From b761d1240c92571351f6c1ec1afaf93111d3efaf Mon Sep 17 00:00:00 2001
From: Olli Wang <olliwang@ollix.com>
Date: Sun, 26 Mar 2017 11:03:52 +0800
Subject: [PATCH] =?UTF-8?q?Allows=20to=20set=20view=20id=20of=20NanoVG?=
 =?UTF-8?q?=E2=80=99s=20framebuffer=20manually.?=
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This commit changes the `nvgluCreateFramebuffer()` function to not assign a view id automatically as it would easily reach the limit of `uint8_t`. Instead, a new `nvgluSetViewFramebuffer()` function is created to allow users to assign the view id manually as mentioned in #1095.
---
 examples/common/nanovg/nanovg_bgfx.cpp | 51 ++++++++++++++++++--------
 examples/common/nanovg/nanovg_bgfx.h   |  3 ++
 2 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/examples/common/nanovg/nanovg_bgfx.cpp b/examples/common/nanovg/nanovg_bgfx.cpp
index ad6f800e7..ffbf28891 100644
--- a/examples/common/nanovg/nanovg_bgfx.cpp
+++ b/examples/common/nanovg/nanovg_bgfx.cpp
@@ -1137,47 +1137,68 @@ bgfx::TextureHandle nvglImageHandle(NVGcontext* ctx, int image)
 	return tex->id;
 }
 
-NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int width,
-																				 int height, int imageFlags) {
+NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int width, int height, int imageFlags, uint8_t viewId)
+{
+  NVGLUframebuffer* framebuffer = nvgluCreateFramebuffer(ctx, width, height, imageFlags);
+	if (framebuffer != nullptr)
+	{
+		nvgluSetViewFramebuffer(viewId, framebuffer);
+	}
+	return framebuffer;
+}
+
+NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int width, int height, int imageFlags)
+{
 	NVGLUframebuffer* framebuffer = new NVGLUframebuffer;
 	framebuffer->ctx = ctx;
 	framebuffer->image = nvgCreateImageRGBA(ctx, width, height, imageFlags | NVG_IMAGE_PREMULTIPLIED, NULL);
 	bgfx::TextureHandle texture = nvglImageHandle(ctx, framebuffer->image);
-	if (!bgfx::isValid(texture)) {
+	if (!bgfx::isValid(texture))
+	{
 		nvgluDeleteFramebuffer(framebuffer);
-		return NULL;
+		return nullptr;
 	}
 	framebuffer->handle = bgfx::createFrameBuffer(1, &texture, false);
 	if (!bgfx::isValid(framebuffer->handle))
 	{
 		nvgluDeleteFramebuffer(framebuffer);
-		return NULL;
+		return nullptr;
 	}
-	static uint8_t s_ViewId = 1;  // may have a better way to assign new view id
-	framebuffer->viewId = s_ViewId++;
-	bgfx::setViewFrameBuffer(framebuffer->viewId, framebuffer->handle);
-	bgfx::setViewSeq(framebuffer->viewId, true);
 	return framebuffer;
 }
 
-void nvgluBindFramebuffer(NVGLUframebuffer* framebuffer) {
-	static NVGcontext* s_prevCtx = NULL;
+void nvgluBindFramebuffer(NVGLUframebuffer* framebuffer)
+{
+	static NVGcontext* s_prevCtx = nullptr;
 	static uint8_t s_prevViewId;
-	if (framebuffer != NULL) {
+	if (framebuffer != nullptr)
+	{
 		s_prevCtx = framebuffer->ctx;
 		s_prevViewId = nvgViewId(framebuffer->ctx);
 		nvgViewId(framebuffer->ctx, framebuffer->viewId);
-	} else if (s_prevCtx != NULL) {
+	} else if (s_prevCtx != nullptr) {
 		nvgViewId(s_prevCtx, s_prevViewId);
 	}
 }
 
-void nvgluDeleteFramebuffer(NVGLUframebuffer* framebuffer) {
-	if (framebuffer == NULL)
+void nvgluDeleteFramebuffer(NVGLUframebuffer* framebuffer)
+{
+	if (framebuffer == nullptr)
 		return;
 	if (bgfx::isValid(framebuffer->handle))
+	{
 		bgfx::destroyFrameBuffer(framebuffer->handle);
+	}
 	if (framebuffer->image > 0)
+	{
 		nvgDeleteImage(framebuffer->ctx, framebuffer->image);
+	}
 	delete framebuffer;
 }
+
+void nvgluSetViewFramebuffer(uint8_t viewId, NVGLUframebuffer* framebuffer)
+{
+	framebuffer->viewId = viewId;
+	bgfx::setViewFrameBuffer(viewId, framebuffer->handle);
+	bgfx::setViewSeq(viewId, true);
+}
diff --git a/examples/common/nanovg/nanovg_bgfx.h b/examples/common/nanovg/nanovg_bgfx.h
index 100a3c22b..36ba0dd73 100644
--- a/examples/common/nanovg/nanovg_bgfx.h
+++ b/examples/common/nanovg/nanovg_bgfx.h
@@ -30,6 +30,7 @@ void nvgViewId(struct NVGcontext* ctx, unsigned char _viewId);
 // Example:
 //		float scale = 2;
 //		NVGLUframebuffer* fb = nvgluCreateFramebuffer(ctx, 100 * scale, 100 * scale, 0);
+//		nvgluSetViewFramebuffer(VIEW_ID, fb);
 //		nvgluBindFramebuffer(fb);
 //		nvgBeginFrame(ctx, 100, 100, scale);
 //		// renders anything offscreen
@@ -44,8 +45,10 @@ void nvgViewId(struct NVGcontext* ctx, unsigned char _viewId);
 //		nvgFillPaint(ctx, paint);
 //		nvgFill(ctx);
 //		nvgEndFrame(ctx);
+NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int width, int height, int imageFlags, uint8_t viewId);
 NVGLUframebuffer* nvgluCreateFramebuffer(NVGcontext* ctx, int width, int height, int imageFlags);
 void nvgluBindFramebuffer(NVGLUframebuffer* framebuffer);
 void nvgluDeleteFramebuffer(NVGLUframebuffer* framebuffer);
+void nvgluSetViewFramebuffer(uint8_t viewId, NVGLUframebuffer* framebuffer);
 
 #endif // NANOVG_BGFX_H_HEADER_GUARD