From 4b17261f97150456ba0a6c56477d5c4e148d4fcc Mon Sep 17 00:00:00 2001
From: Micah Elizabeth Scott <micah@scanlime.org>
Date: Sat, 24 Jan 2015 20:23:05 -0800
Subject: [PATCH] Keep the 'id' attribute for shapes

This remembers the 'id' string for shapes (or their parent groups).

I find this useful for storing pertinent names or metadata in the shape's layer name in Illustrator. When saving the document as SVG, that string ends up in the 'id' attribute.

The library was already saving 'id' attributes for gradients. I didn't see an elegant way to combine that mechanism with this patch, but the small change in attr parsing order should allow the two to coexist.
---
 src/nanosvg.h | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/nanosvg.h b/src/nanosvg.h
index 14a890f..41c5571 100644
--- a/src/nanosvg.h
+++ b/src/nanosvg.h
@@ -126,6 +126,7 @@ typedef struct NSVGpath
 
 typedef struct NSVGshape
 {
+	char id[64];				// Optional 'id' attr of the shape or its group
 	NSVGpaint fill;				// Fill paint
 	NSVGpaint stroke;			// Stroke paint
 	float opacity;				// Opacity of the shape.
@@ -360,6 +361,7 @@ typedef struct NSVGgradientData
 
 typedef struct NSVGattrib
 {
+	char id[64];
 	float xform[6];
 	unsigned int fillColor;
 	unsigned int strokeColor;
@@ -567,6 +569,7 @@ static NSVGparser* nsvg__createParser()
 
 	// Init style
 	nsvg__xformIdentity(p->attr[0].xform);
+	memset(p->attr[0].id, 0, sizeof p->attr[0].id);
 	p->attr[0].fillColor = NSVG_RGB(0,0,0);
 	p->attr[0].strokeColor = NSVG_RGB(0,0,0);
 	p->attr[0].opacity = 1;
@@ -788,6 +791,7 @@ static void nsvg__addShape(NSVGparser* p)
 	if (shape == NULL) goto error;
 	memset(shape, 0, sizeof(NSVGshape));
 
+	memcpy(shape->id, attr->id, sizeof shape->id);
 	scale = nsvg__getAverageScale(attr->xform);
 	shape->strokeWidth = attr->strokeWidth * scale;
 	shape->strokeLineJoin = attr->strokeLineJoin;
@@ -1506,6 +1510,9 @@ static int nsvg__parseAttr(NSVGparser* p, const char* name, const char* value)
 		attr->stopOpacity = nsvg__parseFloat(NULL, value, 2);
 	} else if (strcmp(name, "offset") == 0) {
 		attr->stopOffset = nsvg__parseFloat(NULL, value, 2);
+	} else if (strcmp(name, "id") == 0) {
+		strncpy(attr->id, value, 63);
+		attr->id[63] = '\0';
 	} else {
 		return 0;
 	}
@@ -2276,7 +2283,10 @@ static void nsvg__parseGradient(NSVGparser* p, const char** attr, char type)
 
 	// TODO: does not handle percent and objectBoundingBox correctly yet.
 	for (i = 0; attr[i]; i += 2) {
-		if (!nsvg__parseAttr(p, attr[i], attr[i + 1])) {
+		if (strcmp(attr[i], "id") == 0) {
+			strncpy(grad->id, attr[i+1], 63);
+			grad->id[63] = '\0';
+		} else if (!nsvg__parseAttr(p, attr[i], attr[i + 1])) {
 			if (strcmp(attr[i], "gradientUnits") == 0) {
 				if (strcmp(attr[i+1], "objectBoundingBox") == 0)
 					grad->units = NSVG_OBJECT_SPACE;
@@ -2312,9 +2322,6 @@ static void nsvg__parseGradient(NSVGparser* p, const char** attr, char type)
 			} else if (strcmp(attr[i], "xlink:href") == 0) {
 				strncpy(grad->ref, attr[i+1], 63);
 				grad->ref[63] = '\0';
-			} else if (strcmp(attr[i], "id") == 0) {
-				strncpy(grad->id, attr[i+1], 63);
-				grad->id[63] = '\0';
 			}
 		}
 	}