api_validate.c revision 8d482227915552c414e13743652e6794c4313ae2 
1/*
2 * Mesa 3-D graphics library
3 * Version:  7.1
4 *
5 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25#include "glheader.h"
26#include "api_validate.h"
27#include "context.h"
28#include "imports.h"
29#include "mtypes.h"
30#include "state.h"
31
32
33
34/**
35 * \return  number of bytes in array [count] of type.
36 */
37static GLsizei
38index_bytes(GLenum type, GLsizei count)
39{
40   if (type == GL_UNSIGNED_INT) {
41      return count * sizeof(GLuint);
42   }
43   else if (type == GL_UNSIGNED_BYTE) {
44      return count * sizeof(GLubyte);
45   }
46   else {
47      ASSERT(type == GL_UNSIGNED_SHORT);
48      return count * sizeof(GLushort);
49   }
50}
51
52
53/**
54 * Find the max index in the given element/index buffer
55 */
56static GLuint
57max_buffer_index(GLcontext *ctx, GLuint count, GLenum type,
58                 const void *indices,
59                 struct gl_buffer_object *elementBuf)
60{
61   const GLubyte *map = NULL;
62   GLuint max = 0;
63   GLuint i;
64
65   if (elementBuf->Name) {
66      /* elements are in a user-defined buffer object.  need to map it */
67      map = ctx->Driver.MapBuffer(ctx, GL_ELEMENT_ARRAY_BUFFER,
68                                  GL_READ_ONLY, elementBuf);
69      /* Actual address is the sum of pointers */
70      indices = (const GLvoid *) ADD_POINTERS(map, (const GLubyte *) indices);
71   }
72
73   if (type == GL_UNSIGNED_INT) {
74      for (i = 0; i < count; i++)
75         if (((GLuint *) indices)[i] > max)
76            max = ((GLuint *) indices)[i];
77   }
78   else if (type == GL_UNSIGNED_SHORT) {
79      for (i = 0; i < count; i++)
80         if (((GLushort *) indices)[i] > max)
81            max = ((GLushort *) indices)[i];
82   }
83   else {
84      ASSERT(type == GL_UNSIGNED_BYTE);
85      for (i = 0; i < count; i++)
86         if (((GLubyte *) indices)[i] > max)
87            max = ((GLubyte *) indices)[i];
88   }
89
90   if (map) {
91      ctx->Driver.UnmapBuffer(ctx, GL_ELEMENT_ARRAY_BUFFER_ARB, elementBuf);
92   }
93
94   return max;
95}
96
97
98/**
99 * Check if OK to render by examining framebuffer status and vertex arrays.
100 */
101static GLboolean
102check_valid_to_render(GLcontext *ctx, char *function)
103{
104   if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
105      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
106                  "glDraw%s(incomplete framebuffer)", function);
107      return GL_FALSE;
108   }
109
110#if FEATURE_es2_glsl
111   /* For ES2, we can draw if any vertex array is enabled (and we should
112    * always have a vertex program/shader).
113    */
114   if (ctx->Array.ArrayObj->_Enabled == 0x0 || !ctx->VertexProgram._Current)
115      return GL_FALSE;
116#else
117   /* For regular OpenGL, only draw if we have vertex positions (regardless
118    * of whether or not we have a vertex program/shader).
119    */
120   if (!ctx->Array.ArrayObj->Vertex.Enabled &&
121       !ctx->Array.ArrayObj->VertexAttrib[0].Enabled)
122      return GL_FALSE;
123#endif
124
125   return GL_TRUE;
126}
127
128
129/**
130 * Error checking for glDrawElements().  Includes parameter checking
131 * and VBO bounds checking.
132 * \return GL_TRUE if OK to render, GL_FALSE if error found
133 */
134GLboolean
135_mesa_validate_DrawElements(GLcontext *ctx,
136			    GLenum mode, GLsizei count, GLenum type,
137			    const GLvoid *indices)
138{
139   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx,  GL_FALSE);
140
141   if (count <= 0) {
142      if (count < 0)
143	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawElements(count)" );
144      return GL_FALSE;
145   }
146
147   if (mode > GL_POLYGON) {
148      _mesa_error(ctx, GL_INVALID_ENUM, "glDrawElements(mode)" );
149      return GL_FALSE;
150   }
151
152   if (type != GL_UNSIGNED_INT &&
153       type != GL_UNSIGNED_BYTE &&
154       type != GL_UNSIGNED_SHORT)
155   {
156      _mesa_error(ctx, GL_INVALID_ENUM, "glDrawElements(type)" );
157      return GL_FALSE;
158   }
159
160   if (ctx->NewState)
161      _mesa_update_state(ctx);
162
163   if (!check_valid_to_render(ctx, "Elements"))
164      return GL_FALSE;
165
166   /* Vertex buffer object tests */
167   if (ctx->Array.ElementArrayBufferObj->Name) {
168      /* use indices in the buffer object */
169      /* make sure count doesn't go outside buffer bounds */
170      if (index_bytes(type, count) > ctx->Array.ElementArrayBufferObj->Size) {
171         _mesa_warning(ctx, "glDrawElements index out of buffer bounds");
172         return GL_FALSE;
173      }
174   }
175   else {
176      /* not using a VBO */
177      if (!indices)
178         return GL_FALSE;
179   }
180
181   if (ctx->Const.CheckArrayBounds) {
182      /* find max array index */
183      GLuint max = max_buffer_index(ctx, count, type, indices,
184                                    ctx->Array.ElementArrayBufferObj);
185      if (max >= ctx->Array.ArrayObj->_MaxElement) {
186         /* the max element is out of bounds of one or more enabled arrays */
187         _mesa_warning(ctx, "glDrawElements() index=%u is "
188                       "out of bounds (max=%u)", max, ctx->Array.ArrayObj->_MaxElement);
189         return GL_FALSE;
190      }
191   }
192
193   return GL_TRUE;
194}
195
196
197/**
198 * Error checking for glDrawRangeElements().  Includes parameter checking
199 * and VBO bounds checking.
200 * \return GL_TRUE if OK to render, GL_FALSE if error found
201 */
202GLboolean
203_mesa_validate_DrawRangeElements(GLcontext *ctx, GLenum mode,
204				 GLuint start, GLuint end,
205				 GLsizei count, GLenum type,
206				 const GLvoid *indices)
207{
208   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
209
210   if (count <= 0) {
211      if (count < 0)
212	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(count)" );
213      return GL_FALSE;
214   }
215
216   if (mode > GL_POLYGON) {
217      _mesa_error(ctx, GL_INVALID_ENUM, "glDrawRangeElements(mode)" );
218      return GL_FALSE;
219   }
220
221   if (end < start) {
222      _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(end<start)");
223      return GL_FALSE;
224   }
225
226   if (type != GL_UNSIGNED_INT &&
227       type != GL_UNSIGNED_BYTE &&
228       type != GL_UNSIGNED_SHORT) {
229      _mesa_error(ctx, GL_INVALID_ENUM, "glDrawRangeElements(type)" );
230      return GL_FALSE;
231   }
232
233   if (ctx->NewState)
234      _mesa_update_state(ctx);
235
236   if (!check_valid_to_render(ctx, "RangeElements"))
237      return GL_FALSE;
238
239   /* Vertex buffer object tests */
240   if (ctx->Array.ElementArrayBufferObj->Name) {
241      /* use indices in the buffer object */
242      /* make sure count doesn't go outside buffer bounds */
243      if (index_bytes(type, count) > ctx->Array.ElementArrayBufferObj->Size) {
244         _mesa_warning(ctx, "glDrawRangeElements index out of buffer bounds");
245         return GL_FALSE;
246      }
247   }
248   else {
249      /* not using a VBO */
250      if (!indices)
251         return GL_FALSE;
252   }
253
254   if (ctx->Const.CheckArrayBounds) {
255      GLuint max = max_buffer_index(ctx, count, type, indices,
256                                    ctx->Array.ElementArrayBufferObj);
257      if (max >= ctx->Array.ArrayObj->_MaxElement) {
258         /* the max element is out of bounds of one or more enabled arrays */
259         return GL_FALSE;
260      }
261   }
262
263   return GL_TRUE;
264}
265
266
267/**
268 * Called from the tnl module to error check the function parameters and
269 * verify that we really can draw something.
270 * \return GL_TRUE if OK to render, GL_FALSE if error found
271 */
272GLboolean
273_mesa_validate_DrawArrays(GLcontext *ctx,
274			  GLenum mode, GLint start, GLsizei count)
275{
276   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
277
278   if (count <= 0) {
279      if (count < 0)
280         _mesa_error(ctx, GL_INVALID_VALUE, "glDrawArrays(count)" );
281      return GL_FALSE;
282   }
283
284   if (mode > GL_POLYGON) {
285      _mesa_error(ctx, GL_INVALID_ENUM, "glDrawArrays(mode)" );
286      return GL_FALSE;
287   }
288
289   if (ctx->NewState)
290      _mesa_update_state(ctx);
291
292   if (!check_valid_to_render(ctx, "Arrays"))
293      return GL_FALSE;
294
295   if (ctx->Const.CheckArrayBounds) {
296      if (start + count > (GLint) ctx->Array.ArrayObj->_MaxElement)
297         return GL_FALSE;
298   }
299
300   return GL_TRUE;
301}
302