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