Legacy OpenGL example is broken

[GrimMaple]

Currenty it draws just some small bit on the bottom of the window.

[Superbelko]

Oh, I think it was like that for eternity. IIRC in platform code it basically sticks to whatever API is available and won't ever try to recreate anything.

But if you say that there is small bit of actual drawing maybe it is just glViewport or projection/model matrices or something was accidentally removed somewhere?

[GrimMaple]

I recently rewritten the window creation code to create a compatibility GL context. Which doesn't seem to work, unfortunately :(
Creating an "old" version context (eg 2.0) also doesn't bring much joy to the world, as DlangUI itself requires modern API to draw itself. As a result, I'm a bit stuck. Either have to implement the pipeline for fixed API as well, or have to figure out compatibility context :/

[Superbelko]

I recently rewritten the window creation code to create a compatibility GL context.

You mean core (aka forward compatible) context? I have implemented that locally for testing, Windows only though, can add PR for that, basically 20-30 lines of code including declarations and few changes to be able to reset internal stuff.

[GrimMaple]

I recently rewritten the window creation code to create a compatibility GL context.

You mean core (aka forward compatible) context? I have implemented that locally for testing, Windows only though, can add PR for that, basically 20-30 lines of code including declarations and few changes to be able to reset internal stuff.

There's no need to, as I already implemented it in c9ccaad . Multisampling is done the same way as getting compatibility GL context. I just need to figure out why said compatibility doesn't really work :)

[Superbelko]

I recently rewritten the window creation code to create a compatibility GL context.

You mean core (aka forward compatible) context? I have implemented that locally for testing, Windows only though, can add PR for that, basically 20-30 lines of code including declarations and few changes to be able to reset internal stuff.

There's no need to, as I already implemented it in c9ccaad . Multisampling is done the same way as getting compatibility GL context. I just need to figure out why said compatibility doesn't really work :)

Umm, where do you call wglCreateContextAttribsARB?
It is required for core contexts as by default it sticks to legacy fixed-functions pipeline compatible contexts.

Or I am thinking about different thing here?

[GrimMaple]

I recently rewritten the window creation code to create a compatibility GL context.

You mean core (aka forward compatible) context? I have implemented that locally for testing, Windows only though, can add PR for that, basically 20-30 lines of code including declarations and few changes to be able to reset internal stuff.

There's no need to, as I already implemented it in c9ccaad . Multisampling is done the same way as getting compatibility GL context. I just need to figure out why said compatibility doesn't really work :)

Umm, where do you call wglCreateContextAttribsARB? It is required for core contexts as by default it sticks to legacy fixed-functions pipeline compatible contexts.

Or I am thinking about different thing here?

I think that might be it, actually. I used wglChoosePixelFormatARB, but for context creation, I used the non-extension funtion. I'll test it when I get the chance, thank you!

[Superbelko]

Here is my local stuff I did for testing, patch file for reference.

Windows only, other platforms does something similar except using their own variants like glXCreateContextAttribsARB for Linux and whatever it is on Mac OS.

Basically my intent was to be able to use it in a game or at least use it as editor UI

 src/dlangui/graphics/glsupport.d       |  7 +++++
 src/dlangui/platforms/windows/winapp.d | 48 ++++++++++++++++++++++++++++++----
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/src/dlangui/graphics/glsupport.d b/src/dlangui/graphics/glsupport.d
index e71f0f47..48cb32b3 100644
--- a/src/dlangui/graphics/glsupport.d
+++ b/src/dlangui/graphics/glsupport.d
@@ -662,6 +662,13 @@ private __gshared GLSupport _glSupport;
 
 __gshared bool glNoContext;
 
+void resetGlSupport()
+{
+    if (_glSupport)
+        destroy(_glSupport);
+    _glSupport = null;
+}
+
 /// initialize OpenGL support helper (call when current OpenGL context is initialized)
 bool initGLSupport(bool legacy = false) {
     import dlangui.platforms.common.platform : setOpenglEnabled;
diff --git a/src/dlangui/platforms/windows/winapp.d b/src/dlangui/platforms/windows/winapp.d
index d5af722e..3e04c763 100644
--- a/src/dlangui/platforms/windows/winapp.d
+++ b/src/dlangui/platforms/windows/winapp.d
@@ -45,6 +45,20 @@ import dlangui.core.files;
 
 static if (ENABLE_OPENGL) {
     import dlangui.graphics.glsupport;
+
+    alias PFNWGLSWAPINTERVALEXTPROC = extern(C) void function(GLint);
+    PFNWGLSWAPINTERVALEXTPROC wglSwapIntervalEXT;
+
+    // context creation
+
+    alias PFN_wglCreateContextAttribsARB = extern(C) HGLRC function(HDC hdc, HGLRC hShareContext, const int *attribList);
+    PFN_wglCreateContextAttribsARB wglCreateContextAttribsARB;
+
+    enum WGL_CONTEXT_MAJOR_VERSION_ARB =             0x2091;
+    enum WGL_CONTEXT_MINOR_VERSION_ARB =             0x2092;
+    enum WGL_CONTEXT_PROFILE_MASK_ARB =              0x9126;
+
+    enum WGL_CONTEXT_CORE_PROFILE_BIT_ARB =          0x00000001;
 }
 
 // specify debug=DebugMouseEvents for logging mouse handling
@@ -72,14 +86,14 @@ static if (ENABLE_OPENGL) {
                 PFD_DRAW_TO_WINDOW |
                 PFD_DOUBLEBUFFER,               /* support double-buffering */
             PFD_TYPE_RGBA,                  /* color type */
-            16,                             /* prefered color depth */
+            32,                             /* prefered color depth */
             0, 0, 0, 0, 0, 0,               /* color bits (ignored) */
             0,                              /* no alpha buffer */
             0,                              /* alpha bits (ignored) */
             0,                              /* no accumulation buffer */
             0, 0, 0, 0,                     /* accum bits (ignored) */
-            16,                             /* depth buffer */
-            0,                              /* no stencil buffer */
+            24,                             /* depth buffer */
+            8,                              /* no stencil buffer */
             0,                              /* no auxiliary buffers */
             0,                              /* main layer PFD_MAIN_PLANE */
             0,                              /* reserved */
@@ -184,6 +198,30 @@ static if (ENABLE_OPENGL) {
                 if (_hGLRC) {
                     bind(hDC);
                     bool initialized = initGLSupport(Platform.instance.GLVersionMajor < 3);
+                    
+                    wglSwapIntervalEXT = cast(typeof(wglSwapIntervalEXT)) wglGetProcAddress("wglSwapIntervalEXT");
+                    wglCreateContextAttribsARB = cast(PFN_wglCreateContextAttribsARB) wglGetProcAddress("wglCreateContextAttribsARB");
+
+                    // Specify that we want to create an OpenGL 3.3 core profile context
+                    int[] gl33_attribs = [
+                        WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
+                        WGL_CONTEXT_MINOR_VERSION_ARB, 3,
+                        WGL_CONTEXT_PROFILE_MASK_ARB,  WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
+                        0,
+                    ];
+
+                    // try to create core context if possible
+                    if (auto coreGLRC = wglCreateContextAttribsARB(hDC, null, gl33_attribs.ptr)) {
+                        resetGlSupport();
+                        wglMakeCurrent(hDC, null);
+                        wglDeleteContext(_hGLRC);
+                        _hGLRC = coreGLRC;
+                        wglMakeCurrent(hDC, _hGLRC);
+                        initialized = initGLSupport();
+                    }
+
+                    if (wglSwapIntervalEXT) 
+                        wglSwapIntervalEXT(0); // no vsync
                     unbind(hDC);
                     if (!initialized) {
                         uninit();
@@ -340,9 +378,9 @@ class Win32Window : Window {
             float g = ((_backgroundColor >> 8) & 255) / 255.0f;
             float b = ((_backgroundColor >> 0) & 255) / 255.0f;
             glClearColor(r, g, b, a);
-            glClear(GL_COLOR_BUFFER_BIT);
+            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);           
 
-            GLDrawBuf buf = new GLDrawBuf(_dx, _dy, false);
+            scope GLDrawBuf buf = new GLDrawBuf(_dx, _dy, false);
             buf.beforeDrawing();
             static if (false) {
                 // for testing for render