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.

8 files changed, 30 insertions, 14 deletions

diff --git a/bindings/cpp/include/pugl/pugl.hpp b/bindings/cpp/include/pugl/pugl.hpp
index 5f939d5..4fe7244 100644
--- a/bindings/cpp/include/pugl/pugl.hpp
+++ b/bindings/cpp/include/pugl/pugl.hpp
@@ -352,6 +352,7 @@ enum class ViewHint {
   alphaBits,           ///< @copydoc PUGL_ALPHA_BITS
   depthBits,           ///< @copydoc PUGL_DEPTH_BITS
   stencilBits,         ///< @copydoc PUGL_STENCIL_BITS
+  sampleBuffers,       ///< @copydoc PUGL_SAMPLE_BUFFERS
   samples,             ///< @copydoc PUGL_SAMPLES
   doubleBuffer,        ///< @copydoc PUGL_DOUBLE_BUFFER
   swapInterval,        ///< @copydoc PUGL_SWAP_INTERVAL
diff --git a/include/pugl/pugl.h b/include/pugl/pugl.h
index 338aa4d..0e97f91 100644
--- a/include/pugl/pugl.h
+++ b/include/pugl/pugl.h
@@ -882,6 +882,7 @@ typedef enum {
   PUGL_ALPHA_BITS,            ///< Number of bits for alpha channel
   PUGL_DEPTH_BITS,            ///< Number of bits for depth buffer
   PUGL_STENCIL_BITS,          ///< Number of bits for stencil buffer
+  PUGL_SAMPLE_BUFFERS,        ///< Number of sample buffers (AA)
   PUGL_SAMPLES,               ///< Number of samples per pixel (AA)
   PUGL_DOUBLE_BUFFER,         ///< True if double buffering should be used
   PUGL_SWAP_INTERVAL,         ///< Number of frames between buffer swaps
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);
diff --git a/test/test_gl_hints.c b/test/test_gl_hints.c
index 7e91035..64c7342 100644
--- a/test/test_gl_hints.c
+++ b/test/test_gl_hints.c
@@ -55,6 +55,7 @@ main(void)
   assert(!puglSetViewHint(view, PUGL_ALPHA_BITS, PUGL_DONT_CARE));
   assert(!puglSetViewHint(view, PUGL_DEPTH_BITS, PUGL_DONT_CARE));
   assert(!puglSetViewHint(view, PUGL_STENCIL_BITS, PUGL_DONT_CARE));
+  assert(!puglSetViewHint(view, PUGL_SAMPLE_BUFFERS, PUGL_DONT_CARE));
   assert(!puglSetViewHint(view, PUGL_SAMPLES, PUGL_DONT_CARE));
   assert(!puglSetViewHint(view, PUGL_DOUBLE_BUFFER, PUGL_DONT_CARE));
   assert(!puglSetViewHint(view, PUGL_REFRESH_RATE, PUGL_DONT_CARE));
@@ -74,6 +75,7 @@ main(void)
   assert(puglGetViewHint(view, PUGL_ALPHA_BITS) != PUGL_DONT_CARE);
   assert(puglGetViewHint(view, PUGL_DEPTH_BITS) != PUGL_DONT_CARE);
   assert(puglGetViewHint(view, PUGL_STENCIL_BITS) != PUGL_DONT_CARE);
+  assert(puglGetViewHint(view, PUGL_SAMPLE_BUFFERS) != PUGL_DONT_CARE);
   assert(puglGetViewHint(view, PUGL_SAMPLES) != PUGL_DONT_CARE);
   assert(puglGetViewHint(view, PUGL_DOUBLE_BUFFER) != PUGL_DONT_CARE);
   assert(puglGetViewHint(view, PUGL_SWAP_INTERVAL) != PUGL_DONT_CARE);
diff --git a/test/test_utils.h b/test/test_utils.h
index 85276fb..db3485b 100644
--- a/test/test_utils.h
+++ b/test/test_utils.h
@@ -275,6 +275,8 @@ puglViewHintString(const PuglViewHint hint)
     return "Depth bits";
   case PUGL_STENCIL_BITS:
     return "Stencil bits";
+  case PUGL_SAMPLE_BUFFERS:
+    return "Sample buffers";
   case PUGL_SAMPLES:
     return "Samples";
   case PUGL_DOUBLE_BUFFER: