = i2;
57 return (float)val.x;
58 }
59
conv_i10_to_norm_float(const struct gl_context * ctx,int i10)60 static inline float conv_i10_to_norm_float(const struct gl_context *ctx, int i10)
61 {
62 struct attr_bits_10 val;
63 val.x = i10;
64
65 /* Traditionally, OpenGL has had two equations for converting from
66 * normalized fixed-point data to floating-point data. In the OpenGL 3.2
67 * specification, these are equations 2.2 and 2.3, respectively:
68 *
69 * f = (2c + 1)/(2^b - 1). (2.2)
70 *
71 * Comments below this equation state: "In general, this representation is
72 * used for signed normalized fixed-point parameters in GL commands, such
73 * as vertex attribute values." Which is what we're doing here.
74 *
75 * f = max{c/(2^(b-1) - 1), -1.0} (2.3)
76 *
77 * Comments below this equation state: "In general, this representation is
78 * used for signed normalized fixed-point texture or floating point values."
79 *
80 * OpenGL 4.2+ and ES 3.0 remedy this and state that equation 2.3 (above)
81 * is used in every case. They remove equation 2.2 completely.
82 */
83 if (_mesa_is_gles3(ctx) ||
84 (_mesa_is_desktop_gl(ctx) && ctx->Version >= 42)) {
85 /* Equation 2.3 above. */
86 float f = ((float) val.x) / 511.0F;
87 return MAX2(f, -1.0f);
88 } else {
89 /* Equation 2.2 above. */
90 return (2.0F * (float)val.x + 1.0F) * (1.0F / 1023.0F);
91 }
92 }
93
conv_i2_to_norm_float(const struct gl_context * ctx,int i2)94 static inline float conv_i2_to_norm_float(const struct gl_context *ctx, int i2)
95 {
96 struct attr_bits_2 val;
97 val.x = i2;
98
99 if (_mesa_is_gles3(ctx) ||
100 (_mesa_is_desktop_gl(ctx) && ctx->Version >= 42)) {
101 /* Equation 2.3 above. */
102 float f = (float) val.x;
103 return MAX2(f, -1.0f);
104 } else {
105 /* Equation 2.2 above. */
106 return (2.0F * (float)val.x + 1.0F) * (1.0F / 3.0F);
107 }
108 }
109
110 #define ERROR_IF_NOT_PACKED_TYPE(ctx, type, func) \
111 if (type != GL_INT_2_10_10_10_REV && type != GL_UNSIGNED_INT_2_10_10_10_REV) { \
112 _mesa_error(ctx, GL_INVALID_ENUM, "%s(type)", func); \
113 return; \
114 }
115
116 /* Extended version of ERROR_IF_NOT_PACKED_TYPE which also
117 * accepts GL_UNSIGNED_INT_10F_11F_11F_REV.
118 *
119 * Only used for VertexAttribP[123]ui[v]; VertexAttribP4* cannot use this type,
120 * and neither can legacy vertex attribs.
121 */
122 #define ERROR_IF_NOT_PACKED_TYPE_EXT(ctx, type, func) \
123 if (type != GL_INT_2_10_10_10_REV && type != GL_UNSIGNED_INT_2_10_10_10_REV && \
124 type != GL_UNSIGNED_INT_10F_11F_11F_REV) { \
125 _mesa_error(ctx, GL_INVALID_ENUM, "%s(type)", func); \
126 return; \
127 }
128
129 #endif
130