Add support for Cairo on GL

4 files changed, 201 insertions, 31 deletions

diff --git a/pugl/cairo_gl.h b/pugl/cairo_gl.h
new file mode 100644
index 0000000..a558b42
--- /dev/null
+++ b/pugl/cairo_gl.h
@@ -0,0 +1,102 @@
+/*
+  Copyright 2016 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.
+*/
+
+#if defined(PUGL_HAVE_GL) && defined(PUGL_HAVE_CAIRO)
+
+#include <stdint.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) {
+		fprintf(stderr, "failed to allocate surface buffer\n");
+		return NULL;
+	}
+
+	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)
+{
+	glDisable(GL_DEPTH_TEST);
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	glEnable(GL_TEXTURE_RECTANGLE_ARB);
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glOrtho(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
+
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	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);
+}
+
+static void
+pugl_cairo_gl_draw(PuglCairoGL* ctx, int width, int height)
+{
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glViewport(0, 0, width, height);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	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();
+}
+
+#endif
diff --git a/pugl/common.h b/pugl/common.h
index 54ec6ef..3abab82 100644
--- a/pugl/common.h
+++ b/pugl/common.h
@@ -1,5 +1,5 @@
 /*
-  Copyright 2014 David Robillard <http://drobilla.net>
+  Copyright 2014-2016 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
@@ -56,8 +56,9 @@ typedef enum {
    Drawing context type.
 */
 typedef enum {
-	PUGL_GL,
-	PUGL_CAIRO
+	PUGL_GL       = 0x1,
+	PUGL_CAIRO    = 0x2,
+	PUGL_CAIRO_GL = 0x3
 } PuglContextType;
 
 /**
diff --git a/pugl/pugl_internal.h b/pugl/pugl_internal.h
index 1238ebc..778ff1f 100644
--- a/pugl/pugl_internal.h
+++ b/pugl/pugl_internal.h
@@ -1,5 +1,5 @@
 /*
-  Copyright 2012-2015 David Robillard <http://drobilla.net>
+  Copyright 2012-2016 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
@@ -86,9 +86,10 @@ puglInit(int* pargc, char** argv)
 		return NULL;
 	}
 
-	view->impl   = impl;
-	view->width  = 640;
-	view->height = 480;
+	view->ctx_type = PUGL_GL;
+	view->impl     = impl;
+	view->width    = 640;
+	view->height   = 480;
 
 	return view;
 }
diff --git a/pugl/pugl_x11.c b/pugl/pugl_x11.c
index 94827f3..e6d240c 100644
--- a/pugl/pugl_x11.c
+++ b/pugl/pugl_x11.c
@@ -1,5 +1,5 @@
 /*
-  Copyright 2012-2015 David Robillard <http://drobilla.net>
+  Copyright 2012-2016 David Robillard <http://drobilla.net>
   Copyright 2013 Robin Gareus <robin@gareus.org>
   Copyright 2011-2012 Ben Loftis, Harrison Consoles
 
@@ -40,6 +40,7 @@
 #endif
 
 #include "pugl/event.h"
+#include "pugl/cairo_gl.h"
 #include "pugl/pugl_internal.h"
 
 #ifndef MIN
@@ -93,6 +94,9 @@ struct PuglInternalsImpl {
 	GLXContext       ctx;
 	int              doubleBuffered;
 #endif
+#if defined(PUGL_HAVE_CAIRO) && defined(PUGL_HAVE_GL)
+	PuglCairoGL      cairo_gl;
+#endif
 };
 
 PuglInternals*
@@ -108,7 +112,7 @@ getVisual(PuglView* view)
 	XVisualInfo*         vi   = NULL;
 
 #ifdef PUGL_HAVE_GL
-	if (view->ctx_type == PUGL_GL) {
+	if (view->ctx_type & PUGL_GL) {
 		for (int* attr = *attrLists; !vi && *attr; ++attr) {
 			vi = glXChooseVisual(impl->display, impl->screen, attr);
 		}
@@ -126,38 +130,78 @@ getVisual(PuglView* view)
 	return vi;
 }
 
-static void
+#ifdef PUGL_HAVE_CAIRO
+static int
+createCairoContext(PuglView* view)
+{
+	PuglInternals* const impl = view->impl;
+
+	if (impl->cr) {
+		cairo_destroy(impl->cr);
+	}
+
+	impl->cr = cairo_create(impl->surface);
+	return cairo_status(impl->cr);
+}
+#endif
+
+static bool
 createContext(PuglView* view, XVisualInfo* vi)
 {
 	PuglInternals* const impl = view->impl;
 
 #ifdef PUGL_HAVE_GL
-	if (view->ctx_type == PUGL_GL) {
+	if (view->ctx_type & PUGL_GL) {
 		impl->ctx = glXCreateContext(impl->display, vi, 0, GL_TRUE);
 		glXGetConfig(impl->display, vi, GLX_DOUBLEBUFFER, &impl->doubleBuffered);
 	}
 #endif
 #ifdef PUGL_HAVE_CAIRO
 	if (view->ctx_type == PUGL_CAIRO) {
-		view->impl->surface = cairo_xlib_surface_create(
+		impl->surface = cairo_xlib_surface_create(
 			impl->display, impl->win, vi->visual, view->width, view->height);
-		if (!(impl->cr = cairo_create(view->impl->surface))) {
-			fprintf(stderr, "failed to create cairo context\n");
+	}
+#endif
+#if defined(PUGL_HAVE_GL) && defined(PUGL_HAVE_CAIRO)
+	if (view->ctx_type == PUGL_CAIRO_GL) {
+		impl->surface = pugl_cairo_gl_create(
+			&impl->cairo_gl, view->width, view->height, 4);
+	}
+#endif
+
+#ifdef PUGL_HAVE_CAIRO
+	if (view->ctx_type & PUGL_CAIRO) {
+		if (cairo_surface_status(impl->surface) != CAIRO_STATUS_SUCCESS) {
+			fprintf(stderr, "error: failed to create cairo surface\n");
+			return false;
+		}
+
+		if (createCairoContext(view) != CAIRO_STATUS_SUCCESS) {
+			cairo_surface_destroy(impl->surface);
+			fprintf(stderr, "error: failed to create cairo context\n");
+			return false;
 		}
 	}
 #endif
+
+	return true;
 }
 
 static void
 destroyContext(PuglView* view)
 {
+#if defined(PUGL_HAVE_CAIRO) && defined(PUGL_HAVE_GL)
+	if (view->ctx_type == PUGL_CAIRO_GL) {
+		pugl_cairo_gl_free(&view->impl->cairo_gl);
+	}
+#endif
 #ifdef PUGL_HAVE_GL
-	if (view->ctx_type == PUGL_GL) {
+	if (view->ctx_type & PUGL_GL) {
 		glXDestroyContext(view->impl->display, view->impl->ctx);
 	}
 #endif
 #ifdef PUGL_HAVE_CAIRO
-	if (view->ctx_type == PUGL_CAIRO) {
+	if (view->ctx_type & PUGL_CAIRO) {
 		cairo_destroy(view->impl->cr);
 		cairo_surface_destroy(view->impl->surface);
 	}
@@ -168,12 +212,12 @@ void
 puglEnterContext(PuglView* view)
 {
 #ifdef PUGL_HAVE_GL
-	if (view->ctx_type == PUGL_GL) {
+	if (view->ctx_type & PUGL_GL) {
 		glXMakeCurrent(view->impl->display, view->impl->win, view->impl->ctx);
 	}
 #endif
 #ifdef PUGL_HAVE_CAIRO
-	if (view->ctx_type == PUGL_CAIRO) {
+	if (view->ctx_type & PUGL_CAIRO) {
 		cairo_set_source_rgb(view->impl->cr, 0, 0, 0);
 		cairo_paint(view->impl->cr);
 	}
@@ -184,12 +228,20 @@ void
 puglLeaveContext(PuglView* view, bool flush)
 {
 #ifdef PUGL_HAVE_GL
-	if (view->ctx_type == PUGL_GL && flush) {
+	if (flush && view->ctx_type & PUGL_GL) {
+#ifdef PUGL_HAVE_CAIRO
+		if (view->ctx_type == PUGL_CAIRO_GL) {
+			pugl_cairo_gl_draw(&view->impl->cairo_gl, view->width, view->height);
+		}
+#endif
+
 		glFlush();
 		if (view->impl->doubleBuffered) {
 			glXSwapBuffers(view->impl->display, view->impl->win);
 		}
 	}
+
+	glXMakeCurrent(view->impl->display, None, NULL);
 #endif
 }
 
@@ -227,7 +279,9 @@ puglCreateWindow(PuglView* view, const char* title)
 		0, 0, view->width, view->height, 0, vi->depth, InputOutput, vi->visual,
 		CWColormap | CWEventMask, &attr);
 
-	createContext(view, vi);
+	if (!createContext(view, vi)) {
+		return 2;
+	}
 
 	XSizeHints sizeHints;
 	memset(&sizeHints, 0, sizeof(sizeHints));
@@ -304,17 +358,14 @@ puglHideWindow(PuglView* view)
 void
 puglDestroy(PuglView* view)
 {
-	if (!view) {
-		return;
+	if (view) {
+		destroyContext(view);
+		XDestroyWindow(view->impl->display, view->impl->win);
+		XCloseDisplay(view->impl->display);
+		free(view->windowClass);
+		free(view->impl);
+		free(view);
 	}
-
-	destroyContext(view);
-	XDestroyWindow(view->impl->display, view->impl->win);
-	XCloseDisplay(view->impl->display);
-	free(view->windowClass);
-	free(view->impl);
-	free(view);
-	view = NULL;
 }
 
 static PuglKey
@@ -603,6 +654,21 @@ puglProcessEvents(PuglView* view)
 			                            config_event.configure.width,
 			                            config_event.configure.height);
 		}
+#ifdef PUGL_HAVE_GL
+		if (view->ctx_type == PUGL_CAIRO_GL) {
+			view->redisplay = true;
+			cairo_surface_destroy(view->impl->surface);
+			view->impl->surface = pugl_cairo_gl_create(
+				&view->impl->cairo_gl,
+				config_event.configure.width,
+				config_event.configure.height,
+				4);
+			pugl_cairo_gl_configure(&view->impl->cairo_gl,
+			                        config_event.configure.width,
+			                        config_event.configure.height);
+			createCairoContext(view);
+		}
+#endif
 #endif
 		puglDispatchEvent(view, (const PuglEvent*)&config_event);
 	}
@@ -640,7 +706,7 @@ void*
 puglGetContext(PuglView* view)
 {
 #ifdef PUGL_HAVE_CAIRO
-	if (view->ctx_type == PUGL_CAIRO) {
+	if (view->ctx_type & PUGL_CAIRO) {
 		return view->impl->cr;
 	}
 #endif