OpenGL Widget: Proof of concept

android/pyproject.toml

@@ -90,6 +90,7 @@ Label = "toga_android.widgets.label:Label"
 MapView = "toga_android.widgets.mapview:MapView"
 MultilineTextInput = "toga_android.widgets.multilinetextinput:MultilineTextInput"
 NumberInput = "toga_android.widgets.numberinput:NumberInput"
+OpenGLView = "toga_android.widgets.openglview:OpenGLView"
 OptionContainer = "toga_android.widgets.optioncontainer:OptionContainer"
 PasswordInput = "toga_android.widgets.passwordinput:PasswordInput"
 ProgressBar = "toga_android.widgets.progressbar:ProgressBar"

android/src/toga_android/widgets/openglview.py

@@ -0,0 +1,67 @@
+from android.opengl import GLES20 as GL, GLSurfaceView
+from java import dynamic_proxy
+
+from toga.widgets.gl.openglcontext import OpenGLContext
+
+from .base import Widget
+
+
+class AndroidOpenGLContext(OpenGLContext):
+    """The implementation layer of a Qt OpenGL context."""
+
+    def clear_color(self, r: float, g: float, b: float, a: float):
+        GL.glClearColor(r, g, b, a)
+
+    def clear(self, mask: int):
+        GL.glClear(mask)
+
+    def create_shader(self, type: int):
+        return GL.glCreateShader(type)
+
+    def shader_source(self, shader: int, source: str):
+        GL.glShaderSource(shader, source)
+
+    def compile_shader(self, shader: int):
+        GL.glCompileShader(shader)
+
+    def delete_shader(self, shader):
+        GL.glDeleteShader(shader)
+
+    def create_program(self) -> int:
+        return GL.glCreateProgram()
+
+    def attach_shader(self, program: int, shader: int):
+        GL.glAttachShader(program, shader)
+
+    def link_program(self, program: int):
+        GL.glLinkProgram(program)
+
+    def delete_program(self, program):
+        GL.glDeleteProgram(program)
+
+
+class TogaGLRenderer(dynamic_proxy(GLSurfaceView.Renderer)):
+    def onSurfaceCreated(self, unused, config):
+        pass
+
+    def onDrawFrame(self, unused):
+        self._redraw()
+
+    def onSurfaceChanged(self, unused, width, height):
+        self._redraw()
+
+    def _redraw(self):
+        context = AndroidOpenGLContext()
+        self.interface.on_render(context)
+
+
+class OpenGLView(Widget):
+    def create(self):
+        self.native = GLSurfaceView(self._native_activity)
+        self.renderer = TogaGLRenderer()
+        self.renderer.interface = self.interface
+        self.native.setEGLContextClientVersion(2)
+        self.native.setRenderer(self.renderer)
+
+    def redraw(self):
+        self.native.invalidate()

cocoa/pyproject.toml

@@ -90,6 +90,7 @@ Label = "toga_cocoa.widgets.label:Label"
 MapView = "toga_cocoa.widgets.mapview:MapView"
 MultilineTextInput = "toga_cocoa.widgets.multilinetextinput:MultilineTextInput"
 NumberInput = "toga_cocoa.widgets.numberinput:NumberInput"
+OpenGLView = "toga_cocoa.widgets.openglview:OpenGLView"
 OptionContainer = "toga_cocoa.widgets.optioncontainer:OptionContainer"
 PasswordInput = "toga_cocoa.widgets.passwordinput:PasswordInput"
 ProgressBar = "toga_cocoa.widgets.progressbar:ProgressBar"

cocoa/src/toga_cocoa/libs/appkit.py

@@ -518,10 +518,21 @@ class NSLayoutPriority(Enum):
 NSOpenGLPFARemotePixelBuffer = 91  # can be used to render offline to a pbuffer
 NSOpenGLPFAAllowOfflineRenderers = 96  # allow use of offline renderers
 NSOpenGLPFAAcceleratedCompute = 97  # choose a hardware accelerated compute device
+NSOpenGLPFAOpenGLProfile = 99  # specify an OpenGL Profile to use
 NSOpenGLPFAVirtualScreenCount = 128  # number of virtual screens in this format
 
+NSOpenGLProfileVersionLegacy = 0x1000  # choose a Legacy/Pre-OpenGL 3.0 Implementation
+NSOpenGLProfileVersion3_2Core = 0x3200  # choose an OpenGL 3.2 Core Implementation
+NSOpenGLProfileVersion4_1Core = 0x4100  # choose an OpenGL 4.1 Core Implementation
+
 NSOpenGLCPSwapInterval = 222
 
+######################################################################
+# NSOpenGLView.h
+NSOpenGLView = ObjCClass("NSOpenGLView")
+NSOpenGLContext = ObjCClass("NSOpenGLContext")
+NSOpenGLPixelFormat = ObjCClass("NSOpenGLPixelFormat")
+
 ######################################################################
 # NSOpenPanel.h
 NSOpenPanel = ObjCClass("NSOpenPanel")

cocoa/src/toga_cocoa/widgets/openglview.py

@@ -0,0 +1,113 @@
+import ctypes
+from ctypes import c_float, cdll
+from ctypes.util import find_library
+
+from rubicon.objc import objc_method, objc_property
+from travertino.size import at_least
+
+from toga.widgets.gl.openglcontext import OpenGLContext
+from toga_cocoa.libs import (
+    NSOpenGLPFAAccelerated,
+    NSOpenGLPFAAccumSize,
+    NSOpenGLPFAAlphaSize,
+    NSOpenGLPFAColorSize,
+    NSOpenGLPFADepthSize,
+    NSOpenGLPFADoubleBuffer,
+    NSOpenGLPFANoRecovery,
+    NSOpenGLPFAStencilSize,
+    NSOpenGLPFAWindow,
+    NSOpenGLPixelFormat,
+    NSOpenGLView,
+    NSRect,
+)
+
+from .base import Widget
+
+# possibly use PyOpenGL instead?
+GL = cdll.LoadLibrary(find_library("OpenGL"))
+
+
+class CocoaOpenGLContext(OpenGLContext):
+    def clear_color(self, r: float, g: float, b: float, a: float):
+        GL.glClearColor(c_float(r), c_float(g), c_float(b), c_float(a))
+
+    def clear(self, mask: int):
+        GL.glClear(mask)
+
+    def create_shader(self, type: int):
+        return GL.glCreateShader(type)
+
+    def shader_source(self, shader: int, source: str):
+        GL.glShaderSource(shader, source)
+
+    def compile_shader(self, shader: int):
+        GL.glCompileShader(shader)
+
+    def delete_shader(self, shader: int):
+        GL.glDeleteShader(shader)
+
+    def create_program(self) -> int:
+        return GL.glCreateProgram()
+
+    def attach_shader(self, program: int, shader: int):
+        GL.glAttachShader(program, shader)
+
+    def link_program(self, program: int):
+        GL.glLinkProgram(program)
+
+    def delete_program(self, program):
+        GL.glDeleteProgram(program)
+
+
+class TogaOpenGLView(NSOpenGLView):
+    interface = objc_property(object, weak=True)
+    impl = objc_property(object, weak=True)
+
+    @objc_method
+    def drawRect_(self, rect: NSRect) -> None:
+        self.openGLContext.makeCurrentContext()
+        context = self.openGLContext
+        GL.glViewport(0, 0, int(rect.size.width), int(rect.size.height))
+        self.interface.on_render(CocoaOpenGLContext())
+        context.flushBuffer()
+
+    @objc_method
+    def initWithFrame_(self, frame: NSRect):
+        a = (
+            NSOpenGLPFANoRecovery,
+            NSOpenGLPFAWindow,
+            NSOpenGLPFAAccelerated,
+            NSOpenGLPFADoubleBuffer,
+            NSOpenGLPFAColorSize,
+            24,
+            NSOpenGLPFAAlphaSize,
+            8,
+            NSOpenGLPFADepthSize,
+            24,
+            NSOpenGLPFAStencilSize,
+            8,
+            NSOpenGLPFAAccumSize,
+            0,
+        )
+        attributes = (ctypes.c_uint32 * len(a))(*a)
+        pixel_format = NSOpenGLPixelFormat.alloc().initWithAttributes_(attributes)
+        return self.initWithFrame_pixelFormat_(frame, pixel_format)
+
+
+class OpenGLView(Widget):
+    def create(self):
+        self.native = TogaOpenGLView.alloc().init()
+        self.native.interface = self.interface
+        self.native.impl = self
+
+        # Add the layout constraints
+        self.add_constraints()
+
+    def redraw(self):
+        self.native.needsDisplay = True
+
+    # Rehint
+    def rehint(self):
+        fitting_size = self.native.fittingSize()
+        self.interface.intrinsic.height = at_least(fitting_size.height)
+        self.interface.intrinsic.width = at_least(fitting_size.width)

core/src/toga/__init__.pyi

@@ -47,6 +47,7 @@ from toga.widgets.multilinetextinput import MultilineTextInput as MultilineTextI
 from toga.widgets.numberinput import NumberInput as NumberInput
 from toga.widgets.optioncontainer import OptionContainer as OptionContainer
 from toga.widgets.optioncontainer import OptionItem as OptionItem
+from toga.widgets.gl.openglview import OpenGLView as OpenGLView
 from toga.widgets.passwordinput import PasswordInput as PasswordInput
 from toga.widgets.progressbar import ProgressBar as ProgressBar
 from toga.widgets.box import Row as Row