src/mesa/main/multisample.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * 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 #include "main/state.h"
  34
  35
  36 /**
  37  * Called via glSampleCoverageARB
  38  */
  39 void GLAPIENTRY
  40 _mesa_SampleCoverage(GLclampf value, GLboolean invert)
  41 {
  42    GET_CURRENT_CONTEXT(ctx);
  43
  44    FLUSH_VERTICES(ctx, 0);
  45
  46    ctx->Multisample.SampleCoverageValue = CLAMP(value, 0.0f, 1.0f);
  47    ctx->Multisample.SampleCoverageInvert = invert;
  48    ctx->NewState |= _NEW_MULTISAMPLE;
  49 }
  50
  51
  52 /**
  53  * Initialize the context's multisample state.
  54  * \param ctx  the GL context.
  55  */
  56 void
  57 _mesa_init_multisample(struct gl_context *ctx)
  58 {
  59    ctx->Multisample.Enabled = GL_TRUE;
  60    ctx->Multisample.SampleAlphaToCoverage = GL_FALSE;
  61    ctx->Multisample.SampleAlphaToOne = GL_FALSE;
  62    ctx->Multisample.SampleCoverage = GL_FALSE;
  63    ctx->Multisample.SampleCoverageValue = 1.0;
  64    ctx->Multisample.SampleCoverageInvert = GL_FALSE;
  65
  66    /* ARB_texture_multisample / GL3.2 additions */
  67    ctx->Multisample.SampleMask = GL_FALSE;
  68    ctx->Multisample.SampleMaskValue = ~(GLbitfield)0;
  69 }
  70
  71
  72 void GLAPIENTRY
  73 _mesa_GetMultisamplefv(GLenum pname, GLuint index, GLfloat * val)
  74 {
  75    GET_CURRENT_CONTEXT(ctx);
  76
  77    if (ctx->NewState & _NEW_BUFFERS) {
  78       _mesa_update_state(ctx);
  79    }
  80
  81    switch (pname) {
  82    case GL_SAMPLE_POSITION: {
  83       if ((int) index >= ctx->DrawBuffer->Visual.samples) {
  84          _mesa_error( ctx, GL_INVALID_VALUE, "glGetMultisamplefv(index)" );
  85          return;
  86       }
  87
  88       ctx->Driver.GetSamplePosition(ctx, ctx->DrawBuffer, index, val);
  89
  90       /* winsys FBOs are upside down */
  91       if (_mesa_is_winsys_fbo(ctx->DrawBuffer))
  92          val[1] = 1.0f - val[1];
  93
  94       return;
  95    }
  96
  97    default:
  98       _mesa_error( ctx, GL_INVALID_ENUM, "glGetMultisamplefv(pname)" );
  99       return;
 100    }
 101 }
 102
 103 void GLAPIENTRY
 104 _mesa_SampleMaski(GLuint index, GLbitfield mask)
 105 {
 106    GET_CURRENT_CONTEXT(ctx);
 107
 108    if (!ctx->Extensions.ARB_texture_multisample) {
 109       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleMaski");
 110       return;
 111    }
 112
 113    if (index != 0) {
 114       _mesa_error(ctx, GL_INVALID_VALUE, "glSampleMaski(index)");
 115       return;
 116    }
 117
 118    FLUSH_VERTICES(ctx, _NEW_MULTISAMPLE);
 119    ctx->Multisample.SampleMaskValue = mask;
 120 }
 121
 122 /**
 123  * Called via glMinSampleShadingARB
 124  */
 125 void GLAPIENTRY
 126 _mesa_MinSampleShading(GLclampf value)
 127 {
 128    GET_CURRENT_CONTEXT(ctx);
 129
 130    if (!ctx->Extensions.ARB_sample_shading || !_mesa_is_desktop_gl(ctx)) {
 131       _mesa_error(ctx, GL_INVALID_OPERATION, "glMinSampleShading");
 132       return;
 133    }
 134
 135    FLUSH_VERTICES(ctx, 0);
 136
 137    ctx->Multisample.MinSampleShadingValue = CLAMP(value, 0.0f, 1.0f);
 138    ctx->NewState |= _NEW_MULTISAMPLE;
 139 }
 140
 141 /**
 142  * Helper for checking a requested sample count against the limit
 143  * for a particular (target, internalFormat) pair. The limit imposed,
 144  * and the error generated, both depend on which extensions are supported.
 145  *
 146  * Returns a GL error enum, or GL_NO_ERROR if the requested sample count is
 147  * acceptable.
 148  */
 149 GLenum
 150 _mesa_check_sample_count(struct gl_context *ctx, GLenum target,
 151                          GLenum internalFormat, GLsizei samples)
 152 {
 153    /* Section 4.4 (Framebuffer objects), page 198 of the OpenGL ES 3.0.0
 154     * specification says:
 155     *
 156     *     "If internalformat is a signed or unsigned integer format and samples
 157     *     is greater than zero, then the error INVALID_OPERATION is generated."
 158     *
 159     * This restriction is relaxed for OpenGL ES 3.1.
 160     */
 161    if ((ctx->API == API_OPENGLES2 && ctx->Version == 30) &&
 162        _mesa_is_enum_format_integer(internalFormat)
 163        && samples > 0) {
 164       return GL_INVALID_OPERATION;
 165    }
 166
 167    /* If ARB_internalformat_query is supported, then treat its highest
 168     * returned sample count as the absolute maximum for this format; it is
 169     * allowed to exceed MAX_SAMPLES.
 170     *
 171     * From the ARB_internalformat_query spec:
 172     *
 173     * "If <samples is greater than the maximum number of samples supported
 174     * for <internalformat> then the error INVALID_OPERATION is generated."
 175     */
 176    if (ctx->Extensions.ARB_internalformat_query) {
 177       GLint buffer[16] = {-1};
 178       GLint limit;
 179
 180       ctx->Driver.QueryInternalFormat(ctx, target, internalFormat,
 181                                       GL_SAMPLES, buffer);
 182       /* since the query returns samples sorted in descending order,
 183        * the first element is the greatest supported sample value.
 184        */
 185       limit = buffer[0];
 186
 187       return samples > limit ? GL_INVALID_OPERATION : GL_NO_ERROR;
 188    }
 189
 190    /* If ARB_texture_multisample is supported, we have separate limits,
 191     * which may be lower than MAX_SAMPLES:
 192     *
 193     * From the ARB_texture_multisample spec, when describing the operation
 194     * of RenderbufferStorageMultisample:
 195     *
 196     * "If <internalformat> is a signed or unsigned integer format and
 197     * <samples> is greater than the value of MAX_INTEGER_SAMPLES, then the
 198     * error INVALID_OPERATION is generated"
 199     *
 200     * And when describing the operation of TexImage*Multisample:
 201     *
 202     * "The error INVALID_OPERATION may be generated if any of the following
 203     * are true:
 204     *
 205     * * <internalformat> is a depth/stencil-renderable format and <samples>
 206     *   is greater than the value of MAX_DEPTH_TEXTURE_SAMPLES
 207     * * <internalformat> is a color-renderable format and <samples> is
 208     *   grater than the value of MAX_COLOR_TEXTURE_SAMPLES
 209     * * <internalformat> is a signed or unsigned integer format and
 210     *   <samples> is greater than the value of MAX_INTEGER_SAMPLES
 211     */
 212
 213    if (ctx->Extensions.ARB_texture_multisample) {
 214       if (_mesa_is_enum_format_integer(internalFormat))
 215          return samples > ctx->Const.MaxIntegerSamples
 216             ? GL_INVALID_OPERATION : GL_NO_ERROR;
 217
 218       if (target == GL_TEXTURE_2D_MULTISAMPLE ||
 219           target == GL_TEXTURE_2D_MULTISAMPLE_ARRAY) {
 220
 221          if (_mesa_is_depth_or_stencil_format(internalFormat))
 222             return samples > ctx->Const.MaxDepthTextureSamples
 223                ? GL_INVALID_OPERATION : GL_NO_ERROR;
 224          else
 225             return samples > ctx->Const.MaxColorTextureSamples
 226                ? GL_INVALID_OPERATION : GL_NO_ERROR;
 227       }
 228    }
 229
 230    /* No more specific limit is available, so just use MAX_SAMPLES:
 231     *
 232     * On p205 of the GL3.1 spec:
 233     *
 234     * "... or if samples is greater than MAX_SAMPLES, then the error
 235     * INVALID_VALUE is generated"
 236     */
 237    return (GLuint) samples > ctx->Const.MaxSamples
 238       ? GL_INVALID_VALUE : GL_NO_ERROR;
 239 }