From f65fb205c4336559da9b1a56e2738622683b639a Mon Sep 17 00:00:00 2001
From: Hanspeter Portner <dev@open-music-kontrollers.ch>
Date: Fri, 10 Aug 2018 18:54:13 +0200
Subject: [PATCH] improve prototype of nanovg backend.

---
 canvas.lv2/render_nanovg.h | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/canvas.lv2/render_nanovg.h b/canvas.lv2/render_nanovg.h
index 030056f..308e306 100644
--- a/canvas.lv2/render_nanovg.h
+++ b/canvas.lv2/render_nanovg.h
@@ -21,10 +21,25 @@
 #include <assert.h>
 
 #include <nanovg.h>
-#define NANOVG_GL3_IMPLEMENTATION
+#include <GL/glew.h>
+#define NANOVG_GL2_IMPLEMENTATION
 #include <GL/gl.h>
 #include <nanovg_gl.h>
 
+#if defined(NANOVG_GL2_IMPLEMENTATION)
+#	define nvgCreate nvgCreateGL2
+#	define nvgDelete nvgDeleteGL2
+#elif defined(NANOVG_GL3_IMPLEMENTATION)
+#	define nvgCreate nvgCreateGL3
+#	define nvgDelete nvgDeleteGL3
+#elif defined(NANOVG_GLES2_IMPLEMENTATION)
+#	define nvgCreate nvgCreateGLES2
+#	define nvgDelete nvgDeleteGLES2
+#elif defined(NANOVG_GLES3_IMPLEMENTATION)
+#	define nvgCreate nvgCreateGLES3
+#	define nvgDelete nvgDeleteGLES3
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -523,15 +538,11 @@ lv2_canvas_render(LV2_Canvas *canvas, NVGcontext *ctx, const LV2_Atom_Tuple *tup
 	nvgSave(ctx);
 
 	// clear surface
-	/* FIXME
-	cairo_set_operator(ctx, CAIRO_OPERATOR_CLEAR);
-	cairo_paint(ctx);
-	*/
-
-	// default attributes
-	/* FIXME
-	cairo_set_operator(ctx, CAIRO_OPERATOR_SOURCE);
-	*/
+	nvgBeginPath(ctx);
+	nvgRect(ctx, 0, 0, 1.f, 1.f);
+	nvgFillColor(ctx, nvgRGBA(0x1e, 0x1e, 0x1e, 0xff));
+	nvgFill(ctx);
+
 	nvgFontSize(ctx, 0.1);
 	nvgStrokeWidth(ctx, 0.01);
 	nvgStrokeColor(ctx, nvgRGBA(0xff, 0xff, 0xff, 0xff));
@@ -559,12 +570,6 @@ lv2_canvas_render(LV2_Canvas *canvas, NVGcontext *ctx, const LV2_Atom_Tuple *tup
 	// save state
 	nvgRestore(ctx);
 
-	// flush
-	/* FIXME
-	cairo_surface_t *surface = cairo_get_target(ctx);
-	cairo_surface_flush(surface);
-	*/
-
 	return true;
 }
 
-- 
2.38.5