src/mesa/main/multisample.c

   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  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 #include "main/glheader.h"
  28 #include "main/context.h"
  29 #include "main/macros.h"
  30 #include "main/multisample.h"
  31 #include "main/mtypes.h"
  32 #include "main/fbobject.h"
  33 #include "main/glformats.h"
  34 #include "main/state.h"
  35
  36
  37 /**
  38  * Called via glSampleCoverageARB
  39  */
  40 void GLAPIENTRY
  41 _mesa_SampleCoverage(GLclampf value, GLboolean invert)
  42 {
  43    GET_CURRENT_CONTEXT(ctx);
  44
  45    FLUSH_VERTICES(ctx, 0);
  46
  47    ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0);
  48    ctx->Multisample.SampleCoverageInvert = invert;
  49    ctx->NewState |= _NEW_MULTISAMPLE;
  50 }
  51
  52
  53 /**
  54  * Initialize the context's multisample state.
  55  * \param ctx  the GL context.
  56  */
  57 void
  58 _mesa_init_multisample(struct gl_context *ctx)
  59 {
  60    ctx->Multisample.Enabled = GL_TRUE;
  61    ctx->Multisample.SampleAlphaToCoverage = GL_FALSE;
  62    ctx->Multisample.SampleAlphaToOne = GL_FALSE;
  63    ctx->Multisample.SampleCoverage = GL_FALSE;
  64    ctx->Multisample.SampleCoverageValue = 1.0;
  65    ctx->Multisample.SampleCoverageInvert = GL_FALSE;
  66
  67    /* ARB_texture_multisample / GL3.2 additions */
  68    ctx->Multisample.SampleMask = GL_FALSE;
  69    ctx->Multisample.SampleMaskValue = ~(GLbitfield)0;
  70 }
  71
  72
  73 void GLAPIENTRY
  74 _mesa_GetMultisamplefv(GLenum pname, GLuint index, GLfloat * val)
  75 {
  76    GET_CURRENT_CONTEXT(ctx);
  77
  78    if (ctx->NewState & _NEW_BUFFERS) {
  79       _mesa_update_state(ctx);
  80    }
  81
  82    switch (pname) {
  83    case GL_SAMPLE_POSITION: {
  84       if (index >= ctx->DrawBuffer->Visual.samples) {
  85          _mesa_error( ctx, GL_INVALID_VALUE, "glGetMultisamplefv(index)" );
  86          return;
  87       }
  88
  89       ctx->Driver.GetSamplePosition(ctx, ctx->DrawBuffer, index, val);
  90
  91       /* winsys FBOs are upside down */
  92       if (_mesa_is_winsys_fbo(ctx->DrawBuffer))
  93          val[1] = 1 - val[1];
  94
  95       return;
  96    }
  97
  98    default:
  99       _mesa_error( ctx, GL_INVALID_ENUM, "glGetMultisamplefv(pname)" );
 100       return;
 101    }
 102 }
 103
 104 void GLAPIENTRY
 105 _mesa_SampleMaski(GLuint index, GLbitfield mask)
 106 {
 107    GET_CURRENT_CONTEXT(ctx);
 108
 109    if (!ctx->Extensions.ARB_texture_multisample) {
 110       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleMaski");
 111       return;
 112    }
 113
 114    if (index != 0) {
 115       _mesa_error(ctx, GL_INVALID_VALUE, "glSampleMaski(index)");
 116       return;
 117    }
 118
 119    FLUSH_VERTICES(ctx, _NEW_MULTISAMPLE);
 120    ctx->Multisample.SampleMaskValue = mask;
 121 }
 122
 123
 124 /* Helper for checking a requested sample count against the limit
 125  * for a particular (target, internalFormat) pair. The limit imposed,
 126  * and the error generated, both depend on which extensions are supported.
 127  *
 128  * Returns a GL error enum, or GL_NO_ERROR if the requested sample count is
 129  * acceptable.
 130  */
 131 GLenum
 132 _mesa_check_sample_count(struct gl_context *ctx, GLenum target,
 133                          GLenum internalFormat, GLsizei samples)
 134 {
 135    /* If ARB_internalformat_query is supported, then treat its highest returned sample
 136     * count as the absolute maximum for this format; it is allowed to exceed MAX_SAMPLES.
 137     *
 138     * From the ARB_internalformat_query spec:
 139     *
 140     * "If <samples is greater than the maximum number of samples supported
 141     * for <internalformat> then the error INVALID_OPERATION is generated."
 142     */
 143    if (ctx->Extensions.ARB_internalformat_query) {
 144       GLint buffer[16];
 145       int count = ctx->Driver.QuerySamplesForFormat(ctx, target, internalFormat, buffer);
 146       int limit = count ? buffer[0] : -1;
 147
 148       return samples > limit ? GL_INVALID_OPERATION : GL_NO_ERROR;
 149    }
 150
 151    /* If ARB_texture_multisample is supported, we have separate limits,
 152     * which may be lower than MAX_SAMPLES:
 153     *
 154     * From the ARB_texture_multisample spec, when describing the operation
 155     * of RenderbufferStorageMultisample:
 156     *
 157     * "If <internalformat> is a signed or unsigned integer format and
 158     * <samples> is greater than the value of MAX_INTEGER_SAMPLES, then the
 159     * error INVALID_OPERATION is generated"
 160     *
 161     * And when describing the operation of TexImage*Multisample:
 162     *
 163     * "The error INVALID_OPERATION may be generated if any of the following are true:
 164     *
 165     * * <internalformat> is a depth/stencil-renderable format and <samples>
 166     *   is greater than the value of MAX_DEPTH_TEXTURE_SAMPLES
 167     * * <internalformat> is a color-renderable format and <samples> is
 168     *   grater than the value of MAX_COLOR_TEXTURE_SAMPLES
 169     * * <internalformat> is a signed or unsigned integer format and
 170     *   <samples> is greater than the value of MAX_INTEGER_SAMPLES
 171     */
 172
 173    if (ctx->Extensions.ARB_texture_multisample) {
 174       if (_mesa_is_enum_format_integer(internalFormat))
 175          return samples > ctx->Const.MaxIntegerSamples ? GL_INVALID_OPERATION : GL_NO_ERROR;
 176
 177       if (target == GL_TEXTURE_2D_MULTISAMPLE ||
 178           target == GL_TEXTURE_2D_MULTISAMPLE_ARRAY) {
 179
 180          if (_mesa_is_depth_or_stencil_format(internalFormat))
 181             return samples > ctx->Const.MaxDepthTextureSamples
 182                ? GL_INVALID_OPERATION : GL_NO_ERROR;
 183          else
 184             return samples > ctx->Const.MaxColorTextureSamples
 185                ? GL_INVALID_OPERATION : GL_NO_ERROR;
 186       }
 187    }
 188
 189    /* No more specific limit is available, so just use MAX_SAMPLES:
 190     *
 191     * On p205 of the GL3.1 spec:
 192     *
 193     * "... or if samples is greater than MAX_SAMPLES, then the error
 194     * INVALID_VALUE is generated"
 195     */
 196    return samples > ctx->Const.MaxSamples ? GL_INVALID_VALUE : GL_NO_ERROR;
 197 }