bool
SharedSurface_IOSurface::ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height,
GLenum format, GLenum type, GLvoid* pixels)
{
// Calling glReadPixels when an IOSurface is bound to the current framebuffer
// can cause corruption in following glReadPixel calls (even if they aren't
// reading from an IOSurface).
// We workaround this by copying to a temporary texture, and doing the readback
// from that.
MOZ_ASSERT(mGL->IsCurrent());
ScopedTexture destTex(mGL);
{
ScopedFramebufferForTexture srcFB(mGL, ProdTexture(), ProdTextureTarget());
ScopedBindFramebuffer bindFB(mGL, srcFB.FB());
ScopedBindTexture bindTex(mGL, destTex.Texture());
mGL->raw_fCopyTexImage2D(LOCAL_GL_TEXTURE_2D, 0,
mHasAlpha ? LOCAL_GL_RGBA : LOCAL_GL_RGB,
x, y,
width, height, 0);
}
ScopedFramebufferForTexture destFB(mGL, destTex.Texture());
ScopedBindFramebuffer bindFB(mGL, destFB.FB());
mGL->raw_fReadPixels(0, 0, width, height, format, type, pixels);
return true;
}
static inline void newTex(GLuint tex, int w, int h, GLint internalFormat, GLenum format) {
const auto target = GL_TEXTURE_2D;
bindTex(tex, target);
glTexImage2D(target, 0, internalFormat, w, h, 0, format, GL_UNSIGNED_BYTE, nullptr);
glTexParameterf(target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameterf(target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
}
bool
SharedSurface_IOSurface::CopyTexImage2D(GLenum target, GLint level, GLenum internalformat,
GLint x, GLint y, GLsizei width, GLsizei height,
GLint border)
{
/* Bug 896693 - OpenGL framebuffers that are backed by IOSurface on OSX expose a bug
* in glCopyTexImage2D --- internalformats GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA
* return the wrong results. To work around, copy framebuffer to a temporary texture
* using GL_RGBA (which works), attach as read framebuffer and glCopyTexImage2D
* instead.
*/
// https://www.opengl.org/sdk/docs/man3/xhtml/glCopyTexImage2D.xml says that width or
// height set to 0 results in a NULL texture. Lets not do any work and punt to
// original glCopyTexImage2D, since the FBO below will fail when trying to attach a
// texture of 0 width or height.
if (width == 0 || height == 0)
return false;
switch (internalformat) {
case LOCAL_GL_ALPHA:
case LOCAL_GL_LUMINANCE:
case LOCAL_GL_LUMINANCE_ALPHA:
break;
default:
return false;
}
MOZ_ASSERT(mGL->IsCurrent());
ScopedTexture destTex(mGL);
{
ScopedBindTexture bindTex(mGL, destTex.Texture());
mGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MIN_FILTER,
LOCAL_GL_NEAREST);
mGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_MAG_FILTER,
LOCAL_GL_NEAREST);
mGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_WRAP_S,
LOCAL_GL_CLAMP_TO_EDGE);
mGL->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_WRAP_T,
LOCAL_GL_CLAMP_TO_EDGE);
mGL->raw_fCopyTexImage2D(LOCAL_GL_TEXTURE_2D, 0, LOCAL_GL_RGBA, x, y, width,
height, 0);
}
ScopedFramebufferForTexture tmpFB(mGL, destTex.Texture(), LOCAL_GL_TEXTURE_2D);
ScopedBindFramebuffer bindFB(mGL, tmpFB.FB());
mGL->raw_fCopyTexImage2D(target, level, internalformat, x, y, width, height, border);
return true;
}
static inline void activeTex(GLuint tex, int num, GLenum target = GL_TEXTURE_2D) {
glActiveTexture(GL_TEXTURE0 + num);
bindTex(tex, target);
}
static inline void uploadTex(GLuint tex, int w, int h, GLenum format, const void *data) {
const auto target = GL_TEXTURE_2D;
bindTex(tex, target);
glTexSubImage2D(target, 0, 0, 0, w, h, format, GL_UNSIGNED_BYTE, data);
}
