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  * 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
  26 #include "main/glheader.h"
  27 #include "main/context.h"
  28 #include "main/macros.h"
  29 #include "main/multisample.h"
  30 #include "main/mtypes.h"
  31 #include "main/fbobject.h"
  32 #include "main/glformats.h"
  33
  34
  35 /**
  36  * Called via glSampleCoverageARB
  37  */
  38 void GLAPIENTRY
  39 _mesa_SampleCoverage(GLclampf value, GLboolean invert)
  40 {
  41    GET_CURRENT_CONTEXT(ctx);
  42
  43    FLUSH_VERTICES(ctx, 0);
  44
  45    ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0);
  46    ctx->Multisample.SampleCoverageInvert = invert;
  47    ctx->NewState |= _NEW_MULTISAMPLE;
  48 }
  49
  50
  51 /**
  52  * Initialize the context's multisample state.
  53  * \param ctx  the GL context.
  54  */
  55 void
  56 _mesa_init_multisample(struct gl_context *ctx)
  57 {
  58    ctx->Multisample.Enabled = GL_TRUE;
  59    ctx->Multisample.SampleAlphaToCoverage = GL_FALSE;
  60    ctx->Multisample.SampleAlphaToOne = GL_FALSE;
  61    ctx->Multisample.SampleCoverage = GL_FALSE;
  62    ctx->Multisample.SampleCoverageValue = 1.0;
  63    ctx->Multisample.SampleCoverageInvert = GL_FALSE;
  64
  65    /* ARB_texture_multisample / GL3.2 additions */
  66    ctx->Multisample.SampleMask = GL_FALSE;
  67    ctx->Multisample.SampleMaskValue = ~(GLbitfield)0;
  68 }
  69
  70
  71 void GLAPIENTRY
  72 _mesa_GetMultisamplefv(GLenum pname, GLuint index, GLfloat * val)
  73 {
  74    GET_CURRENT_CONTEXT(ctx);
  75
  76    switch (pname) {
  77    case GL_SAMPLE_POSITION: {
  78       if (index >= ctx->DrawBuffer->Visual.samples) {
  79          _mesa_error( ctx, GL_INVALID_VALUE, "glGetMultisamplefv(index)" );
  80          return;
  81       }
  82
  83       ctx->Driver.GetSamplePosition(ctx, ctx->DrawBuffer, index, val);
  84
  85       /* winsys FBOs are upside down */
  86       if (_mesa_is_winsys_fbo(ctx->DrawBuffer))
  87          val[1] = 1 - val[1];
  88
  89       return;
  90    }
  91
  92    default:
  93       _mesa_error( ctx, GL_INVALID_ENUM, "glGetMultisamplefv(pname)" );
  94       return;
  95    }
  96 }
  97
  98 void GLAPIENTRY
  99 _mesa_SampleMaski(GLuint index, GLbitfield mask)
 100 {
 101    GET_CURRENT_CONTEXT(ctx);
 102
 103    if (!ctx->Extensions.ARB_texture_multisample) {
 104       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleMaski");
 105       return;
 106    }
 107
 108    if (index != 0) {
 109       _mesa_error(ctx, GL_INVALID_VALUE, "glSampleMaski(index)");
 110       return;
 111    }
 112
 113    FLUSH_VERTICES(ctx, _NEW_MULTISAMPLE);
 114    ctx->Multisample.SampleMaskValue = mask;
 115 }
 116
 117
 118 /* Helper for checking a requested sample count against the limit
 119  * for a particular (target, internalFormat) pair. The limit imposed,
 120  * and the error generated, both depend on which extensions are supported.
 121  *
 122  * Returns a GL error enum, or GL_NO_ERROR if the requested sample count is
 123  * acceptable.
 124  */
 125 GLenum
 126 _mesa_check_sample_count(struct gl_context *ctx, GLenum target,
 127                          GLenum internalFormat, GLsizei samples)
 128 {
 129    /* If ARB_internalformat_query is supported, then treat its highest returned sample
 130     * count as the absolute maximum for this format; it is allowed to exceed MAX_SAMPLES.
 131     *
 132     * From the ARB_internalformat_query spec:
 133     *
 134     * "If <samples is greater than the maximum number of samples supported
 135     * for <internalformat> then the error INVALID_OPERATION is generated."
 136     */
 137    if (ctx->Extensions.ARB_internalformat_query) {
 138       GLint buffer[16];
 139       int count = ctx->Driver.QuerySamplesForFormat(ctx, target, internalFormat, buffer);
 140       int limit = count ? buffer[0] : -1;
 141
 142       return samples > limit ? GL_INVALID_OPERATION : GL_NO_ERROR;
 143    }
 144
 145    /* If ARB_texture_multisample is supported, we have separate limits for
 146     * integer formats.
 147     *
 148     * From the ARB_texture_multisample spec:
 149     *
 150     * "If <internalformat> is a signed or unsigned integer format and
 151     * <samples> is greater than the value of MAX_INTEGER_SAMPLES, then the
 152     * error INVALID_OPERATION is generated"
 153     */
 154
 155    if (ctx->Extensions.ARB_texture_multisample) {
 156       if (_mesa_is_enum_format_integer(internalFormat))
 157          return samples > ctx->Const.MaxIntegerSamples ? GL_INVALID_OPERATION : GL_NO_ERROR;
 158    }
 159
 160    /* No more specific limit is available, so just use MAX_SAMPLES:
 161     *
 162     * On p205 of the GL3.1 spec:
 163     *
 164     * "... or if samples is greater than MAX_SAMPLES, then the error
 165     * INVALID_VALUE is generated"
 166     */
 167    return samples > ctx->Const.MaxSamples ? GL_INVALID_VALUE : GL_NO_ERROR;
 168 }