text: /*
   * Mesa 3-D graphics library
   * Version:  6.1
   *
   * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included
   * in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
   * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  #include "glheader.h"
  #include "api_validate.h"
  #include "context.h"
  #include "imports.h"
  #include "mtypes.h"
  #include "state.h"
  
  
  GLboolean
  _mesa_validate_DrawElements(GLcontext *ctx,
  			    GLenum mode, GLsizei count, GLenum type,
  			    const GLvoid *indices)
  {
     ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx,  GL_FALSE);
  
     if (count <= 0) {
        if (count < 0)
  	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawElements(count)" );
        return GL_FALSE;
     }
  
     if (mode > GL_POLYGON) {
        _mesa_error(ctx, GL_INVALID_ENUM, "glDrawElements(mode)" );
        return GL_FALSE;
     }
  
     if (type != GL_UNSIGNED_INT &&
         type != GL_UNSIGNED_BYTE &&
         type != GL_UNSIGNED_SHORT)
     {
        _mesa_error(ctx, GL_INVALID_ENUM, "glDrawElements(type)" );
        return GL_FALSE;
     }
  
     if (ctx->NewState)
        _mesa_update_state(ctx);
  
     /* Always need vertex positions */
     if (!ctx->Array.Vertex.Enabled
         && !(ctx->VertexProgram._Enabled && ctx->Array.VertexAttrib[0].Enabled))
        return GL_FALSE;
  
     /* Vertex buffer object tests */
     if (ctx->Array.ElementArrayBufferObj->Name) {
        GLuint indexBytes;
  
        /* use indices in the buffer object */
        if (!ctx->Array.ElementArrayBufferObj->Data) {
           _mesa_warning(ctx, "DrawElements with empty vertex elements buffer!");
           return GL_FALSE;
        }
  
        /* make sure count doesn't go outside buffer bounds */
        if (type == GL_UNSIGNED_INT) {
           indexBytes = count * sizeof(GLuint);
        }
        else if (type == GL_UNSIGNED_BYTE) {
           indexBytes = count * sizeof(GLubyte);
        }
        else {
           ASSERT(type == GL_UNSIGNED_SHORT);
           indexBytes = count * sizeof(GLushort);
        }
  
        if ((GLubyte *) indices + indexBytes >
            ctx->Array.ElementArrayBufferObj->Data +
            ctx->Array.ElementArrayBufferObj->Size) {
           _mesa_warning(ctx, "glDrawElements index out of buffer bounds");
           return GL_FALSE;
        }
  
        /* Actual address is the sum of pointers.  Indices may be used below. */
        if (ctx->Const.CheckArrayBounds) {
           indices = (const GLvoid *)
              ADD_POINTERS(ctx->Array.ElementArrayBufferObj->Data,
                           (const GLubyte *) indices);
        }
     }
  
     if (ctx->Const.CheckArrayBounds) {
        /* find max array index */
        GLuint max = 0;
        GLint i;
        if (type == GL_UNSIGNED_INT) {
           for (i = 0; i < count; i++)
              if (((GLuint *) indices)[i] > max)
                 max = ((GLuint *) indices)[i];
        }
        else if (type == GL_UNSIGNED_SHORT) {
           for (i = 0; i < count; i++)
              if (((GLushort *) indices)[i] > max)
                 max = ((GLushort *) indices)[i];
        }
        else {
           ASSERT(type == GL_UNSIGNED_BYTE);
           for (i = 0; i < count; i++)
              if (((GLubyte *) indices)[i] > max)
                 max = ((GLubyte *) indices)[i];
        }
        if (max >= ctx->Array._MaxElement) {
           /* the max element is out of bounds of one or more enabled arrays */
           return GL_FALSE;
        }
     }
  
     return GL_TRUE;
  }
  
  
  GLboolean
  _mesa_validate_DrawRangeElements(GLcontext *ctx, GLenum mode,
  				 GLuint start, GLuint end,
  				 GLsizei count, GLenum type,
  				 const GLvoid *indices)
  {
     ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
  
     if (count <= 0) {
        if (count < 0)
  	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(count)" );
        return GL_FALSE;
     }
  
     if (mode > GL_POLYGON) {
        _mesa_error(ctx, GL_INVALID_ENUM, "glDrawRangeElements(mode)" );
        return GL_FALSE;
     }
  
     if (end < start) {
        _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(end<start)");
        return GL_FALSE;
     }
  
     if (type != GL_UNSIGNED_INT &&
         type != GL_UNSIGNED_BYTE &&
         type != GL_UNSIGNED_SHORT) {
        _mesa_error(ctx, GL_INVALID_ENUM, "glDrawRangeElements(type)" );
        return GL_FALSE;
     }
  
     if (ctx->NewState)
        _mesa_update_state(ctx);
  
     /* Always need vertex positions */
     if (!ctx->Array.Vertex.Enabled
         && !(ctx->VertexProgram._Enabled && ctx->Array.VertexAttrib[0].Enabled))
        return GL_FALSE;
  
     if (ctx->Const.CheckArrayBounds) {
        /* Find max array index.
         * We don't trust the user's start and end values.
         */
        GLuint max = 0;
        GLint i;
        if (type == GL_UNSIGNED_INT) {
           for (i = 0; i < count; i++)
              if (((GLuint *) indices)[i] > max)
                 max = ((GLuint *) indices)[i];
        }
        else if (type == GL_UNSIGNED_SHORT) {
           for (i = 0; i < count; i++)
              if (((GLushort *) indices)[i] > max)
                 max = ((GLushort *) indices)[i];
        }
        else {
           ASSERT(type == GL_UNSIGNED_BYTE);
           for (i = 0; i < count; i++)
              if (((GLubyte *) indices)[i] > max)
                 max = ((GLubyte *) indices)[i];
        }
        if (max >= ctx->Array._MaxElement) {
           /* the max element is out of bounds of one or more enabled arrays */
           return GL_FALSE;
        }
     }
  
     return GL_TRUE;
  }
  
  
  /**
   * Called from the tnl module to error check the function parameters and
   * verify that we really can draw something.
   */
  GLboolean
  _mesa_validate_DrawArrays(GLcontext *ctx,
  			  GLenum mode, GLint start, GLsizei count)
  {
     ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
  
     if (count < 0) {
        _mesa_error(ctx, GL_INVALID_VALUE, "glDrawArrays(count)" );
        return GL_FALSE;
     }
  
     if (mode > GL_POLYGON) {
        _mesa_error(ctx, GL_INVALID_ENUM, "glDrawArrays(mode)" );
        return GL_FALSE;
     }
  
     if (ctx->NewState)
        _mesa_update_state(ctx);
  
     /* Always need vertex positions */
     if (!ctx->Array.Vertex.Enabled && !ctx->Array.VertexAttrib[0].Enabled)
        return GL_FALSE;
  
     if (ctx->Const.CheckArrayBounds) {
        if (start + count > (GLint) ctx->Array._MaxElement)
           return GL_FALSE;
     }
  
     return GL_TRUE;
  }
  