# HG changeset patch
# User Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
# Date 1413732146 -7200
# Node ID b7b4a234bf704983e5bca57bf94f2112f1531e72
# Parent  12756994a92cfae6a485f12d76ded0610fcd77c0
Fix legacy OpenGL support, and detect the absence of non-legacy context with libepoxy.

diff --git a/pytouhou/ui/opengl/backend.pyx b/pytouhou/ui/opengl/backend.pyx
--- a/pytouhou/ui/opengl/backend.pyx
+++ b/pytouhou/ui/opengl/backend.pyx
@@ -21,6 +21,8 @@ def init(options):
     working.
     '''
 
+    cdef str flavor
+
     global profile, major, minor, double_buffer, is_legacy, GameRenderer
 
     flavor = options['flavor']
@@ -37,23 +39,24 @@ def init(options):
     maybe_double_buffer = options['double-buffer']
     double_buffer = maybe_double_buffer if maybe_double_buffer is not None else -1
 
-    is_legacy = flavor == 'legacy'
-    is_gles = flavor == 'es'
+    is_legacy = flavor == 'legacy' or flavor == 'compatibility' and major < 2
 
     #TODO: check for framebuffer/renderbuffer support.
 
     from pytouhou.ui.opengl.gamerenderer import GameRenderer
 
 
-def discover_features():
+cdef void discover_features() except *:
     '''Discover which features are supported by our context.'''
 
-    global use_debug_group, use_vao, use_primitive_restart, use_pack_invert
+    global use_debug_group, use_vao, use_primitive_restart, use_framebuffer_blit, use_pack_invert
     global primitive_mode
     global shader_header
+    global is_legacy
 
     version = epoxy_gl_version()
     is_desktop = epoxy_is_desktop_gl()
+    is_legacy = is_desktop and version < 20
 
     use_debug_group = (is_desktop and version >= 43) or epoxy_has_gl_extension('GL_KHR_debug')
     use_vao = (is_desktop and version >= 30) or epoxy_has_gl_extension('GL_ARB_vertex_array_object')
@@ -63,22 +66,23 @@ def discover_features():
 
     primitive_mode = GL_TRIANGLE_STRIP if use_primitive_restart else GL_TRIANGLES
 
-    if is_desktop:
-        # gl_FragColor isn’t supported anymore starting with GLSL 4.2.
-        if version >= 42:
-            version = 41
-        try:
-            glsl_version = {20: 110, 21: 120, 30: 130, 31: 140, 32: 150}[version]
-        except KeyError:
-            assert version >= 33
-            glsl_version = version * 10
-        shader_header = ('#version %d\n\n' % glsl_version).encode()
-    else:
-        # The attribute keyword isn’t supported past GLSL ES 3.0.
-        if version >= 30:
-            version = 20
-        glsl_version = {20: '100', 30: '300 es'}[version]
-        shader_header = ('#version %s\n\nprecision highp float;\n\n' % glsl_version).encode()
+    if not is_legacy:
+        if is_desktop:
+            # gl_FragColor isn’t supported anymore starting with GLSL 4.2.
+            if version >= 42:
+                version = 41
+            try:
+                glsl_version = {20: 110, 21: 120, 30: 130, 31: 140, 32: 150}[version]
+            except KeyError:
+                assert version >= 33
+                glsl_version = version * 10
+            shader_header = ('#version %d\n\n' % glsl_version).encode()
+        else:
+            # The attribute keyword isn’t supported past GLSL ES 3.0.
+            if version >= 30:
+                version = 20
+            glsl_version = {20: '100', 30: '300 es'}[version]
+            shader_header = ('#version %s\n\nprecision highp float;\n\n' % glsl_version).encode()
 
 
 def create_window(title, x, y, width, height, swap_interval):
@@ -92,8 +96,6 @@ def create_window(title, x, y, width, he
         sdl.gl_set_attribute(sdl.GL_DOUBLEBUFFER, double_buffer)
 
     flags = sdl.WINDOW_SHOWN | sdl.WINDOW_OPENGL
-
-    #TODO: legacy can support one of the framebuffer extensions.
     if not is_legacy:
         flags |= sdl.WINDOW_RESIZABLE
 
@@ -102,6 +104,13 @@ def create_window(title, x, y, width, he
 
     discover_features()
 
+    #TODO: legacy could support one of the framebuffer extensions for resize,
+    # but for now set the window to a fixed size.
+    if is_legacy and flags & sdl.WINDOW_RESIZABLE:
+        flags &= ~sdl.WINDOW_RESIZABLE
+        window = Window(title, x, y, width, height, flags)
+        window.gl_create_context()
+
     if use_debug_group:
         glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, "OpenGL initialisation")
 
@@ -129,6 +138,8 @@ def create_window(title, x, y, width, he
         try:
             sdl.gl_set_swap_interval(swap_interval)
         except sdl.SDLError:
+            # The OpenGL context doesn’t support setting the swap interval,
+            # we’ll probably fallback to SDL_Delay-based clocking.
             pass
 
     return window