gecko/dom/canvas/WebGLContextDraw.cpp
2014-11-13 20:03:50 -08:00

785 lines
26 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "WebGLContext.h"
#include "GLContext.h"
#include "mozilla/CheckedInt.h"
#include "WebGLBuffer.h"
#include "WebGLContextUtils.h"
#include "WebGLFramebuffer.h"
#include "WebGLProgram.h"
#include "WebGLRenderbuffer.h"
#include "WebGLShader.h"
#include "WebGLTexture.h"
#include "WebGLUniformInfo.h"
#include "WebGLVertexArray.h"
#include "WebGLVertexAttribData.h"
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::gl;
// For a Tegra workaround.
static const int MAX_DRAW_CALLS_SINCE_FLUSH = 100;
bool
WebGLContext::DrawInstanced_check(const char* info)
{
// This restriction was removed in GLES3, so WebGL2 shouldn't have it.
if (!IsWebGL2() &&
IsExtensionEnabled(WebGLExtensionID::ANGLE_instanced_arrays) &&
!mBufferFetchingHasPerVertex)
{
/* http://www.khronos.org/registry/gles/extensions/ANGLE/ANGLE_instanced_arrays.txt
* If all of the enabled vertex attribute arrays that are bound to active
* generic attributes in the program have a non-zero divisor, the draw
* call should return INVALID_OPERATION.
*
* NB: This also appears to apply to NV_instanced_arrays, though the
* INVALID_OPERATION emission is not explicitly stated.
* ARB_instanced_arrays does not have this restriction.
*/
ErrorInvalidOperation("%s: at least one vertex attribute divisor should be 0", info);
return false;
}
return true;
}
bool WebGLContext::DrawArrays_check(GLint first, GLsizei count, GLsizei primcount, const char* info)
{
if (first < 0 || count < 0) {
ErrorInvalidValue("%s: negative first or count", info);
return false;
}
if (primcount < 0) {
ErrorInvalidValue("%s: negative primcount", info);
return false;
}
if (!ValidateStencilParamsForDrawCall()) {
return false;
}
// If count is 0, there's nothing to do.
if (count == 0 || primcount == 0) {
return false;
}
// Any checks below this depend on a program being available.
if (!mCurrentProgram) {
ErrorInvalidOperation("%s: null CURRENT_PROGRAM", info);
return false;
}
if (!ValidateBufferFetching(info)) {
return false;
}
CheckedInt<GLsizei> checked_firstPlusCount = CheckedInt<GLsizei>(first) + count;
if (!checked_firstPlusCount.isValid()) {
ErrorInvalidOperation("%s: overflow in first+count", info);
return false;
}
if (uint32_t(checked_firstPlusCount.value()) > mMaxFetchedVertices) {
ErrorInvalidOperation("%s: bound vertex attribute buffers do not have sufficient size for given first and count", info);
return false;
}
if (uint32_t(primcount) > mMaxFetchedInstances) {
ErrorInvalidOperation("%s: bound instance attribute buffers do not have sufficient size for given primcount", info);
return false;
}
MakeContextCurrent();
if (mBoundFramebuffer) {
if (!mBoundFramebuffer->CheckAndInitializeAttachments()) {
ErrorInvalidFramebufferOperation("%s: incomplete framebuffer", info);
return false;
}
} else {
ClearBackbufferIfNeeded();
}
if (!DoFakeVertexAttrib0(checked_firstPlusCount.value())) {
return false;
}
if (!DrawInstanced_check(info)) {
return false;
}
BindFakeBlackTextures();
return true;
}
void
WebGLContext::DrawArrays(GLenum mode, GLint first, GLsizei count)
{
if (IsContextLost())
return;
if (!ValidateDrawModeEnum(mode, "drawArrays: mode"))
return;
if (!DrawArrays_check(first, count, 1, "drawArrays"))
return;
RunContextLossTimer();
{
ScopedMaskWorkaround autoMask(*this);
gl->fDrawArrays(mode, first, count);
}
Draw_cleanup();
}
void
WebGLContext::DrawArraysInstanced(GLenum mode, GLint first, GLsizei count, GLsizei primcount)
{
if (IsContextLost())
return;
if (!ValidateDrawModeEnum(mode, "drawArraysInstanced: mode"))
return;
if (!DrawArrays_check(first, count, primcount, "drawArraysInstanced"))
return;
RunContextLossTimer();
{
ScopedMaskWorkaround autoMask(*this);
gl->fDrawArraysInstanced(mode, first, count, primcount);
}
Draw_cleanup();
}
bool
WebGLContext::DrawElements_check(GLsizei count, GLenum type,
WebGLintptr byteOffset, GLsizei primcount,
const char* info, GLuint* out_upperBound)
{
if (count < 0 || byteOffset < 0) {
ErrorInvalidValue("%s: negative count or offset", info);
return false;
}
if (primcount < 0) {
ErrorInvalidValue("%s: negative primcount", info);
return false;
}
if (!ValidateStencilParamsForDrawCall()) {
return false;
}
// If count is 0, there's nothing to do.
if (count == 0 || primcount == 0) {
return false;
}
CheckedUint32 checked_byteCount;
GLsizei first = 0;
if (type == LOCAL_GL_UNSIGNED_SHORT) {
checked_byteCount = 2 * CheckedUint32(count);
if (byteOffset % 2 != 0) {
ErrorInvalidOperation("%s: invalid byteOffset for UNSIGNED_SHORT (must be a multiple of 2)", info);
return false;
}
first = byteOffset / 2;
}
else if (type == LOCAL_GL_UNSIGNED_BYTE) {
checked_byteCount = count;
first = byteOffset;
}
else if (type == LOCAL_GL_UNSIGNED_INT && IsExtensionEnabled(WebGLExtensionID::OES_element_index_uint)) {
checked_byteCount = 4 * CheckedUint32(count);
if (byteOffset % 4 != 0) {
ErrorInvalidOperation("%s: invalid byteOffset for UNSIGNED_INT (must be a multiple of 4)", info);
return false;
}
first = byteOffset / 4;
}
else {
ErrorInvalidEnum("%s: type must be UNSIGNED_SHORT or UNSIGNED_BYTE", info);
return false;
}
if (!checked_byteCount.isValid()) {
ErrorInvalidValue("%s: overflow in byteCount", info);
return false;
}
// Any checks below this depend on a program being available.
if (!mCurrentProgram) {
ErrorInvalidOperation("%s: null CURRENT_PROGRAM", info);
return false;
}
if (!mBoundVertexArray->mElementArrayBuffer) {
ErrorInvalidOperation("%s: must have element array buffer binding", info);
return false;
}
WebGLBuffer& elemArrayBuffer = *mBoundVertexArray->mElementArrayBuffer;
if (!elemArrayBuffer.ByteLength()) {
ErrorInvalidOperation("%s: bound element array buffer doesn't have any data", info);
return false;
}
CheckedInt<GLsizei> checked_neededByteCount = checked_byteCount.toChecked<GLsizei>() + byteOffset;
if (!checked_neededByteCount.isValid()) {
ErrorInvalidOperation("%s: overflow in byteOffset+byteCount", info);
return false;
}
if (uint32_t(checked_neededByteCount.value()) > elemArrayBuffer.ByteLength()) {
ErrorInvalidOperation("%s: bound element array buffer is too small for given count and offset", info);
return false;
}
if (!ValidateBufferFetching(info))
return false;
if (!mMaxFetchedVertices ||
!elemArrayBuffer.Validate(type, mMaxFetchedVertices - 1, first, count, out_upperBound))
{
ErrorInvalidOperation(
"%s: bound vertex attribute buffers do not have sufficient "
"size for given indices from the bound element array", info);
return false;
}
if (uint32_t(primcount) > mMaxFetchedInstances) {
ErrorInvalidOperation("%s: bound instance attribute buffers do not have sufficient size for given primcount", info);
return false;
}
// Bug 1008310 - Check if buffer has been used with a different previous type
if (elemArrayBuffer.IsElementArrayUsedWithMultipleTypes()) {
GenerateWarning("%s: bound element array buffer previously used with a type other than "
"%s, this will affect performance.",
info,
WebGLContext::EnumName(type));
}
MakeContextCurrent();
if (mBoundFramebuffer) {
if (!mBoundFramebuffer->CheckAndInitializeAttachments()) {
ErrorInvalidFramebufferOperation("%s: incomplete framebuffer", info);
return false;
}
} else {
ClearBackbufferIfNeeded();
}
if (!DoFakeVertexAttrib0(mMaxFetchedVertices)) {
return false;
}
if (!DrawInstanced_check(info)) {
return false;
}
BindFakeBlackTextures();
return true;
}
void
WebGLContext::DrawElements(GLenum mode, GLsizei count, GLenum type,
WebGLintptr byteOffset)
{
if (IsContextLost())
return;
if (!ValidateDrawModeEnum(mode, "drawElements: mode"))
return;
GLuint upperBound = 0;
if (!DrawElements_check(count, type, byteOffset, 1, "drawElements",
&upperBound))
{
return;
}
RunContextLossTimer();
{
ScopedMaskWorkaround autoMask(*this);
if (gl->IsSupported(gl::GLFeature::draw_range_elements)) {
gl->fDrawRangeElements(mode, 0, upperBound, count, type,
reinterpret_cast<GLvoid*>(byteOffset));
} else {
gl->fDrawElements(mode, count, type,
reinterpret_cast<GLvoid*>(byteOffset));
}
}
Draw_cleanup();
}
void
WebGLContext::DrawElementsInstanced(GLenum mode, GLsizei count, GLenum type,
WebGLintptr byteOffset, GLsizei primcount)
{
if (IsContextLost())
return;
if (!ValidateDrawModeEnum(mode, "drawElementsInstanced: mode"))
return;
GLuint upperBound = 0;
if (!DrawElements_check(count, type, byteOffset, primcount,
"drawElementsInstanced", &upperBound))
{
return;
}
RunContextLossTimer();
{
ScopedMaskWorkaround autoMask(*this);
gl->fDrawElementsInstanced(mode, count, type,
reinterpret_cast<GLvoid*>(byteOffset),
primcount);
}
Draw_cleanup();
}
void WebGLContext::Draw_cleanup()
{
UndoFakeVertexAttrib0();
UnbindFakeBlackTextures();
if (!mBoundFramebuffer) {
Invalidate();
mShouldPresent = true;
MOZ_ASSERT(!mBackbufferNeedsClear);
}
if (gl->WorkAroundDriverBugs()) {
if (gl->Renderer() == gl::GLRenderer::Tegra) {
mDrawCallsSinceLastFlush++;
if (mDrawCallsSinceLastFlush >= MAX_DRAW_CALLS_SINCE_FLUSH) {
gl->fFlush();
mDrawCallsSinceLastFlush = 0;
}
}
}
// Let's check the viewport
const WebGLRectangleObject* rect = CurValidFBRectObject();
if (rect) {
if (mViewportWidth > rect->Width() ||
mViewportHeight > rect->Height())
{
if (!mAlreadyWarnedAboutViewportLargerThanDest) {
GenerateWarning("Drawing to a destination rect smaller than the viewport rect. "
"(This warning will only be given once)");
mAlreadyWarnedAboutViewportLargerThanDest = true;
}
}
}
}
/*
* Verify that state is consistent for drawing, and compute max number of elements (maxAllowedCount)
* that will be legal to be read from bound VBOs.
*/
bool
WebGLContext::ValidateBufferFetching(const char* info)
{
#ifdef DEBUG
GLint currentProgram = 0;
MakeContextCurrent();
gl->fGetIntegerv(LOCAL_GL_CURRENT_PROGRAM, &currentProgram);
MOZ_ASSERT(GLuint(currentProgram) == mCurrentProgram->GLName(),
"WebGL: current program doesn't agree with GL state");
#endif
if (mBufferFetchingIsVerified)
return true;
bool hasPerVertex = false;
uint32_t maxVertices = UINT32_MAX;
uint32_t maxInstances = UINT32_MAX;
uint32_t attribs = mBoundVertexArray->mAttribs.Length();
for (uint32_t i = 0; i < attribs; ++i) {
const WebGLVertexAttribData& vd = mBoundVertexArray->mAttribs[i];
// If the attrib array isn't enabled, there's nothing to check;
// it's a static value.
if (!vd.enabled)
continue;
if (vd.buf == nullptr) {
ErrorInvalidOperation("%s: no VBO bound to enabled vertex attrib index %d!", info, i);
return false;
}
// If the attrib is not in use, then we don't have to validate
// it, just need to make sure that the binding is non-null.
if (!mCurrentProgram->IsAttribInUse(i))
continue;
// the base offset
CheckedUint32 checked_byteLength = CheckedUint32(vd.buf->ByteLength()) - vd.byteOffset;
CheckedUint32 checked_sizeOfLastElement = CheckedUint32(vd.componentSize()) * vd.size;
if (!checked_byteLength.isValid() ||
!checked_sizeOfLastElement.isValid())
{
ErrorInvalidOperation("%s: integer overflow occured while checking vertex attrib %d", info, i);
return false;
}
if (checked_byteLength.value() < checked_sizeOfLastElement.value()) {
maxVertices = 0;
maxInstances = 0;
break;
}
CheckedUint32 checked_maxAllowedCount = ((checked_byteLength - checked_sizeOfLastElement) / vd.actualStride()) + 1;
if (!checked_maxAllowedCount.isValid()) {
ErrorInvalidOperation("%s: integer overflow occured while checking vertex attrib %d", info, i);
return false;
}
if (vd.divisor == 0) {
maxVertices = std::min(maxVertices, checked_maxAllowedCount.value());
hasPerVertex = true;
} else {
CheckedUint32 checked_curMaxInstances = checked_maxAllowedCount * vd.divisor;
uint32_t curMaxInstances = UINT32_MAX;
// If this isn't valid, it's because we overflowed our
// uint32 above. Just leave this as UINT32_MAX, since
// sizeof(uint32) becomes our limiting factor.
if (checked_curMaxInstances.isValid()) {
curMaxInstances = checked_curMaxInstances.value();
}
maxInstances = std::min(maxInstances, curMaxInstances);
}
}
mBufferFetchingIsVerified = true;
mBufferFetchingHasPerVertex = hasPerVertex;
mMaxFetchedVertices = maxVertices;
mMaxFetchedInstances = maxInstances;
return true;
}
WebGLVertexAttrib0Status
WebGLContext::WhatDoesVertexAttrib0Need()
{
MOZ_ASSERT(mCurrentProgram);
// work around Mac OSX crash, see bug 631420
#ifdef XP_MACOSX
if (gl->WorkAroundDriverBugs() &&
mBoundVertexArray->IsAttribArrayEnabled(0) &&
!mCurrentProgram->IsAttribInUse(0))
{
return WebGLVertexAttrib0Status::EmulatedUninitializedArray;
}
#endif
if (MOZ_LIKELY(gl->IsGLES() ||
mBoundVertexArray->IsAttribArrayEnabled(0)))
{
return WebGLVertexAttrib0Status::Default;
}
return mCurrentProgram->IsAttribInUse(0)
? WebGLVertexAttrib0Status::EmulatedInitializedArray
: WebGLVertexAttrib0Status::EmulatedUninitializedArray;
}
bool
WebGLContext::DoFakeVertexAttrib0(GLuint vertexCount)
{
WebGLVertexAttrib0Status whatDoesAttrib0Need = WhatDoesVertexAttrib0Need();
if (MOZ_LIKELY(whatDoesAttrib0Need == WebGLVertexAttrib0Status::Default))
return true;
if (!mAlreadyWarnedAboutFakeVertexAttrib0) {
GenerateWarning("Drawing without vertex attrib 0 array enabled forces the browser "
"to do expensive emulation work when running on desktop OpenGL "
"platforms, for example on Mac. It is preferable to always draw "
"with vertex attrib 0 array enabled, by using bindAttribLocation "
"to bind some always-used attribute to location 0.");
mAlreadyWarnedAboutFakeVertexAttrib0 = true;
}
CheckedUint32 checked_dataSize = CheckedUint32(vertexCount) * 4 * sizeof(GLfloat);
if (!checked_dataSize.isValid()) {
ErrorOutOfMemory("Integer overflow trying to construct a fake vertex attrib 0 array for a draw-operation "
"with %d vertices. Try reducing the number of vertices.", vertexCount);
return false;
}
GLuint dataSize = checked_dataSize.value();
if (!mFakeVertexAttrib0BufferObject) {
gl->fGenBuffers(1, &mFakeVertexAttrib0BufferObject);
}
// if the VBO status is already exactly what we need, or if the only difference is that it's initialized and
// we don't need it to be, then consider it OK
bool vertexAttrib0BufferStatusOK =
mFakeVertexAttrib0BufferStatus == whatDoesAttrib0Need ||
(mFakeVertexAttrib0BufferStatus == WebGLVertexAttrib0Status::EmulatedInitializedArray &&
whatDoesAttrib0Need == WebGLVertexAttrib0Status::EmulatedUninitializedArray);
if (!vertexAttrib0BufferStatusOK ||
mFakeVertexAttrib0BufferObjectSize < dataSize ||
mFakeVertexAttrib0BufferObjectVector[0] != mVertexAttrib0Vector[0] ||
mFakeVertexAttrib0BufferObjectVector[1] != mVertexAttrib0Vector[1] ||
mFakeVertexAttrib0BufferObjectVector[2] != mVertexAttrib0Vector[2] ||
mFakeVertexAttrib0BufferObjectVector[3] != mVertexAttrib0Vector[3])
{
mFakeVertexAttrib0BufferStatus = whatDoesAttrib0Need;
mFakeVertexAttrib0BufferObjectSize = dataSize;
mFakeVertexAttrib0BufferObjectVector[0] = mVertexAttrib0Vector[0];
mFakeVertexAttrib0BufferObjectVector[1] = mVertexAttrib0Vector[1];
mFakeVertexAttrib0BufferObjectVector[2] = mVertexAttrib0Vector[2];
mFakeVertexAttrib0BufferObjectVector[3] = mVertexAttrib0Vector[3];
gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mFakeVertexAttrib0BufferObject);
GetAndFlushUnderlyingGLErrors();
if (mFakeVertexAttrib0BufferStatus == WebGLVertexAttrib0Status::EmulatedInitializedArray) {
UniquePtr<GLfloat[]> array(new ((fallible_t())) GLfloat[4 * vertexCount]);
if (!array) {
ErrorOutOfMemory("Fake attrib0 array.");
return false;
}
for(size_t i = 0; i < vertexCount; ++i) {
array[4 * i + 0] = mVertexAttrib0Vector[0];
array[4 * i + 1] = mVertexAttrib0Vector[1];
array[4 * i + 2] = mVertexAttrib0Vector[2];
array[4 * i + 3] = mVertexAttrib0Vector[3];
}
gl->fBufferData(LOCAL_GL_ARRAY_BUFFER, dataSize, array.get(), LOCAL_GL_DYNAMIC_DRAW);
} else {
gl->fBufferData(LOCAL_GL_ARRAY_BUFFER, dataSize, nullptr, LOCAL_GL_DYNAMIC_DRAW);
}
GLenum error = GetAndFlushUnderlyingGLErrors();
gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mBoundArrayBuffer ? mBoundArrayBuffer->GLName() : 0);
// note that we do this error checking and early return AFTER having restored the buffer binding above
if (error) {
ErrorOutOfMemory("Ran out of memory trying to construct a fake vertex attrib 0 array for a draw-operation "
"with %d vertices. Try reducing the number of vertices.", vertexCount);
return false;
}
}
gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mFakeVertexAttrib0BufferObject);
gl->fVertexAttribPointer(0, 4, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, 0);
return true;
}
void
WebGLContext::UndoFakeVertexAttrib0()
{
WebGLVertexAttrib0Status whatDoesAttrib0Need = WhatDoesVertexAttrib0Need();
if (MOZ_LIKELY(whatDoesAttrib0Need == WebGLVertexAttrib0Status::Default))
return;
if (mBoundVertexArray->HasAttrib(0) && mBoundVertexArray->mAttribs[0].buf) {
const WebGLVertexAttribData& attrib0 = mBoundVertexArray->mAttribs[0];
gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, attrib0.buf->GLName());
if (attrib0.integer) {
gl->fVertexAttribIPointer(0,
attrib0.size,
attrib0.type,
attrib0.stride,
reinterpret_cast<const GLvoid*>(attrib0.byteOffset));
} else {
gl->fVertexAttribPointer(0,
attrib0.size,
attrib0.type,
attrib0.normalized,
attrib0.stride,
reinterpret_cast<const GLvoid*>(attrib0.byteOffset));
}
} else {
gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
}
gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, mBoundArrayBuffer ? mBoundArrayBuffer->GLName() : 0);
}
WebGLContextFakeBlackStatus
WebGLContext::ResolvedFakeBlackStatus()
{
// handle this case first, it's the generic case
if (MOZ_LIKELY(mFakeBlackStatus == WebGLContextFakeBlackStatus::NotNeeded))
return mFakeBlackStatus;
if (mFakeBlackStatus == WebGLContextFakeBlackStatus::Needed)
return mFakeBlackStatus;
for (int32_t i = 0; i < mGLMaxTextureUnits; ++i) {
if ((mBound2DTextures[i] && mBound2DTextures[i]->ResolvedFakeBlackStatus() != WebGLTextureFakeBlackStatus::NotNeeded) ||
(mBoundCubeMapTextures[i] && mBoundCubeMapTextures[i]->ResolvedFakeBlackStatus() != WebGLTextureFakeBlackStatus::NotNeeded))
{
mFakeBlackStatus = WebGLContextFakeBlackStatus::Needed;
return mFakeBlackStatus;
}
}
// we have exhausted all cases where we do need fakeblack, so if the status is still unknown,
// that means that we do NOT need it.
mFakeBlackStatus = WebGLContextFakeBlackStatus::NotNeeded;
return mFakeBlackStatus;
}
void
WebGLContext::BindFakeBlackTexturesHelper(
GLenum target,
const nsTArray<WebGLRefPtr<WebGLTexture> > & boundTexturesArray,
UniquePtr<FakeBlackTexture> & opaqueTextureScopedPtr,
UniquePtr<FakeBlackTexture> & transparentTextureScopedPtr)
{
for (int32_t i = 0; i < mGLMaxTextureUnits; ++i) {
if (!boundTexturesArray[i]) {
continue;
}
WebGLTextureFakeBlackStatus s = boundTexturesArray[i]->ResolvedFakeBlackStatus();
MOZ_ASSERT(s != WebGLTextureFakeBlackStatus::Unknown);
if (MOZ_LIKELY(s == WebGLTextureFakeBlackStatus::NotNeeded)) {
continue;
}
bool alpha = s == WebGLTextureFakeBlackStatus::UninitializedImageData &&
FormatHasAlpha(boundTexturesArray[i]->ImageInfoBase().EffectiveInternalFormat());
UniquePtr<FakeBlackTexture>&
blackTexturePtr = alpha
? transparentTextureScopedPtr
: opaqueTextureScopedPtr;
if (!blackTexturePtr) {
GLenum format = alpha ? LOCAL_GL_RGBA : LOCAL_GL_RGB;
blackTexturePtr = MakeUnique<FakeBlackTexture>(gl, target, format);
}
gl->fActiveTexture(LOCAL_GL_TEXTURE0 + i);
gl->fBindTexture(target,
blackTexturePtr->GLName());
}
}
void
WebGLContext::BindFakeBlackTextures()
{
// this is the generic case: try to return early
if (MOZ_LIKELY(ResolvedFakeBlackStatus() == WebGLContextFakeBlackStatus::NotNeeded))
return;
BindFakeBlackTexturesHelper(LOCAL_GL_TEXTURE_2D,
mBound2DTextures,
mBlackOpaqueTexture2D,
mBlackTransparentTexture2D);
BindFakeBlackTexturesHelper(LOCAL_GL_TEXTURE_CUBE_MAP,
mBoundCubeMapTextures,
mBlackOpaqueTextureCubeMap,
mBlackTransparentTextureCubeMap);
}
void
WebGLContext::UnbindFakeBlackTextures()
{
// this is the generic case: try to return early
if (MOZ_LIKELY(ResolvedFakeBlackStatus() == WebGLContextFakeBlackStatus::NotNeeded))
return;
for (int32_t i = 0; i < mGLMaxTextureUnits; ++i) {
if (mBound2DTextures[i] && mBound2DTextures[i]->ResolvedFakeBlackStatus() != WebGLTextureFakeBlackStatus::NotNeeded) {
gl->fActiveTexture(LOCAL_GL_TEXTURE0 + i);
gl->fBindTexture(LOCAL_GL_TEXTURE_2D, mBound2DTextures[i]->GLName());
}
if (mBoundCubeMapTextures[i] && mBoundCubeMapTextures[i]->ResolvedFakeBlackStatus() != WebGLTextureFakeBlackStatus::NotNeeded) {
gl->fActiveTexture(LOCAL_GL_TEXTURE0 + i);
gl->fBindTexture(LOCAL_GL_TEXTURE_CUBE_MAP, mBoundCubeMapTextures[i]->GLName());
}
}
gl->fActiveTexture(LOCAL_GL_TEXTURE0 + mActiveTexture);
}
WebGLContext::FakeBlackTexture::FakeBlackTexture(GLContext* gl, TexTarget target, GLenum format)
: mGL(gl)
, mGLName(0)
{
MOZ_ASSERT(format == LOCAL_GL_RGB || format == LOCAL_GL_RGBA);
mGL->MakeCurrent();
GLuint formerBinding = 0;
gl->GetUIntegerv(target == LOCAL_GL_TEXTURE_2D
? LOCAL_GL_TEXTURE_BINDING_2D
: LOCAL_GL_TEXTURE_BINDING_CUBE_MAP,
&formerBinding);
gl->fGenTextures(1, &mGLName);
gl->fBindTexture(target.get(), mGLName);
// we allocate our zeros on the heap, and we overallocate (16 bytes instead of 4)
// to minimize the risk of running into a driver bug in texImage2D, as it is
// a bit unusual maybe to create 1x1 textures, and the stack may not have the alignment
// that texImage2D expects.
UniquePtr<uint8_t> zeros((uint8_t*)moz_xcalloc(1, 16));
if (target == LOCAL_GL_TEXTURE_2D) {
gl->fTexImage2D(target.get(), 0, format, 1, 1,
0, format, LOCAL_GL_UNSIGNED_BYTE, zeros.get());
} else {
for (GLuint i = 0; i < 6; ++i) {
gl->fTexImage2D(LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, format, 1, 1,
0, format, LOCAL_GL_UNSIGNED_BYTE, zeros.get());
}
}
gl->fBindTexture(target.get(), formerBinding);
}
WebGLContext::FakeBlackTexture::~FakeBlackTexture()
{
if (mGL) {
mGL->MakeCurrent();
mGL->fDeleteTextures(1, &mGLName);
}
}