SkWGLPbufferContext* SkWGLPbufferContext::Create(HDC parentDC, int msaaSampleCount,
SkWGLContextRequest contextType) {
SkWGLExtensions extensions;
if (!extensions.hasExtension(parentDC, "WGL_ARB_pixel_format") ||
!extensions.hasExtension(parentDC, "WGL_ARB_pbuffer")) {
return nullptr;
}
// try for single buffer first
for (int dblBuffer = 0; dblBuffer < 2; ++dblBuffer) {
int pixelFormatsToTry[] = { -1, -1 };
get_pixel_formats_to_try(parentDC, extensions, (0 != dblBuffer), msaaSampleCount,
false, pixelFormatsToTry);
for (int f = 0; -1 != pixelFormatsToTry[f] && f < SK_ARRAY_COUNT(pixelFormatsToTry); ++f) {
HPBUFFER pbuf = extensions.createPbuffer(parentDC, pixelFormatsToTry[f], 1, 1, nullptr);
if (0 != pbuf) {
HDC dc = extensions.getPbufferDC(pbuf);
if (dc) {
HGLRC glrc = create_gl_context(dc, extensions, contextType);
if (glrc) {
return new SkWGLPbufferContext(pbuf, dc, glrc);
}
extensions.releasePbufferDC(pbuf, dc);
}
extensions.destroyPbuffer(pbuf);
}
}
}
return nullptr;
}
static void get_pixel_formats_to_try(HDC dc, const SkWGLExtensions& extensions,
bool doubleBuffered, int msaaSampleCount, bool deepColor,
int formatsToTry[2]) {
auto appendAttr = [](SkTDArray<int>& attrs, int attr, int value) {
attrs.push(attr);
attrs.push(value);
};
SkTDArray<int> iAttrs;
appendAttr(iAttrs, SK_WGL_DRAW_TO_WINDOW, TRUE);
appendAttr(iAttrs, SK_WGL_DOUBLE_BUFFER, (doubleBuffered ? TRUE : FALSE));
appendAttr(iAttrs, SK_WGL_ACCELERATION, SK_WGL_FULL_ACCELERATION);
appendAttr(iAttrs, SK_WGL_SUPPORT_OPENGL, TRUE);
if (deepColor) {
appendAttr(iAttrs, SK_WGL_RED_BITS, 10);
appendAttr(iAttrs, SK_WGL_GREEN_BITS, 10);
appendAttr(iAttrs, SK_WGL_BLUE_BITS, 10);
appendAttr(iAttrs, SK_WGL_ALPHA_BITS, 2);
} else {
appendAttr(iAttrs, SK_WGL_COLOR_BITS, 24);
appendAttr(iAttrs, SK_WGL_ALPHA_BITS, 8);
}
appendAttr(iAttrs, SK_WGL_STENCIL_BITS, 8);
float fAttrs[] = {0, 0};
// Get a MSAA format if requested and possible.
if (msaaSampleCount > 0 &&
extensions.hasExtension(dc, "WGL_ARB_multisample")) {
SkTDArray<int> msaaIAttrs = iAttrs;
appendAttr(msaaIAttrs, SK_WGL_SAMPLE_BUFFERS, TRUE);
appendAttr(msaaIAttrs, SK_WGL_SAMPLES, msaaSampleCount);
appendAttr(msaaIAttrs, 0, 0);
unsigned int num;
int formats[64];
extensions.choosePixelFormat(dc, msaaIAttrs.begin(), fAttrs, 64, formats, &num);
num = SkTMin(num, 64U);
formatsToTry[0] = extensions.selectFormat(formats, num, dc, msaaSampleCount);
}
// Get a non-MSAA format
int* format = -1 == formatsToTry[0] ? &formatsToTry[0] : &formatsToTry[1];
unsigned int num;
appendAttr(iAttrs, 0, 0);
extensions.choosePixelFormat(dc, iAttrs.begin(), fAttrs, 1, format, &num);
}
bool SkOSWindow::attachGL(int msaaSampleCount, bool deepColor, AttachmentInfo* info) {
HDC dc = GetDC((HWND)fHWND);
if (NULL == fHGLRC) {
fHGLRC = SkCreateWGLContext(dc, msaaSampleCount, deepColor,
kGLPreferCompatibilityProfile_SkWGLContextRequest);
if (NULL == fHGLRC) {
return false;
}
glClearStencil(0);
glClearColor(0, 0, 0, 0);
glStencilMask(0xffffffff);
glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
}
if (wglMakeCurrent(dc, (HGLRC)fHGLRC)) {
// use DescribePixelFormat to get the stencil and color bit depth.
int pixelFormat = GetPixelFormat(dc);
PIXELFORMATDESCRIPTOR pfd;
DescribePixelFormat(dc, pixelFormat, sizeof(pfd), &pfd);
info->fStencilBits = pfd.cStencilBits;
// pfd.cColorBits includes alpha, so it will be 32 in 8/8/8/8 and 10/10/10/2
info->fColorBits = pfd.cRedBits + pfd.cGreenBits + pfd.cBlueBits;
// Get sample count if the MSAA WGL extension is present
SkWGLExtensions extensions;
if (extensions.hasExtension(dc, "WGL_ARB_multisample")) {
static const int kSampleCountAttr = SK_WGL_SAMPLES;
extensions.getPixelFormatAttribiv(dc,
pixelFormat,
0,
1,
&kSampleCountAttr,
&info->fSampleCount);
} else {
info->fSampleCount = 0;
}
glViewport(0, 0,
SkScalarRoundToInt(this->width()),
SkScalarRoundToInt(this->height()));
return true;
}
return false;
}
HGLRC SkCreateWGLContext(HDC dc, int msaaSampleCount, bool deepColor,
SkWGLContextRequest contextType) {
SkWGLExtensions extensions;
if (!extensions.hasExtension(dc, "WGL_ARB_pixel_format")) {
return nullptr;
}
BOOL set = FALSE;
int pixelFormatsToTry[] = { -1, -1 };
get_pixel_formats_to_try(dc, extensions, true, msaaSampleCount, deepColor, pixelFormatsToTry);
for (int f = 0;
!set && -1 != pixelFormatsToTry[f] && f < SK_ARRAY_COUNT(pixelFormatsToTry);
++f) {
PIXELFORMATDESCRIPTOR pfd;
DescribePixelFormat(dc, pixelFormatsToTry[f], sizeof(pfd), &pfd);
set = SetPixelFormat(dc, pixelFormatsToTry[f], &pfd);
}
if (!set) {
return nullptr;
}
return create_gl_context(dc, extensions, contextType);}
static HGLRC create_gl_context(HDC dc, SkWGLExtensions extensions, SkWGLContextRequest contextType) {
HDC prevDC = wglGetCurrentDC();
HGLRC prevGLRC = wglGetCurrentContext();
HGLRC glrc = nullptr;
if (kGLES_SkWGLContextRequest == contextType) {
if (!extensions.hasExtension(dc, "WGL_EXT_create_context_es2_profile")) {
wglMakeCurrent(prevDC, prevGLRC);
return nullptr;
}
static const int glesAttribs[] = {
SK_WGL_CONTEXT_MAJOR_VERSION, 3,
SK_WGL_CONTEXT_MINOR_VERSION, 0,
SK_WGL_CONTEXT_PROFILE_MASK, SK_WGL_CONTEXT_ES2_PROFILE_BIT,
0,
};
glrc = extensions.createContextAttribs(dc, nullptr, glesAttribs);
if (nullptr == glrc) {
wglMakeCurrent(prevDC, prevGLRC);
return nullptr;
}
} else {
if (kGLPreferCoreProfile_SkWGLContextRequest == contextType &&
extensions.hasExtension(dc, "WGL_ARB_create_context")) {
static const int kCoreGLVersions[] = {
4, 3,
4, 2,
4, 1,
4, 0,
3, 3,
3, 2,
};
int coreProfileAttribs[] = {
SK_WGL_CONTEXT_MAJOR_VERSION, -1,
SK_WGL_CONTEXT_MINOR_VERSION, -1,
SK_WGL_CONTEXT_PROFILE_MASK, SK_WGL_CONTEXT_CORE_PROFILE_BIT,
0,
};
for (int v = 0; v < SK_ARRAY_COUNT(kCoreGLVersions) / 2; ++v) {
coreProfileAttribs[1] = kCoreGLVersions[2 * v];
coreProfileAttribs[3] = kCoreGLVersions[2 * v + 1];
glrc = extensions.createContextAttribs(dc, nullptr, coreProfileAttribs);
if (glrc) {
break;
}
}
}
}
if (nullptr == glrc) {
glrc = wglCreateContext(dc);
}
SkASSERT(glrc);
wglMakeCurrent(prevDC, prevGLRC);
// This might help make the context non-vsynced.
if (extensions.hasExtension(dc, "WGL_EXT_swap_control")) {
extensions.swapInterval(-1);
}
return glrc;
}
HGLRC SkCreateWGLContext(HDC dc, int msaaSampleCount, bool preferCoreProfile) {
SkWGLExtensions extensions;
if (!extensions.hasExtension(dc, "WGL_ARB_pixel_format")) {
return NULL;
}
HDC prevDC = wglGetCurrentDC();
HGLRC prevGLRC = wglGetCurrentContext();
PIXELFORMATDESCRIPTOR pfd;
int format = 0;
static const int iAttrs[] = {
SK_WGL_DRAW_TO_WINDOW, TRUE,
SK_WGL_DOUBLE_BUFFER, TRUE,
SK_WGL_ACCELERATION, SK_WGL_FULL_ACCELERATION,
SK_WGL_SUPPORT_OPENGL, TRUE,
SK_WGL_COLOR_BITS, 24,
SK_WGL_ALPHA_BITS, 8,
SK_WGL_STENCIL_BITS, 8,
0, 0
};
float fAttrs[] = {0, 0};
if (msaaSampleCount > 0 &&
extensions.hasExtension(dc, "WGL_ARB_multisample")) {
static const int kIAttrsCount = SK_ARRAY_COUNT(iAttrs);
int msaaIAttrs[kIAttrsCount + 6];
memcpy(msaaIAttrs, iAttrs, sizeof(int) * kIAttrsCount);
SkASSERT(0 == msaaIAttrs[kIAttrsCount - 2] &&
0 == msaaIAttrs[kIAttrsCount - 1]);
msaaIAttrs[kIAttrsCount - 2] = SK_WGL_SAMPLE_BUFFERS;
msaaIAttrs[kIAttrsCount - 1] = TRUE;
msaaIAttrs[kIAttrsCount + 0] = SK_WGL_SAMPLES;
msaaIAttrs[kIAttrsCount + 1] = msaaSampleCount;
if (extensions.hasExtension(dc, "WGL_NV_multisample_coverage")) {
msaaIAttrs[kIAttrsCount + 2] = SK_WGL_COLOR_SAMPLES;
// We want the fewest number of color samples possible.
// Passing 0 gives only the formats where all samples are color
// samples.
msaaIAttrs[kIAttrsCount + 3] = 1;
msaaIAttrs[kIAttrsCount + 4] = 0;
msaaIAttrs[kIAttrsCount + 5] = 0;
} else {
msaaIAttrs[kIAttrsCount + 2] = 0;
msaaIAttrs[kIAttrsCount + 3] = 0;
}
unsigned int num;
int formats[64];
extensions.choosePixelFormat(dc, msaaIAttrs, fAttrs, 64, formats, &num);
num = min(num,64);
int formatToTry = extensions.selectFormat(formats,
num,
dc,
msaaSampleCount);
DescribePixelFormat(dc, formatToTry, sizeof(pfd), &pfd);
if (SetPixelFormat(dc, formatToTry, &pfd)) {
format = formatToTry;
}
}
if (0 == format) {
// Either MSAA wasn't requested or creation failed
unsigned int num;
extensions.choosePixelFormat(dc, iAttrs, fAttrs, 1, &format, &num);
DescribePixelFormat(dc, format, sizeof(pfd), &pfd);
SkDEBUGCODE(BOOL set =) SetPixelFormat(dc, format, &pfd);
SkASSERT(TRUE == set);
}