SDL_image: nanosvg: sync with mainstream: (b6330)

From b633019b042d01db04d1d44a208e4c64b501a062 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sun, 4 Dec 2022 18:56:24 +0300
Subject: [PATCH] nanosvg: sync with mainstream:

This imports the following nine commits from mainstream nanosvg:

https://github.com/memononen/nanosvg/commit/f29d7055966d3c06295a8f10ea2ebbdd844d3c2e
https://github.com/memononen/nanosvg/commit/be3670eb13f9120a25ad264efc03e10320ecb550
https://github.com/memononen/nanosvg/commit/a37f87382cd0b56bffe3cf02fdb65a5ce3c75981
https://github.com/memononen/nanosvg/commit/5a7e1449ad1000529996d99598e131cd7fc8ffad
https://github.com/memononen/nanosvg/commit/402437f68aa3feb560d5b2ecb024913d452d3d19
https://github.com/memononen/nanosvg/commit/d2002eeaf20f5b30c41b10a929bf9e368580034b
https://github.com/memononen/nanosvg/commit/34a6c493e78105e3900fa59a8946f4e6c120f4fc
https://github.com/memononen/nanosvg/commit/7bfb035d509664e3d7511da53bc7a6178fc3db16
https://github.com/memononen/nanosvg/commit/0ce2e2bee4f259c014178f7f7b0eb364f1639c97
---
 nanosvg.h     | 152 +++++++++++++++++++++++++++++++++++++++-----------
 nanosvgrast.h |   8 +--
 2 files changed, 124 insertions(+), 36 deletions(-)

diff --git a/nanosvg.h b/nanosvg.h
index 88c2f417..2e554231 100644
--- a/nanosvg.h
+++ b/nanosvg.h
@@ -76,6 +76,7 @@ extern "C" {
 */
 
 enum NSVGpaintType {
+	NSVG_PAINT_UNDEF = -1,
 	NSVG_PAINT_NONE = 0,
 	NSVG_PAINT_COLOR = 1,
 	NSVG_PAINT_LINEAR_GRADIENT = 2,
@@ -123,7 +124,7 @@ typedef struct NSVGgradient {
 } NSVGgradient;
 
 typedef struct NSVGpaint {
-	char type;
+	signed char type;
 	union {
 		unsigned int color;
 		NSVGgradient* gradient;
@@ -147,14 +148,17 @@ typedef struct NSVGshape
 	float opacity;				// Opacity of the shape.
 	float strokeWidth;			// Stroke width (scaled).
 	float strokeDashOffset;		// Stroke dash offset (scaled).
-	float strokeDashArray[8];			// Stroke dash array (scaled).
-	char strokeDashCount;				// Number of dash values in dash array.
+	float strokeDashArray[8];	// Stroke dash array (scaled).
+	char strokeDashCount;		// Number of dash values in dash array.
 	char strokeLineJoin;		// Stroke join type.
 	char strokeLineCap;			// Stroke cap type.
 	float miterLimit;			// Miter limit
 	char fillRule;				// Fill rule, see NSVGfillRule.
 	unsigned char flags;		// Logical or of NSVG_FLAGS_* flags
 	float bounds[4];			// Tight bounding box of the shape [minx,miny,maxx,maxy].
+	char fillGradient[64];		// Optional 'id' of fill gradient
+	char strokeGradient[64];	// Optional 'id' of stroke gradient
+	float xform[6];				// Root transformation for fill/stroke gradient
 	NSVGpath* paths;			// Linked list of paths in the image.
 	struct NSVGshape* next;		// Pointer to next shape, or NULL if last element.
 } NSVGshape;
@@ -403,7 +407,7 @@ typedef struct NSVGgradientData
 {
 	char id[64];
 	char ref[64];
-	char type;
+	signed char type;
 	union {
 		NSVGlinearData linear;
 		NSVGradialData radial;
@@ -845,9 +849,8 @@ static NSVGgradientData* nsvg__findGradientData(NSVGparser* p, const char* id)
 	return NULL;
 }
 
-static NSVGgradient* nsvg__createGradient(NSVGparser* p, const char* id, const float* localBounds, char* paintType)
+static NSVGgradient* nsvg__createGradient(NSVGparser* p, const char* id, const float* localBounds, float *xform, signed char* paintType)
 {
-	NSVGattrib* attr = nsvg__getAttr(p);
 	NSVGgradientData* data = NULL;
 	NSVGgradientData* ref = NULL;
 	NSVGgradientStop* stops = NULL;
@@ -922,7 +925,7 @@ static NSVGgradient* nsvg__createGradient(NSVGparser* p, const char* id, const f
 	}
 
 	nsvg__xformMultiply(grad->xform, data->xform);
-	nsvg__xformMultiply(grad->xform, attr->xform);
+	nsvg__xformMultiply(grad->xform, xform);
 
 	grad->spread = data->spread;
 	memcpy(grad->stops, stops, nstops*sizeof(NSVGgradientStop));
@@ -986,6 +989,9 @@ static void nsvg__addShape(NSVGparser* p)
 	memset(shape, 0, sizeof(NSVGshape));
 
 	memcpy(shape->id, attr->id, sizeof shape->id);
+	memcpy(shape->fillGradient, attr->fillGradient, sizeof shape->fillGradient);
+	memcpy(shape->strokeGradient, attr->strokeGradient, sizeof shape->strokeGradient);
+	memcpy(shape->xform, attr->xform, sizeof shape->xform);
 	scale = nsvg__getAverageScale(attr->xform);
 	shape->strokeWidth = attr->strokeWidth * scale;
 	shape->strokeDashOffset = attr->strokeDashOffset * scale;
@@ -1021,13 +1027,7 @@ static void nsvg__addShape(NSVGparser* p)
 		shape->fill.color = attr->fillColor;
 		shape->fill.color |= (unsigned int)(attr->fillOpacity*255) << 24;
 	} else if (attr->hasFill == 2) {
-		float inv[6], localBounds[4];
-		nsvg__xformInverse(inv, attr->xform);
-		nsvg__getLocalBounds(localBounds, shape, inv);
-		shape->fill.gradient = nsvg__createGradient(p, attr->fillGradient, localBounds, &shape->fill.type);
-		if (shape->fill.gradient == NULL) {
-			shape->fill.type = NSVG_PAINT_NONE;
-		}
+		shape->fill.type = NSVG_PAINT_UNDEF;
 	}
 
 	// Set stroke
@@ -1038,12 +1038,7 @@ static void nsvg__addShape(NSVGparser* p)
 		shape->stroke.color = attr->strokeColor;
 		shape->stroke.color |= (unsigned int)(attr->strokeOpacity*255) << 24;
 	} else if (attr->hasStroke == 2) {
-		float inv[6], localBounds[4];
-		nsvg__xformInverse(inv, attr->xform);
-		nsvg__getLocalBounds(localBounds, shape, inv);
-		shape->stroke.gradient = nsvg__createGradient(p, attr->strokeGradient, localBounds, &shape->stroke.type);
-		if (shape->stroke.gradient == NULL)
-			shape->stroke.type = NSVG_PAINT_NONE;
+		shape->stroke.type = NSVG_PAINT_UNDEF;
 	}
 
 	// Set flags
@@ -1225,6 +1220,19 @@ static const char* nsvg__parseNumber(const char* s, char* it, const int size)
 	return s;
 }
 
+static const char* nsvg__getNextPathItemWhenArcFlag(const char* s, char* it)
+{
+	it[0] = '\0';
+	while (*s && (nsvg__isspace(*s) || *s == ',')) s++;
+	if (!*s) return s;
+	if (*s == '0' || *s == '1') {
+		it[0] = *s++;
+		it[1] = '\0';
+		return s;
+	}
+	return s;
+}
+
 static const char* nsvg__getNextPathItem(const char* s, char* it)
 {
 	it[0] = '\0';
@@ -1253,15 +1261,58 @@ static unsigned int nsvg__parseColorHex(const char* str)
 	return NSVG_RGB(128, 128, 128);
 }
 
+// Parse rgb color. The pointer 'str' must point at "rgb(" (4+ characters).
+// This function returns gray (rgb(128, 128, 128) == '#808080') on parse errors
+// for backwards compatibility. Note: other image viewers return black instead.
+
 static unsigned int nsvg__parseColorRGB(const char* str)
 {
-	unsigned int r=0, g=0, b=0;
-	float rf=0, gf=0, bf=0;
-	if (sscanf(str, "rgb(%u, %u, %u)", &r, &g, &b) == 3)		// decimal integers
-		return NSVG_RGB(r, g, b);
-	if (sscanf(str, "rgb(%f%%, %f%%, %f%%)", &rf, &gf, &bf) == 3)	// decimal integer percentage
-		return NSVG_RGB(roundf(rf*2.55f), roundf(gf*2.55f), roundf(bf*2.55f)); // (255 / 100.0f)
-	return NSVG_RGB(128, 128, 128);
+	int i;
+	unsigned int rgbi[3];
+	float rgbf[3];
+	// try decimal integers first
+	if (sscanf(str, "rgb(%u, %u, %u)", &rgbi[0], &rgbi[1], &rgbi[2]) != 3) {
+		// integers failed, try percent values (float, locale independent)
+		const char delimiter[3] = {',', ',', ')'};
+		str += 4; // skip "rgb("
+		for (i = 0; i < 3; i++) {
+			while (*str && (nsvg__isspace(*str))) str++; 	// skip leading spaces
+			if (*str == '+') str++;				// skip '+' (don't allow '-')
+			if (!*str) break;
+			rgbf[i] = nsvg__atof(str);
+
+			// Note 1: it would be great if nsvg__atof() returned how many
+			// bytes it consumed but it doesn't. We need to skip the number,
+			// the '%' character, spaces, and the delimiter ',' or ')'.
+
+			// Note 2: The following code does not allow values like "33.%",
+			// i.e. a decimal point w/o fractional part, but this is consistent
+			// with other image viewers, e.g. firefox, chrome, eog, gimp.
+
+			while (*str && nsvg__isdigit(*str)) str++;		// skip integer part
+			if (*str == '.') {
+				str++;
+				if (!nsvg__isdigit(*str)) break;		// error: no digit after '.'
+				while (*str && nsvg__isdigit(*str)) str++;	// skip fractional part
+			}
+			if (*str == '%') str++; else break;
+			while (nsvg__isspace(*str)) str++;
+			if (*str == delimiter[i]) str++;
+			else break;
+		}
+		if (i == 3) {
+			rgbi[0] = roundf(rgbf[0] * 2.55f);
+			rgbi[1] = roundf(rgbf[1] * 2.55f);
+			rgbi[2] = roundf(rgbf[2] * 2.55f);
+		} else {
+			rgbi[0] = rgbi[1] = rgbi[2] = 128;
+		}
+	}
+	// clip values as the CSS spec requires
+	for (i = 0; i < 3; i++) {
+		if (rgbi[i] > 255) rgbi[i] = 255;
+	}
+	return NSVG_RGB(rgbi[0], rgbi[1], rgbi[2]);
 }
 
 typedef struct NSVGNamedColor {
@@ -1671,9 +1722,9 @@ static void nsvg__parseUrl(char* id, const char* str)
 {
 	int i = 0;
 	str += 4; // "url(";
-	if (*str == '#')
+	if (*str && *str == '#')
 		str++;
-	while (i < 63 && *str != ')') {
+	while (i < 63 && *str && *str != ')') {
 		id[i] = *str++;
 		i++;
 	}
@@ -2277,7 +2328,11 @@ static void nsvg__parsePath(NSVGparser* p, const char** attr)
 		nargs = 0;
 
 		while (*s) {
-			s = nsvg__getNextPathItem(s, item);
+			item[0] = '\0';
+			if ((cmd == 'A' || cmd == 'a') && (nargs == 3 || nargs == 4))
+				s = nsvg__getNextPathItemWhenArcFlag(s, item);
+			if (!*item)
+				s = nsvg__getNextPathItem(s, item);
 			if (!*item) break;
 			if (cmd != '\0' && nsvg__isCoordinate(item)) {
 				if (nargs < 10)
@@ -2622,7 +2677,7 @@ static void nsvg__parseSVG(NSVGparser* p, const char** attr)
 	}
 }
 
-static void nsvg__parseGradient(NSVGparser* p, const char** attr, char type)
+static void nsvg__parseGradient(NSVGparser* p, const char** attr, signed char type)
 {
 	int i;
 	NSVGgradientData* grad = (NSVGgradientData*)malloc(sizeof(NSVGgradientData));
@@ -3006,6 +3061,36 @@ static void nsvg__scaleToViewbox(NSVGparser* p, const char* units)
 	}
 }
 
+static void nsvg__createGradients(NSVGparser* p)
+{
+	NSVGshape* shape;
+
+	for (shape = p->image->shapes; shape != NULL; shape = shape->next) {
+		if (shape->fill.type == NSVG_PAINT_UNDEF) {
+			if (shape->fillGradient[0] != '\0') {
+				float inv[6], localBounds[4];
+				nsvg__xformInverse(inv, shape->xform);
+				nsvg__getLocalBounds(localBounds, shape, inv);
+				shape->fill.gradient = nsvg__createGradient(p, shape->fillGradient, localBounds, shape->xform, &shape->fill.type);
+			}
+			if (shape->fill.type == NSVG_PAINT_UNDEF) {
+				shape->fill.type = NSVG_PAINT_NONE;
+			}
+		}
+		if (shape->stroke.type == NSVG_PAINT_UNDEF) {
+			if (shape->strokeGradient[0] != '\0') {
+				float inv[6], localBounds[4];
+				nsvg__xformInverse(inv, shape->xform);
+				nsvg__getLocalBounds(localBounds, shape, inv);
+				shape->stroke.gradient = nsvg__createGradient(p, shape->strokeGradient, localBounds, shape->xform, &shape->stroke.type);
+			}
+			if (shape->stroke.type == NSVG_PAINT_UNDEF) {
+				shape->stroke.type = NSVG_PAINT_NONE;
+			}
+		}
+	}
+}
+
 NSVG_EXPORT NSVGimage* nsvgParse(char* input, const char* units, float dpi)
 {
 	NSVGparser* p;
@@ -3019,6 +3104,9 @@ NSVG_EXPORT NSVGimage* nsvgParse(char* input, const char* units, float dpi)
 
 	nsvg__parseXML(input, nsvg__startElement, nsvg__endElement, nsvg__content, p);
 
+	// Create gradients after all definitions have been parsed
+	nsvg__createGradients(p);
+
 	// Scale to viewBox
 	nsvg__scaleToViewbox(p, units);
 
@@ -3109,6 +3197,6 @@ NSVG_EXPORT void nsvgDelete(NSVGimage* image)
 	free(image);
 }
 
-#endif
+#endif // NANOSVG_IMPLEMENTATION
 
 #endif // NANOSVG_H
diff --git a/nanosvgrast.h b/nanosvgrast.h
index ed9cfc6d..4740a5f3 100644
--- a/nanosvgrast.h
+++ b/nanosvgrast.h
@@ -63,8 +63,8 @@ NSVG_EXPORT NSVGrasterizer* nsvgCreateRasterizer(void);
 //   h - height of the image to render
 //   stride - number of bytes per scaleline in the destination buffer
 NSVG_EXPORT void nsvgRasterize(NSVGrasterizer* r,
-				               NSVGimage* image, float tx, float ty, float scale,
-				               unsigned char* dst, int w, int h, int stride);
+		               NSVGimage* image, float tx, float ty, float scale,
+		               unsigned char* dst, int w, int h, int stride);
 
 // Deletes rasterizer context.
 NSVG_EXPORT void nsvgDeleteRasterizer(NSVGrasterizer*);
@@ -116,7 +116,7 @@ typedef struct NSVGmemPage {
 } NSVGmemPage;
 
 typedef struct NSVGcachedPaint {
-	char type;
+	signed char type;
 	char spread;
 	float xform[6];
 	unsigned int colors[256];
@@ -1460,6 +1460,6 @@ NSVG_EXPORT void nsvgRasterize(NSVGrasterizer* r,
 	r->stride = 0;
 }
 
-#endif
+#endif // NANOSVGRAST_IMPLEMENTATION
 
 #endif // NANOSVGRAST_H