src/mesa/main/formatquery.c

   1 /*
   2  * Copyright © 2012 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include "mtypes.h"
  25 #include "glformats.h"
  26 #include "macros.h"
  27 #include "mfeatures.h"
  28 #include "enums.h"
  29 #include "fbobject.h"
  30 #include "formatquery.h"
  31
  32 void GLAPIENTRY
  33 _mesa_GetInternalformativ(GLenum target, GLenum internalformat, GLenum pname,
  34                           GLsizei bufSize, GLint *params)
  35 {
  36    GLint buffer[16];
  37    GLsizei count = 0;
  38    GET_CURRENT_CONTEXT(ctx);
  39
  40    if (!ctx->Extensions.ARB_internalformat_query) {
  41       _mesa_error(ctx, GL_INVALID_OPERATION, "glGetInternalformativ");
  42       return;
  43    }
  44
  45    assert(ctx->Driver.QuerySamplesForFormat != NULL);
  46
  47    /* The ARB_internalformat_query spec says:
  48     *
  49     *     "If the <target> parameter to GetInternalformativ is not one of
  50     *     TEXTURE_2D_MULTISAMPLE, TEXTURE_2D_MULTISAMPLE_ARRAY or RENDERBUFFER
  51     *     then an INVALID_ENUM error is generated."
  52     */
  53    switch (target) {
  54    case GL_RENDERBUFFER:
  55       break;
  56
  57    case GL_TEXTURE_2D_MULTISAMPLE:
  58    case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
  59       /* Mesa does not currently support GL_ARB_texture_multisample, so these
  60        * enums are not valid on this implementation either.
  61        */
  62    default:
  63       _mesa_error(ctx, GL_INVALID_ENUM,
  64                   "glGetInternalformativ(target=%s)",
  65                   _mesa_lookup_enum_by_nr(target));
  66       return;
  67    }
  68
  69    /* The ARB_internalformat_query spec says:
  70     *
  71     *     "If the <internalformat> parameter to GetInternalformativ is not
  72     *     color-, depth- or stencil-renderable, then an INVALID_ENUM error is
  73     *     generated."
  74     */
  75    if (_mesa_base_fbo_format(ctx, internalformat) == 0) {
  76       _mesa_error(ctx, GL_INVALID_ENUM,
  77                   "glGetInternalformativ(internalformat=%s)",
  78                   _mesa_lookup_enum_by_nr(internalformat));
  79       return;
  80    }
  81
  82    /* The ARB_internalformat_query spec says:
  83     *
  84     *     "If the <bufSize> parameter to GetInternalformativ is negative, then
  85     *     an INVALID_VALUE error is generated."
  86     */
  87    if (bufSize < 0) {
  88       _mesa_error(ctx, GL_INVALID_VALUE,
  89                   "glGetInternalformativ(target=%s)",
  90                   _mesa_lookup_enum_by_nr(target));
  91       return;
  92    }
  93
  94    switch (pname) {
  95    case GL_SAMPLES:
  96       count = ctx->Driver.QuerySamplesForFormat(ctx, internalformat, buffer);
  97       break;
  98    case GL_NUM_SAMPLE_COUNTS: {
  99       /* The driver can return 0, and we should pass that along to the
 100        * application.  The ARB decided that ARB_internalformat_query should
 101        * behave as ARB_internalformat_query2 in this situation.
 102        *
 103        * The ARB_internalformat_query2 spec says:
 104        *
 105        *     "- NUM_SAMPLE_COUNTS: The number of sample counts that would be
 106        *        returned by querying SAMPLES is returned in <params>.
 107        *        * If <internalformat> is not color-renderable,
 108        *          depth-renderable, or stencil-renderable (as defined in
 109        *          section 4.4.4), or if <target> does not support multiple
 110        *          samples (ie other than TEXTURE_2D_MULTISAMPLE,
 111        *          TEXTURE_2D_MULTISAMPLE_ARRAY, or RENDERBUFFER), 0 is
 112        *          returned."
 113        */
 114       const size_t num_samples =
 115          ctx->Driver.QuerySamplesForFormat(ctx, internalformat, buffer);
 116
 117       /* QuerySamplesForFormat writes some stuff to buffer, so we have to
 118        * separately over-write it with the requested value.
 119        */
 120       buffer[0] = (GLint) num_samples;
 121       count = 1;
 122       break;
 123    }
 124    default:
 125       _mesa_error(ctx, GL_INVALID_ENUM,
 126                   "glGetInternalformativ(pname=%s)",
 127                   _mesa_lookup_enum_by_nr(pname));
 128       return;
 129    }
 130
 131    if (bufSize != 0 && params == NULL) {
 132       /* Emit a warning to aid application debugging, but go ahead and do the
 133        * memcpy (and probably crash) anyway.
 134        */
 135       _mesa_warning(ctx,
 136                     "glGetInternalformativ(bufSize = %d, but params = NULL)",
 137                     bufSize);
 138    }
 139
 140    /* Copy the data from the temporary buffer to the buffer supplied by the
 141     * application.  Clamp the size of the copy to the size supplied by the
 142     * application.
 143     */
 144    memcpy(params, buffer, MIN2(count, bufSize) * sizeof(GLint));
 145
 146    return;
 147 }