dom/canvas/WebGL2ContextFramebuffers.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "WebGL2Context.h"
   7
   8 #include "GLContext.h"
   9 #include "GLScreenBuffer.h"
  10 #include "mozilla/CheckedInt.h"
  11 #include "WebGLContextUtils.h"
  12 #include "WebGLFormats.h"
  13 #include "WebGLFramebuffer.h"
  14
  15 namespace mozilla {
  16
  17 void WebGL2Context::BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1,
  18                                     GLint srcY1, GLint dstX0, GLint dstY0,
  19                                     GLint dstX1, GLint dstY1, GLbitfield mask,
  20                                     GLenum filter) {
  21   const FuncScope funcScope(*this, "blitFramebuffer");
  22   if (IsContextLost()) return;
  23
  24   const GLbitfield validBits = LOCAL_GL_COLOR_BUFFER_BIT |
  25                                LOCAL_GL_DEPTH_BUFFER_BIT |
  26                                LOCAL_GL_STENCIL_BUFFER_BIT;
  27   if ((mask | validBits) != validBits) {
  28     ErrorInvalidValue("Invalid bit set in mask.");
  29     return;
  30   }
  31
  32   switch (filter) {
  33     case LOCAL_GL_NEAREST:
  34     case LOCAL_GL_LINEAR:
  35       break;
  36     default:
  37       ErrorInvalidEnumInfo("filter", filter);
  38       return;
  39   }
  40
  41   // --
  42
  43   const auto fnLikelyOverflow = [](GLint p0, GLint p1) {
  44     auto checked = CheckedInt<GLint>(p1) - p0;
  45     checked = -checked;  // And check the negation!
  46     return !checked.isValid();
  47   };
  48
  49   if (fnLikelyOverflow(srcX0, srcX1) || fnLikelyOverflow(srcY0, srcY1) ||
  50       fnLikelyOverflow(dstX0, dstX1) || fnLikelyOverflow(dstY0, dstY1)) {
  51     ErrorInvalidValue("Likely-to-overflow large ranges are forbidden.");
  52     return;
  53   }
  54
  55   // --
  56
  57   if (!ValidateAndInitFB(mBoundReadFramebuffer) ||
  58       !ValidateAndInitFB(mBoundDrawFramebuffer)) {
  59     return;
  60   }
  61
  62   DoBindFB(mBoundReadFramebuffer, LOCAL_GL_READ_FRAMEBUFFER);
  63   DoBindFB(mBoundDrawFramebuffer, LOCAL_GL_DRAW_FRAMEBUFFER);
  64
  65   WebGLFramebuffer::BlitFramebuffer(this, srcX0, srcY0, srcX1, srcY1, dstX0,
  66                                     dstY0, dstX1, dstY1, mask, filter);
  67 }
  68
  69 ////
  70
  71 static bool ValidateBackbufferAttachmentEnum(WebGLContext* webgl,
  72                                              GLenum attachment) {
  73   switch (attachment) {
  74     case LOCAL_GL_COLOR:
  75     case LOCAL_GL_DEPTH:
  76     case LOCAL_GL_STENCIL:
  77       return true;
  78
  79     default:
  80       webgl->ErrorInvalidEnumInfo("attachment", attachment);
  81       return false;
  82   }
  83 }
  84
  85 static bool ValidateFramebufferAttachmentEnum(WebGLContext* webgl,
  86                                               GLenum attachment) {
  87   switch (attachment) {
  88     case LOCAL_GL_DEPTH_ATTACHMENT:
  89     case LOCAL_GL_STENCIL_ATTACHMENT:
  90     case LOCAL_GL_DEPTH_STENCIL_ATTACHMENT:
  91       return true;
  92   }
  93
  94   if (attachment < LOCAL_GL_COLOR_ATTACHMENT0) {
  95     webgl->ErrorInvalidEnumInfo("attachment", attachment);
  96     return false;
  97   }
  98
  99   if (attachment > webgl->LastColorAttachmentEnum()) {
 100     // That these errors have different types is ridiculous.
 101     webgl->ErrorInvalidOperation("Too-large LOCAL_GL_COLOR_ATTACHMENTn.");
 102     return false;
 103   }
 104
 105   return true;
 106 }
 107
 108 bool WebGLContext::ValidateInvalidateFramebuffer(
 109     GLenum target, const Range<const GLenum>& attachments,
 110     std::vector<GLenum>* const scopedVector,
 111     GLsizei* const out_glNumAttachments,
 112     const GLenum** const out_glAttachments) {
 113   if (IsContextLost()) return false;
 114
 115   if (!ValidateFramebufferTarget(target)) return false;
 116
 117   const WebGLFramebuffer* fb;
 118   bool isDefaultFB = false;
 119   switch (target) {
 120     case LOCAL_GL_FRAMEBUFFER:
 121     case LOCAL_GL_DRAW_FRAMEBUFFER:
 122       fb = mBoundDrawFramebuffer;
 123       break;
 124
 125     case LOCAL_GL_READ_FRAMEBUFFER:
 126       fb = mBoundReadFramebuffer;
 127       break;
 128
 129     default:
 130       MOZ_CRASH("GFX: Bad target.");
 131   }
 132
 133   if (fb) {
 134     const auto fbStatus = fb->CheckFramebufferStatus();
 135     if (fbStatus != LOCAL_GL_FRAMEBUFFER_COMPLETE)
 136       return false;  // Not an error, but don't run forward to driver either.
 137   } else {
 138     if (!EnsureDefaultFB()) return false;
 139   }
 140   DoBindFB(fb, target);
 141
 142   *out_glNumAttachments = attachments.length();
 143   *out_glAttachments = attachments.begin().get();
 144
 145   if (fb) {
 146     for (const auto& attachment : attachments) {
 147       if (!ValidateFramebufferAttachmentEnum(this, attachment)) return false;
 148     }
 149   } else {
 150     for (const auto& attachment : attachments) {
 151       if (!ValidateBackbufferAttachmentEnum(this, attachment)) return false;
 152     }
 153
 154     if (!isDefaultFB) {
 155       MOZ_ASSERT(scopedVector->empty());
 156       scopedVector->reserve(attachments.length());
 157       for (const auto& attachment : attachments) {
 158         switch (attachment) {
 159           case LOCAL_GL_COLOR:
 160             scopedVector->push_back(LOCAL_GL_COLOR_ATTACHMENT0);
 161             break;
 162
 163           case LOCAL_GL_DEPTH:
 164             scopedVector->push_back(LOCAL_GL_DEPTH_ATTACHMENT);
 165             break;
 166
 167           case LOCAL_GL_STENCIL:
 168             scopedVector->push_back(LOCAL_GL_STENCIL_ATTACHMENT);
 169             break;
 170
 171           default:
 172             MOZ_CRASH();
 173         }
 174       }
 175       *out_glNumAttachments = scopedVector->size();
 176       *out_glAttachments = scopedVector->data();
 177     }
 178   }
 179
 180   ////
 181
 182   return true;
 183 }
 184
 185 void WebGL2Context::InvalidateFramebuffer(
 186     GLenum target, const Range<const GLenum>& attachments) {
 187   const FuncScope funcScope(*this, "invalidateFramebuffer");
 188
 189   std::vector<GLenum> scopedVector;
 190   GLsizei glNumAttachments;
 191   const GLenum* glAttachments;
 192   if (!ValidateInvalidateFramebuffer(target, attachments, &scopedVector,
 193                                      &glNumAttachments, &glAttachments)) {
 194     return;
 195   }
 196
 197   ////
 198
 199   // Some drivers (like OSX 10.9 GL) just don't support invalidate_framebuffer.
 200   const bool useFBInvalidation =
 201       (mAllowFBInvalidation &&
 202        gl->IsSupported(gl::GLFeature::invalidate_framebuffer));
 203   if (useFBInvalidation) {
 204     gl->fInvalidateFramebuffer(target, glNumAttachments, glAttachments);
 205     return;
 206   }
 207
 208   // Use clear instead?
 209   // No-op for now.
 210 }
 211
 212 void WebGL2Context::InvalidateSubFramebuffer(
 213     GLenum target, const Range<const GLenum>& attachments, GLint x, GLint y,
 214     GLsizei width, GLsizei height) {
 215   const FuncScope funcScope(*this, "invalidateSubFramebuffer");
 216
 217   std::vector<GLenum> scopedVector;
 218   GLsizei glNumAttachments;
 219   const GLenum* glAttachments;
 220   if (!ValidateInvalidateFramebuffer(target, attachments, &scopedVector,
 221                                      &glNumAttachments, &glAttachments)) {
 222     return;
 223   }
 224
 225   if (!ValidateNonNegative("width", width) ||
 226       !ValidateNonNegative("height", height)) {
 227     return;
 228   }
 229
 230   ////
 231
 232   // Some drivers (like OSX 10.9 GL) just don't support invalidate_framebuffer.
 233   const bool useFBInvalidation =
 234       (mAllowFBInvalidation &&
 235        gl->IsSupported(gl::GLFeature::invalidate_framebuffer));
 236   if (useFBInvalidation) {
 237     gl->fInvalidateSubFramebuffer(target, glNumAttachments, glAttachments, x, y,
 238                                   width, height);
 239     return;
 240   }
 241
 242   // Use clear instead?
 243   // No-op for now.
 244 }
 245
 246 void WebGL2Context::ReadBuffer(GLenum mode) {
 247   const FuncScope funcScope(*this, "readBuffer");
 248   if (IsContextLost()) return;
 249
 250   if (mBoundReadFramebuffer) {
 251     mBoundReadFramebuffer->ReadBuffer(mode);
 252     return;
 253   }
 254
 255   // Operating on the default framebuffer.
 256   if (mode != LOCAL_GL_NONE && mode != LOCAL_GL_BACK) {
 257     nsCString enumName;
 258     EnumName(mode, &enumName);
 259     ErrorInvalidOperation(
 260         "If READ_FRAMEBUFFER is null, `mode` must be BACK or"
 261         " NONE. Was %s.",
 262         enumName.BeginReading());
 263     return;
 264   }
 265
 266   mDefaultFB_ReadBuffer = mode;
 267 }
 268
 269 }  // namespace mozilla