Mac: Add Cairo on Quartz support

This avoids the general hassles of OpenGL, which is deprecated on MacOS, and
Cairo apps look much nicer and more integrated this way.  As far as I can tell,
Cairo actually works best here out of all the platforms, the Windows and X11
backends aren't quite as smooth.

2 files changed, 113 insertions, 132 deletions

diff --git a/pugl/detail/cairo_gl.h b/pugl/detail/cairo_gl.h
deleted file mode 100644
index b6e8566..0000000
--- a/pugl/detail/cairo_gl.h
+++ /dev/null
@@ -1,103 +0,0 @@
-/*
-  Copyright 2016-2019 David Robillard <http://drobilla.net>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-/**
-   @file cairo_gl.h Generic Cairo to OpenGL drawing support.
-*/
-
-#include "pugl/gl.h"
-
-#include <cairo.h>
-#include <stdint.h>
-#include <stdlib.h>
-
-typedef struct {
-	unsigned texture_id;
-	uint8_t* buffer;
-} PuglCairoGL;
-
-static cairo_surface_t*
-pugl_cairo_gl_create(PuglCairoGL* ctx, int width, int height, int bpp)
-{
-	free(ctx->buffer);
-	ctx->buffer = (uint8_t*)calloc(bpp * width * height, sizeof(uint8_t));
-	if (!ctx->buffer) {
-		return NULL;
-	}
-
-	glDeleteTextures(1, &ctx->texture_id);
-	glGenTextures(1, &ctx->texture_id);
-	glBindTexture(GL_TEXTURE_RECTANGLE_ARB, ctx->texture_id);
-	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
-
-	return cairo_image_surface_create_for_data(
-		ctx->buffer, CAIRO_FORMAT_ARGB32, width, height, bpp * width);
-}
-
-static void
-pugl_cairo_gl_free(PuglCairoGL* ctx)
-{
-	free(ctx->buffer);
-	ctx->buffer = NULL;
-}
-
-static void
-pugl_cairo_gl_configure(PuglCairoGL* ctx, int width, int height)
-{
-	(void)ctx;
-	(void)width;
-	(void)height;
-	glDisable(GL_DEPTH_TEST);
-	glEnable(GL_TEXTURE_RECTANGLE_ARB);
-
-	glMatrixMode(GL_PROJECTION);
-	glLoadIdentity();
-	glOrtho(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
-}
-
-static void
-pugl_cairo_gl_draw(PuglCairoGL* ctx, int width, int height)
-{
-	glMatrixMode(GL_MODELVIEW);
-	glLoadIdentity();
-	glViewport(0, 0, width, height);
-
-	glPushMatrix();
-	glEnable(GL_TEXTURE_RECTANGLE_ARB);
-	glEnable(GL_TEXTURE_2D);
-
-	glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA8,
-	             width, height, 0,
-	             GL_BGRA, GL_UNSIGNED_BYTE, ctx->buffer);
-
-	glBegin(GL_QUADS);
-	glTexCoord2f(0.0f, (GLfloat)height);
-	glVertex2f(-1.0f, -1.0f);
-
-	glTexCoord2f((GLfloat)width, (GLfloat)height);
-	glVertex2f(1.0f, -1.0f);
-
-	glTexCoord2f((GLfloat)width, 0.0f);
-	glVertex2f(1.0f, 1.0f);
-
-	glTexCoord2f(0.0f, 0.0f);
-	glVertex2f(-1.0f, 1.0f);
-	glEnd();
-
-	glDisable(GL_TEXTURE_2D);
-	glDisable(GL_TEXTURE_RECTANGLE_ARB);
-	glPopMatrix();
-}
diff --git a/pugl/detail/mac.m b/pugl/detail/mac.m
index 6bbe4fb..2316ca3 100644
--- a/pugl/detail/mac.m
+++ b/pugl/detail/mac.m
@@ -27,8 +27,9 @@
 #include "pugl/pugl_gl_backend.h"
 
 #ifdef PUGL_HAVE_CAIRO
-#include "pugl/detail/cairo_gl.h"
 #include "pugl/pugl_cairo_backend.h"
+
+#include <cairo-quartz.h>
 #endif
 
 #import <Cocoa/Cocoa.h>
@@ -45,6 +46,7 @@ typedef NSUInteger NSWindowStyleMask;
 
 @class PuglWrapperView;
 @class PuglOpenGLView;
+@class PuglCairoView;
 
 struct PuglInternalsImpl {
 	NSApplication*   app;
@@ -53,11 +55,6 @@ struct PuglInternalsImpl {
 	id               window;
 	NSEvent*         nextEvent;
 	uint32_t         mods;
-#ifdef PUGL_HAVE_CAIRO
-	cairo_surface_t* surface;
-	cairo_t*         cr;
-	PuglCairoGL      cairo_gl;
-#endif
 };
 
 @interface PuglWindow : NSWindow
@@ -675,6 +672,59 @@ handleCrossing(PuglWrapperView* view, NSEvent* event, const PuglEventType type)
 
 @end
 
+@interface PuglCairoView : NSView
+{
+@public
+	PuglView*        puglview;
+	cairo_surface_t* surface;
+	cairo_t*         cr;
+}
+
+@end
+
+@implementation PuglCairoView
+
+- (id) initWithFrame:(NSRect)frame
+{
+	return (self = [super initWithFrame:frame]);
+}
+
+- (void) resizeWithOldSuperviewSize:(NSSize)oldSize
+{
+	[super resizeWithOldSuperviewSize:oldSize];
+
+	const NSRect bounds = [self bounds];
+	puglview->backend->resize(puglview, bounds.size.width, bounds.size.height);
+
+	const PuglEventConfigure ev =  {
+		PUGL_CONFIGURE,
+		0,
+		bounds.origin.x,
+		bounds.origin.y,
+		bounds.size.width,
+		bounds.size.height,
+	};
+
+	puglDispatchEvent(puglview, (const PuglEvent*)&ev);
+}
+
+- (void) drawRect:(NSRect)rect
+{
+	const PuglEventExpose ev =  {
+		PUGL_EXPOSE,
+		0,
+		rect.origin.x,
+		rect.origin.y,
+		rect.size.width,
+		rect.size.height,
+		0
+	};
+
+	puglDispatchEvent(puglview, (const PuglEvent*)&ev);
+}
+
+@end
+
 @interface PuglWindowDelegate : NSObject<NSWindowDelegate>
 {
 	PuglWindow* window;
@@ -1051,22 +1101,54 @@ const PuglBackend* puglGlBackend(void)
 static int
 puglMacCairoCreate(PuglView* view)
 {
-	return puglMacGlCreate(view);
+	PuglInternals* impl     = view->impl;
+	PuglCairoView* drawView = [PuglCairoView alloc];
+
+	drawView->puglview = view;
+	[drawView initWithFrame:NSMakeRect(0, 0, view->width, view->height)];
+	if (view->hints.resizable) {
+		[drawView setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
+	} else {
+		[drawView setAutoresizingMask:NSViewNotSizable];
+	}
+
+	impl->drawView = drawView;
+	return 0;
 }
 
 static int
 puglMacCairoDestroy(PuglView* view)
 {
-	pugl_cairo_gl_free(&view->impl->cairo_gl);
-	return puglMacGlDestroy(view);
+	PuglCairoView* const drawView = (PuglCairoView*)view->impl->drawView;
+
+	[drawView removeFromSuperview];
+	[drawView release];
+
+	view->impl->drawView = nil;
+	return 0;
 }
 
 static int
-puglMacCairoEnter(PuglView* view, bool PUGL_UNUSED(drawing))
+puglMacCairoEnter(PuglView* view, bool drawing)
 {
-	PuglOpenGLView* const drawView = (PuglOpenGLView*)view->impl->drawView;
+	PuglCairoView* const drawView = (PuglCairoView*)view->impl->drawView;
+	if (!drawing) {
+		return 0;
+	}
 
-	[[drawView openGLContext] makeCurrentContext];
+	// Get Quartz context and transform to Cairo coordinates (TL origin)
+	CGContextRef context = [[NSGraphicsContext currentContext] graphicsPort];
+	CGContextTranslateCTM(context, 0.0, view->height);
+	CGContextScaleCTM(context, 1.0, -1.0);
+
+	// Create a Cairo surface and context for drawing to Quartz
+	assert(!drawView->surface);
+	assert(!drawView->cr);
+
+	drawView->surface = cairo_quartz_surface_create_for_cg_context(
+		context, view->width, view->height);
+
+	drawView->cr = cairo_create(drawView->surface);
 
 	return 0;
 }
@@ -1074,37 +1156,39 @@ puglMacCairoEnter(PuglView* view, bool PUGL_UNUSED(drawing))
 static int
 puglMacCairoLeave(PuglView* view, bool drawing)
 {
-	PuglOpenGLView* const drawView = (PuglOpenGLView*)view->impl->drawView;
-
-	if (drawing) {
-		pugl_cairo_gl_draw(&view->impl->cairo_gl, view->width, view->height);
-		[[drawView openGLContext] flushBuffer];
+	PuglCairoView* const drawView = (PuglCairoView*)view->impl->drawView;
+	if (!drawing) {
+		return 0;
 	}
 
-	[NSOpenGLContext clearCurrentContext];
+	CGContextRef context = cairo_quartz_surface_get_cg_context(drawView->surface);
+
+	cairo_destroy(drawView->cr);
+	cairo_surface_destroy(drawView->surface);
+
+	CGContextFlush(context);
+
+	drawView->cr      = NULL;
+	drawView->surface = NULL;
 
 	return 0;
 }
 
-
 static int
-puglMacCairoResize(PuglView* view, int width, int height)
+puglMacCairoResize(PuglView* PUGL_UNUSED(view),
+                   int       PUGL_UNUSED(width),
+                   int       PUGL_UNUSED(height))
 {
-	PuglInternals* impl = view->impl;
-
-	cairo_surface_destroy(impl->surface);
-	cairo_destroy(impl->cr);
-	impl->surface = pugl_cairo_gl_create(&impl->cairo_gl, width, height, 4);
-	impl->cr = cairo_create(impl->surface);
-	pugl_cairo_gl_configure(&impl->cairo_gl, width, height);
-
+	// No need to resize, the surface is created for the drawing context
 	return 0;
 }
 
 static void*
 puglMacCairoGetContext(PuglView* view)
 {
-	return view->impl->cr;
+	PuglCairoView* const drawView = (PuglCairoView*)view->impl->drawView;
+
+	return drawView->cr;
 }
 
 const PuglBackend* puglCairoBackend(void)