Add PUGL_SAMPLE_BUFFERS hint

Towards a more direct and explicit mapping to platform hints, and more
consistent behaviour across platforms.  OpenGL applications are generally
expected to be explicit about hints like this.

4 files changed, 24 insertions, 14 deletions

diff --git a/src/common.c b/src/common.c
index 9bb2d2e..90a75cf 100644
--- a/src/common.c
+++ b/src/common.c
@@ -101,6 +101,7 @@ puglSetDefaultHints(PuglHints hints)
   hints[PUGL_ALPHA_BITS]            = 8;
   hints[PUGL_DEPTH_BITS]            = 0;
   hints[PUGL_STENCIL_BITS]          = 0;
+  hints[PUGL_SAMPLE_BUFFERS]        = PUGL_DONT_CARE;
   hints[PUGL_SAMPLES]               = 0;
   hints[PUGL_DOUBLE_BUFFER]         = PUGL_TRUE;
   hints[PUGL_SWAP_INTERVAL]         = PUGL_DONT_CARE;
diff --git a/src/mac_gl.m b/src/mac_gl.m
index 53daf97..69acde7 100644
--- a/src/mac_gl.m
+++ b/src/mac_gl.m
@@ -40,6 +40,9 @@
   if (puglview->hints[PUGL_SAMPLES] == PUGL_DONT_CARE) {
     puglview->hints[PUGL_SAMPLES] = 1;
   }
+  if (puglview->hints[PUGL_SAMPLE_BUFFERS] == PUGL_DONT_CARE) {
+    puglview->hints[PUGL_SAMPLE_BUFFERS] = puglview->hints[PUGL_SAMPLES] > 0;
+  }
   if (puglview->hints[PUGL_DOUBLE_BUFFER] == PUGL_DONT_CARE) {
     puglview->hints[PUGL_DOUBLE_BUFFER] = 1;
   }
diff --git a/src/win_gl.c b/src/win_gl.c
index 44795f5..9850b6f 100644
--- a/src/win_gl.c
+++ b/src/win_gl.c
@@ -103,7 +103,10 @@ puglWinGlConfigure(PuglView* view)
     view->hints[PUGL_STENCIL_BITS] = 0;
   }
   if (view->hints[PUGL_SAMPLES] == PUGL_DONT_CARE) {
-    view->hints[PUGL_SAMPLES] = 1;
+    view->hints[PUGL_SAMPLES] = 0;
+  }
+  if (view->hints[PUGL_SAMPLE_BUFFERS] == PUGL_DONT_CARE) {
+    view->hints[PUGL_SAMPLE_BUFFERS] = view->hints[PUGL_SAMPLES] > 0;
   }
   if (view->hints[PUGL_DOUBLE_BUFFER] == PUGL_DONT_CARE) {
     view->hints[PUGL_DOUBLE_BUFFER] = 1;
@@ -119,7 +122,7 @@ puglWinGlConfigure(PuglView* view)
     WGL_SUPPORT_OPENGL_ARB, GL_TRUE,
     WGL_DOUBLE_BUFFER_ARB,  view->hints[PUGL_DOUBLE_BUFFER],
     WGL_PIXEL_TYPE_ARB,     WGL_TYPE_RGBA_ARB,
-    WGL_SAMPLE_BUFFERS_ARB, view->hints[PUGL_SAMPLES] ? 1 : 0,
+    WGL_SAMPLE_BUFFERS_ARB, view->hints[PUGL_SAMPLE_BUFFERS],
     WGL_SAMPLES_ARB,        view->hints[PUGL_SAMPLES],
     WGL_RED_BITS_ARB,       view->hints[PUGL_RED_BITS],
     WGL_GREEN_BITS_ARB,     view->hints[PUGL_GREEN_BITS],
diff --git a/src/x11_gl.c b/src/x11_gl.c
index 2e15092..f1dc56b 100644
--- a/src/x11_gl.c
+++ b/src/x11_gl.c
@@ -52,18 +52,19 @@ puglX11GlConfigure(PuglView* view)
 
   // clang-format off
   const int attrs[] = {
-    GLX_X_RENDERABLE,  True,
-    GLX_X_VISUAL_TYPE, GLX_TRUE_COLOR,
-    GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT,
-    GLX_RENDER_TYPE,   GLX_RGBA_BIT,
-    GLX_SAMPLES,       puglX11GlHintValue(view->hints[PUGL_SAMPLES]),
-    GLX_RED_SIZE,      puglX11GlHintValue(view->hints[PUGL_RED_BITS]),
-    GLX_GREEN_SIZE,    puglX11GlHintValue(view->hints[PUGL_GREEN_BITS]),
-    GLX_BLUE_SIZE,     puglX11GlHintValue(view->hints[PUGL_BLUE_BITS]),
-    GLX_ALPHA_SIZE,    puglX11GlHintValue(view->hints[PUGL_ALPHA_BITS]),
-    GLX_DEPTH_SIZE,    puglX11GlHintValue(view->hints[PUGL_DEPTH_BITS]),
-    GLX_STENCIL_SIZE,  puglX11GlHintValue(view->hints[PUGL_STENCIL_BITS]),
-    GLX_DOUBLEBUFFER,  puglX11GlHintValue(view->hints[PUGL_DOUBLE_BUFFER]),
+    GLX_X_RENDERABLE,   True,
+    GLX_X_VISUAL_TYPE,  GLX_TRUE_COLOR,
+    GLX_DRAWABLE_TYPE,  GLX_WINDOW_BIT,
+    GLX_RENDER_TYPE,    GLX_RGBA_BIT,
+    GLX_SAMPLE_BUFFERS, puglX11GlHintValue(view->hints[PUGL_SAMPLE_BUFFERS]),
+    GLX_SAMPLES,        puglX11GlHintValue(view->hints[PUGL_SAMPLES]),
+    GLX_RED_SIZE,       puglX11GlHintValue(view->hints[PUGL_RED_BITS]),
+    GLX_GREEN_SIZE,     puglX11GlHintValue(view->hints[PUGL_GREEN_BITS]),
+    GLX_BLUE_SIZE,      puglX11GlHintValue(view->hints[PUGL_BLUE_BITS]),
+    GLX_ALPHA_SIZE,     puglX11GlHintValue(view->hints[PUGL_ALPHA_BITS]),
+    GLX_DEPTH_SIZE,     puglX11GlHintValue(view->hints[PUGL_DEPTH_BITS]),
+    GLX_STENCIL_SIZE,   puglX11GlHintValue(view->hints[PUGL_STENCIL_BITS]),
+    GLX_DOUBLEBUFFER,   puglX11GlHintValue(view->hints[PUGL_DOUBLE_BUFFER]),
     None
   };
   // clang-format on
@@ -89,6 +90,8 @@ puglX11GlConfigure(PuglView* view)
     puglX11GlGetAttrib(display, fbc[0], GLX_DEPTH_SIZE);
   view->hints[PUGL_STENCIL_BITS] =
     puglX11GlGetAttrib(display, fbc[0], GLX_STENCIL_SIZE);
+  view->hints[PUGL_SAMPLE_BUFFERS] =
+    puglX11GlGetAttrib(display, fbc[0], GLX_SAMPLE_BUFFERS);
   view->hints[PUGL_SAMPLES] = puglX11GlGetAttrib(display, fbc[0], GLX_SAMPLES);
   view->hints[PUGL_DOUBLE_BUFFER] =
     puglX11GlGetAttrib(display, fbc[0], GLX_DOUBLEBUFFER);