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    value = CLAMP(value, 0.0f, 1.0f);
  45
  46    if (ctx->Multisample.SampleCoverageInvert == invert &&
  47        ctx->Multisample.SampleCoverageValue == value)
  48       return;
  49
  50    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewSampleMask ? 0 : _NEW_MULTISAMPLE);
  51    ctx->NewDriverState |= ctx->DriverFlags.NewSampleMask;
  52    ctx->Multisample.SampleCoverageValue = value;
  53    ctx->Multisample.SampleCoverageInvert = invert;
  54 }
  55
  56
  57 /**
  58  * Initialize the context's multisample state.
  59  * \param ctx  the GL context.
  60  */
  61 void
  62 _mesa_init_multisample(struct gl_context *ctx)
  63 {
  64    ctx->Multisample.Enabled = GL_TRUE;
  65    ctx->Multisample.SampleAlphaToCoverage = GL_FALSE;
  66    ctx->Multisample.SampleAlphaToOne = GL_FALSE;
  67    ctx->Multisample.SampleCoverage = GL_FALSE;
  68    ctx->Multisample.SampleCoverageValue = 1.0;
  69    ctx->Multisample.SampleCoverageInvert = GL_FALSE;
  70
  71    /* ARB_texture_multisample / GL3.2 additions */
  72    ctx->Multisample.SampleMask = GL_FALSE;
  73    ctx->Multisample.SampleMaskValue = ~(GLbitfield)0;
  74 }
  75
  76
  77 void GLAPIENTRY
  78 _mesa_GetMultisamplefv(GLenum pname, GLuint index, GLfloat * val)
  79 {
  80    GET_CURRENT_CONTEXT(ctx);
  81
  82    if (ctx->NewState & _NEW_BUFFERS) {
  83       _mesa_update_state(ctx);
  84    }
  85
  86    switch (pname) {
  87    case GL_SAMPLE_POSITION: {
  88       if ((int) index >= ctx->DrawBuffer->Visual.samples) {
  89          _mesa_error( ctx, GL_INVALID_VALUE, "glGetMultisamplefv(index)" );
  90          return;
  91       }
  92
  93       ctx->Driver.GetSamplePosition(ctx, ctx->DrawBuffer, index, val);
  94
  95       /* winsys FBOs are upside down */
  96       if (_mesa_is_winsys_fbo(ctx->DrawBuffer))
  97          val[1] = 1.0f - val[1];
  98
  99       return;
 100    }
 101
 102    default:
 103       _mesa_error( ctx, GL_INVALID_ENUM, "glGetMultisamplefv(pname)" );
 104       return;
 105    }
 106 }
 107
 108 void GLAPIENTRY
 109 _mesa_SampleMaski(GLuint index, GLbitfield mask)
 110 {
 111    GET_CURRENT_CONTEXT(ctx);
 112
 113    if (!ctx->Extensions.ARB_texture_multisample) {
 114       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleMaski");
 115       return;
 116    }
 117
 118    if (index != 0) {
 119       _mesa_error(ctx, GL_INVALID_VALUE, "glSampleMaski(index)");
 120       return;
 121    }
 122
 123    if (ctx->Multisample.SampleMaskValue == mask)
 124       return;
 125
 126    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewSampleMask ? 0 : _NEW_MULTISAMPLE);
 127    ctx->NewDriverState |= ctx->DriverFlags.NewSampleMask;
 128    ctx->Multisample.SampleMaskValue = mask;
 129 }
 130
 131 /**
 132  * Called via glMinSampleShadingARB
 133  */
 134 void GLAPIENTRY
 135 _mesa_MinSampleShading(GLclampf value)
 136 {
 137    GET_CURRENT_CONTEXT(ctx);
 138
 139    if (!_mesa_has_ARB_sample_shading(ctx) &&
 140        !_mesa_has_OES_sample_shading(ctx)) {
 141       _mesa_error(ctx, GL_INVALID_OPERATION, "glMinSampleShading");
 142       return;
 143    }
 144
 145    value = CLAMP(value, 0.0f, 1.0f);
 146
 147    if (ctx->Multisample.MinSampleShadingValue == value)
 148       return;
 149
 150    FLUSH_VERTICES(ctx,
 151                   ctx->DriverFlags.NewSampleShading ? 0 : _NEW_MULTISAMPLE);
 152    ctx->NewDriverState |= ctx->DriverFlags.NewSampleShading;
 153    ctx->Multisample.MinSampleShadingValue = value;
 154 }
 155
 156 /**
 157  * Helper for checking a requested sample count against the limit
 158  * for a particular (target, internalFormat) pair. The limit imposed,
 159  * and the error generated, both depend on which extensions are supported.
 160  *
 161  * Returns a GL error enum, or GL_NO_ERROR if the requested sample count is
 162  * acceptable.
 163  */
 164 GLenum
 165 _mesa_check_sample_count(struct gl_context *ctx, GLenum target,
 166                          GLenum internalFormat, GLsizei samples)
 167 {
 168    /* Section 4.4 (Framebuffer objects), page 198 of the OpenGL ES 3.0.0
 169     * specification says:
 170     *
 171     *     "If internalformat is a signed or unsigned integer format and samples
 172     *     is greater than zero, then the error INVALID_OPERATION is generated."
 173     *
 174     * This restriction is relaxed for OpenGL ES 3.1.
 175     */
 176    if ((ctx->API == API_OPENGLES2 && ctx->Version == 30) &&
 177        _mesa_is_enum_format_integer(internalFormat)
 178        && samples > 0) {
 179       return GL_INVALID_OPERATION;
 180    }
 181
 182    /* If ARB_internalformat_query is supported, then treat its highest
 183     * returned sample count as the absolute maximum for this format; it is
 184     * allowed to exceed MAX_SAMPLES.
 185     *
 186     * From the ARB_internalformat_query spec:
 187     *
 188     * "If <samples is greater than the maximum number of samples supported
 189     * for <internalformat> then the error INVALID_OPERATION is generated."
 190     */
 191    if (ctx->Extensions.ARB_internalformat_query) {
 192       GLint buffer[16] = {-1};
 193       GLint limit;
 194
 195       ctx->Driver.QueryInternalFormat(ctx, target, internalFormat,
 196                                       GL_SAMPLES, buffer);
 197       /* since the query returns samples sorted in descending order,
 198        * the first element is the greatest supported sample value.
 199        */
 200       limit = buffer[0];
 201
 202       return samples > limit ? GL_INVALID_OPERATION : GL_NO_ERROR;
 203    }
 204
 205    /* If ARB_texture_multisample is supported, we have separate limits,
 206     * which may be lower than MAX_SAMPLES:
 207     *
 208     * From the ARB_texture_multisample spec, when describing the operation
 209     * of RenderbufferStorageMultisample:
 210     *
 211     * "If <internalformat> is a signed or unsigned integer format and
 212     * <samples> is greater than the value of MAX_INTEGER_SAMPLES, then the
 213     * error INVALID_OPERATION is generated"
 214     *
 215     * And when describing the operation of TexImage*Multisample:
 216     *
 217     * "The error INVALID_OPERATION may be generated if any of the following
 218     * are true:
 219     *
 220     * * <internalformat> is a depth/stencil-renderable format and <samples>
 221     *   is greater than the value of MAX_DEPTH_TEXTURE_SAMPLES
 222     * * <internalformat> is a color-renderable format and <samples> is
 223     *   grater than the value of MAX_COLOR_TEXTURE_SAMPLES
 224     * * <internalformat> is a signed or unsigned integer format and
 225     *   <samples> is greater than the value of MAX_INTEGER_SAMPLES
 226     */
 227
 228    if (ctx->Extensions.ARB_texture_multisample) {
 229       if (_mesa_is_enum_format_integer(internalFormat))
 230          return samples > ctx->Const.MaxIntegerSamples
 231             ? GL_INVALID_OPERATION : GL_NO_ERROR;
 232
 233       if (target == GL_TEXTURE_2D_MULTISAMPLE ||
 234           target == GL_TEXTURE_2D_MULTISAMPLE_ARRAY) {
 235
 236          if (_mesa_is_depth_or_stencil_format(internalFormat))
 237             return samples > ctx->Const.MaxDepthTextureSamples
 238                ? GL_INVALID_OPERATION : GL_NO_ERROR;
 239          else
 240             return samples > ctx->Const.MaxColorTextureSamples
 241                ? GL_INVALID_OPERATION : GL_NO_ERROR;
 242       }
 243    }
 244
 245    /* No more specific limit is available, so just use MAX_SAMPLES:
 246     *
 247     * On p205 of the GL3.1 spec:
 248     *
 249     * "... or if samples is greater than MAX_SAMPLES, then the error
 250     * INVALID_VALUE is generated"
 251     */
 252    return (GLuint) samples > ctx->Const.MaxSamples
 253       ? GL_INVALID_VALUE : GL_NO_ERROR;
 254 }