WebGLContext::FakeBlackTexture::FakeBlackTexture(gl::GLContext* gl, TexTarget target,
FakeBlackType type)
: mGL(gl)
, mGLName(CreateGLTexture(gl))
{
GLenum texFormat;
switch (type) {
case FakeBlackType::RGBA0000:
texFormat = LOCAL_GL_RGBA;
break;
case FakeBlackType::RGBA0001:
texFormat = LOCAL_GL_RGB;
break;
default:
MOZ_CRASH("bad type");
}
gl::ScopedBindTexture scopedBind(mGL, mGLName, target.get());
mGL->fTexParameteri(target.get(), LOCAL_GL_TEXTURE_MIN_FILTER, LOCAL_GL_NEAREST);
mGL->fTexParameteri(target.get(), LOCAL_GL_TEXTURE_MAG_FILTER, LOCAL_GL_NEAREST);
// 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.
const webgl::DriverUnpackInfo dui = {texFormat, texFormat, LOCAL_GL_UNSIGNED_BYTE};
UniqueBuffer zeros = moz_xcalloc(1, 16); // Infallible allocation.
if (target == LOCAL_GL_TEXTURE_CUBE_MAP) {
for (int i = 0; i < 6; ++i) {
const TexImageTarget curTarget = LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X + i;
const GLenum error = DoTexImage(mGL, curTarget.get(), 0, &dui, 1, 1, 1,
zeros.get());
if (error)
MOZ_CRASH("Unexpected error during FakeBlack creation.");
}
} else {
const GLenum error = DoTexImage(mGL, target.get(), 0, &dui, 1, 1, 1,
zeros.get());
if (error)
MOZ_CRASH("Unexpected error during FakeBlack creation.");
}
}
static GLenum
DoTexOrSubImage(bool isSubImage, gl::GLContext* gl, TexImageTarget target, GLint level,
const DriverUnpackInfo* dui, GLint xOffset, GLint yOffset, GLint zOffset,
GLsizei width, GLsizei height, GLsizei depth, const void* data)
{
if (isSubImage) {
return DoTexSubImage(gl, target, level, xOffset, yOffset, zOffset, width, height,
depth, dui->ToPacking(), data);
} else {
return DoTexImage(gl, target, level, dui, width, height, depth, data);
}
}