points.c revision 848b8605 
1/**
2 * \file points.c
3 * Point operations.
4 */
5
6/*
7 * Mesa 3-D graphics library
8 *
9 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a
12 * copy of this software and associated documentation files (the "Software"),
13 * to deal in the Software without restriction, including without limitation
14 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15 * and/or sell copies of the Software, and to permit persons to whom the
16 * Software is furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice shall be included
19 * in all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
22 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
24 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
25 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
26 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27 * OTHER DEALINGS IN THE SOFTWARE.
28 */
29
30
31#include "glheader.h"
32#include "context.h"
33#include "macros.h"
34#include "points.h"
35#include "mtypes.h"
36
37
38/**
39 * Set current point size.
40 * \param size  point diameter in pixels
41 * \sa glPointSize().
42 */
43void GLAPIENTRY
44_mesa_PointSize( GLfloat size )
45{
46   GET_CURRENT_CONTEXT(ctx);
47
48   if (size <= 0.0) {
49      _mesa_error( ctx, GL_INVALID_VALUE, "glPointSize" );
50      return;
51   }
52
53   if (ctx->Point.Size == size)
54      return;
55
56   FLUSH_VERTICES(ctx, _NEW_POINT);
57   ctx->Point.Size = size;
58
59   if (ctx->Driver.PointSize)
60      ctx->Driver.PointSize(ctx, size);
61}
62
63
64void GLAPIENTRY
65_mesa_PointParameteri( GLenum pname, GLint param )
66{
67   GLfloat p[3];
68   p[0] = (GLfloat) param;
69   p[1] = p[2] = 0.0F;
70   _mesa_PointParameterfv(pname, p);
71}
72
73
74void GLAPIENTRY
75_mesa_PointParameteriv( GLenum pname, const GLint *params )
76{
77   GLfloat p[3];
78   p[0] = (GLfloat) params[0];
79   if (pname == GL_DISTANCE_ATTENUATION_EXT) {
80      p[1] = (GLfloat) params[1];
81      p[2] = (GLfloat) params[2];
82   }
83   _mesa_PointParameterfv(pname, p);
84}
85
86
87void GLAPIENTRY
88_mesa_PointParameterf( GLenum pname, GLfloat param)
89{
90   GLfloat p[3];
91   p[0] = param;
92   p[1] = p[2] = 0.0F;
93   _mesa_PointParameterfv(pname, p);
94}
95
96
97void GLAPIENTRY
98_mesa_PointParameterfv( GLenum pname, const GLfloat *params)
99{
100   GET_CURRENT_CONTEXT(ctx);
101
102   /* Drivers that support point sprites must also support point parameters.
103    * If point parameters aren't supported, then this function shouldn't even
104    * exist.
105    */
106   ASSERT(!(ctx->Extensions.ARB_point_sprite
107            || ctx->Extensions.NV_point_sprite)
108          || ctx->Extensions.EXT_point_parameters);
109
110   if (!ctx->Extensions.EXT_point_parameters) {
111      _mesa_error(ctx, GL_INVALID_OPERATION,
112                  "unsupported function called (unsupported extension)");
113      return;
114   }
115
116   switch (pname) {
117      case GL_DISTANCE_ATTENUATION_EXT:
118         if (TEST_EQ_3V(ctx->Point.Params, params))
119            return;
120         FLUSH_VERTICES(ctx, _NEW_POINT);
121         COPY_3V(ctx->Point.Params, params);
122         ctx->Point._Attenuated = (ctx->Point.Params[0] != 1.0 ||
123                                   ctx->Point.Params[1] != 0.0 ||
124                                   ctx->Point.Params[2] != 0.0);
125         break;
126      case GL_POINT_SIZE_MIN_EXT:
127         if (params[0] < 0.0F) {
128            _mesa_error( ctx, GL_INVALID_VALUE,
129                         "glPointParameterf[v]{EXT,ARB}(param)" );
130            return;
131         }
132         if (ctx->Point.MinSize == params[0])
133            return;
134         FLUSH_VERTICES(ctx, _NEW_POINT);
135         ctx->Point.MinSize = params[0];
136         break;
137      case GL_POINT_SIZE_MAX_EXT:
138         if (params[0] < 0.0F) {
139            _mesa_error( ctx, GL_INVALID_VALUE,
140                         "glPointParameterf[v]{EXT,ARB}(param)" );
141            return;
142         }
143         if (ctx->Point.MaxSize == params[0])
144            return;
145         FLUSH_VERTICES(ctx, _NEW_POINT);
146         ctx->Point.MaxSize = params[0];
147         break;
148      case GL_POINT_FADE_THRESHOLD_SIZE_EXT:
149         if (params[0] < 0.0F) {
150            _mesa_error( ctx, GL_INVALID_VALUE,
151                         "glPointParameterf[v]{EXT,ARB}(param)" );
152            return;
153         }
154         if (ctx->Point.Threshold == params[0])
155            return;
156         FLUSH_VERTICES(ctx, _NEW_POINT);
157         ctx->Point.Threshold = params[0];
158         break;
159      case GL_POINT_SPRITE_R_MODE_NV:
160         /* This is one area where ARB_point_sprite and NV_point_sprite
161	  * differ.  In ARB_point_sprite the POINT_SPRITE_R_MODE is
162	  * always ZERO.  NV_point_sprite adds the S and R modes.
163	  */
164         if (_mesa_is_desktop_gl(ctx) && ctx->Extensions.NV_point_sprite) {
165            GLenum value = (GLenum) params[0];
166            if (value != GL_ZERO && value != GL_S && value != GL_R) {
167               _mesa_error(ctx, GL_INVALID_VALUE,
168                           "glPointParameterf[v]{EXT,ARB}(param)");
169               return;
170            }
171            if (ctx->Point.SpriteRMode == value)
172               return;
173            FLUSH_VERTICES(ctx, _NEW_POINT);
174            ctx->Point.SpriteRMode = value;
175         }
176         else {
177            _mesa_error(ctx, GL_INVALID_ENUM,
178                        "glPointParameterf[v]{EXT,ARB}(pname)");
179            return;
180         }
181         break;
182      case GL_POINT_SPRITE_COORD_ORIGIN:
183	 /* GL_POINT_SPRITE_COORD_ORIGIN was added to point sprites when the
184	  * extension was merged into OpenGL 2.0.
185	  */
186         if ((ctx->API == API_OPENGL_COMPAT && ctx->Version >= 20)
187             || ctx->API == API_OPENGL_CORE) {
188            GLenum value = (GLenum) params[0];
189            if (value != GL_LOWER_LEFT && value != GL_UPPER_LEFT) {
190               _mesa_error(ctx, GL_INVALID_VALUE,
191                           "glPointParameterf[v]{EXT,ARB}(param)");
192               return;
193            }
194            if (ctx->Point.SpriteOrigin == value)
195               return;
196            FLUSH_VERTICES(ctx, _NEW_POINT);
197            ctx->Point.SpriteOrigin = value;
198         }
199         else {
200            _mesa_error(ctx, GL_INVALID_ENUM,
201                        "glPointParameterf[v]{EXT,ARB}(pname)");
202            return;
203         }
204         break;
205      default:
206         _mesa_error( ctx, GL_INVALID_ENUM,
207                      "glPointParameterf[v]{EXT,ARB}(pname)" );
208         return;
209   }
210
211   if (ctx->Driver.PointParameterfv)
212      (*ctx->Driver.PointParameterfv)(ctx, pname, params);
213}
214
215
216
217/**
218 * Initialize the context point state.
219 *
220 * \param ctx GL context.
221 *
222 * Initializes __struct gl_contextRec::Point and point related constants in
223 * __struct gl_contextRec::Const.
224 */
225void
226_mesa_init_point(struct gl_context *ctx)
227{
228   GLuint i;
229
230   ctx->Point.SmoothFlag = GL_FALSE;
231   ctx->Point.Size = 1.0;
232   ctx->Point.Params[0] = 1.0;
233   ctx->Point.Params[1] = 0.0;
234   ctx->Point.Params[2] = 0.0;
235   ctx->Point._Attenuated = GL_FALSE;
236   ctx->Point.MinSize = 0.0;
237   ctx->Point.MaxSize
238      = MAX2(ctx->Const.MaxPointSize, ctx->Const.MaxPointSizeAA);
239   ctx->Point.Threshold = 1.0;
240
241   /* Page 403 (page 423 of the PDF) of the OpenGL 3.0 spec says:
242    *
243    *     "Non-sprite points (section 3.4) - Enable/Disable targets
244    *     POINT_SMOOTH and POINT_SPRITE, and all associated state. Point
245    *     rasterization is always performed as though POINT_SPRITE were
246    *     enabled."
247    *
248    * In a core context, the state will default to true, and the setters and
249    * getters are disabled.
250    */
251   ctx->Point.PointSprite = (ctx->API == API_OPENGL_CORE ||
252                             ctx->API == API_OPENGLES2);
253
254   ctx->Point.SpriteRMode = GL_ZERO; /* GL_NV_point_sprite (only!) */
255   ctx->Point.SpriteOrigin = GL_UPPER_LEFT; /* GL_ARB_point_sprite */
256   for (i = 0; i < Elements(ctx->Point.CoordReplace); i++) {
257      ctx->Point.CoordReplace[i] = GL_FALSE; /* GL_ARB/NV_point_sprite */
258   }
259}
260