nanovg/src/nanovg.c

//
// Copyright (c) 2013 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty.  In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//

#include <stdio.h>
#include <math.h>
#include "nanovg.h"
#define FONTSTASH_IMPLEMENTATION
#include "fontstash.h"
#define STBI_HEADER_FILE_ONLY
#include "stb_image.c"


#define NVG_INIT_PATH_SIZE 256
#define NVG_MAX_STATES 32

#define NVG_AA 1.0f
#define NVG_KAPPA90 0.5522847493f	// Lenght proportional to radius of a cubic bezier handle for 90deg arcs.

#define NVG_COUNTOF(arr) (sizeof(arr) / sizeof(0[arr]))


enum NVGcommands {
	NVG_MOVETO = 0,
	NVG_LINETO = 1,
	NVG_BEZIERTO = 2,
	NVG_CLOSE = 3,
	NVG_WINDING = 4,
};

enum NVGpointFlags
{
	NVG_BEVEL = 0x01,
	NVG_LEFT = 0x02,
	NVG_CUSP = 0x04,
};

enum NVGexpandFeatures {
	NVG_FILL = 0x01,
	NVG_STROKE = 0x02,
	NVG_CAPS = 0x04,
};

struct NVGstate {
	struct NVGpaint fill;
	struct NVGpaint stroke;
	float strokeWidth;
	float miterLimit;
	float xform[6];
	struct NVGscissor scissor;
	float fontSize;
	float letterSpacing;
	float fontBlur;
	int textAlign;
	int fontId;
};

struct NVGpoint {
	float x,y;
	float dx, dy;
	float len;
	float dmx, dmy;
	unsigned char flags;
};

struct NVGpathCache {
	struct NVGpoint* points;
	int npoints;
	int cpoints;
	struct NVGpath* paths;
	int npaths;
	int cpaths;
	struct NVGvertex* verts;
	int nverts;
	int cverts;
	float bounds[4];
};

struct NVGcontext {
	struct NVGparams params;
	float* commands;
	int ccommands;
	int ncommands;
	float commandx, commandy;
	struct NVGstate states[NVG_MAX_STATES];
	int nstates;
	struct NVGpathCache* cache;
	float tessTol;
	float distTol;
	struct FONScontext* fs;
	int fontImage;
	int drawCallCount;
	int fillTriCount;
	int strokeTriCount;
	int textTriCount;
};

static float nvg__sqrtf(float a) { return sqrtf(a); }
static float nvg__modf(float a, float b) { return fmodf(a, b); }
static float nvg__sinf(float a) { return sinf(a); }
static float nvg__cosf(float a) { return cosf(a); }
static float nvg__tanf(float a) { return tanf(a); }
static float nvg__atan2f(float a,float b) { return atan2f(a, b); }
static float nvg__acosf(float a) { return acosf(a); }

static int nvg__mini(int a, int b) { return a < b ? a : b; }
static int nvg__maxi(int a, int b) { return a > b ? a : b; }
static float nvg__minf(float a, float b) { return a < b ? a : b; }
static float nvg__maxf(float a, float b) { return a > b ? a : b; }
static float nvg__absf(float a) { return a >= 0.0f ? a : -a; }
static float nvg__clampf(float a, float mn, float mx) { return a < mn ? mn : (a > mx ? mx : a); }
static float nvg__cross(float dx0, float dy0, float dx1, float dy1) { return dx1*dy0 - dx0*dy1; }

static float nvg__normalize(float *x, float* y)
{
	float d = nvg__sqrtf((*x)*(*x) + (*y)*(*y));
	if (d > 1e-6f) {
		d = 1.0f / d;
		*x *= d;
		*y *= d;
	}
	return d;
}


static void nvg__deletePathCache(struct NVGpathCache* c)
{
	if (c == NULL) return;
	if (c->points != NULL) free(c->points);
	if (c->paths != NULL) free(c->paths);
	if (c->verts != NULL) free(c->verts);
	free(c);
}

static struct NVGpathCache* nvg__allocPathCache()
{
	struct NVGpathCache* c = (struct NVGpathCache*)malloc(sizeof(struct NVGpathCache));
	if (c == NULL) goto error;
	memset(c, 0, sizeof(struct NVGpathCache));

	c->points = (struct NVGpoint*)malloc(sizeof(struct NVGpoint)*4);
	if (!c->points) goto error;
	c->npoints = 0;
	c->cpoints = 4;

	c->paths = (struct NVGpath*)malloc(sizeof(struct NVGpath)*4);
	if (!c->paths) goto error;
	c->npaths = 0;
	c->cpaths = 4;

	c->verts = (struct NVGvertex*)malloc(sizeof(struct NVGvertex)*4);
	if (!c->verts) goto error;
	c->nverts = 0;
	c->cverts = 4;

	return c;
error:
	nvg__deletePathCache(c);
	return NULL;
}


struct NVGcontext* nvgCreateInternal(struct NVGparams* params)
{
	struct FONSparams fontParams;
	struct NVGcontext* ctx = (struct NVGcontext*)malloc(sizeof(struct NVGcontext));
	if (ctx == NULL) goto error;
	memset(ctx, 0, sizeof(struct NVGcontext));

	ctx->params = *params;

	ctx->commands = (float*)malloc(sizeof(float)*NVG_INIT_PATH_SIZE);
	if (!ctx->commands) goto error;
	ctx->ncommands = 0;
	ctx->ccommands = NVG_INIT_PATH_SIZE;

	ctx->cache = nvg__allocPathCache();
	if (ctx->cache == NULL) goto error;

	nvgSave(ctx);
	nvgReset(ctx);

	ctx->tessTol = 0.3f * 4.0f;
	ctx->distTol = 0.01f;

	if (ctx->params.renderCreate(ctx->params.userPtr) == 0) goto error;

	// Init font rendering
	memset(&fontParams, 0, sizeof(fontParams));
	fontParams.width = params->atlasWidth;
	fontParams.height = params->atlasHeight;
	fontParams.flags = FONS_ZERO_TOPLEFT;
	fontParams.renderCreate = NULL;
	fontParams.renderUpdate = NULL;
	fontParams.renderDraw = NULL;
	fontParams.renderDelete = NULL;
	fontParams.userPtr = NULL;
	ctx->fs = fonsCreateInternal(&fontParams);
	if (ctx->fs == NULL) goto error;

	// Create font texture
	ctx->fontImage = ctx->params.renderCreateTexture(ctx->params.userPtr, NVG_TEXTURE_ALPHA, 512, 512, NULL);
	if (ctx->fontImage == 0) goto error;

	return ctx;

error:
	nvgDeleteInternal(ctx);
	return 0;
}

void nvgDeleteInternal(struct NVGcontext* ctx)
{
	if (ctx == NULL) return;
	if (ctx->commands != NULL) free(ctx->commands);
	if (ctx->cache != NULL) nvg__deletePathCache(ctx->cache);

	if (ctx->fs)
		fonsDeleteInternal(ctx->fs);

	if (ctx->params.renderDelete != NULL)
		ctx->params.renderDelete(ctx->params.userPtr);

	free(ctx);
}

void nvgBeginFrame(struct NVGcontext* ctx)
{
/*	printf("Tris: draws:%d  fill:%d  stroke:%d  text:%d  TOT:%d\n",
		ctx->drawCallCount, ctx->fillTriCount, ctx->strokeTriCount, ctx->textTriCount,
		ctx->fillTriCount+ctx->strokeTriCount+ctx->textTriCount);*/

	ctx->drawCallCount = 0;
	ctx->fillTriCount = 0;
	ctx->strokeTriCount = 0;
	ctx->textTriCount = 0;
}

unsigned int nvgRGB(unsigned char r, unsigned char g, unsigned char b)
{
	return nvgRGBA(r,g,b,255);
}

unsigned int nvgRGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
{
	return (r) | (g << 8) | (b << 16) | (a << 24);
}

unsigned int nvgLerpRGBA(unsigned int c0, unsigned int c1, float u)
{
	int iu = (float)(nvg__clampf(u, 0.0f, 1.0f) * 256.0f);
	int r = (((c0) & 0xff)*(256-iu) + (((c1) & 0xff)*iu)) >> 8;
	int g = (((c0>>8) & 0xff)*(256-iu) + (((c1>>8) & 0xff)*iu)) >> 8;
	int b = (((c0>>16) & 0xff)*(256-iu) + (((c1>>16) & 0xff)*iu)) >> 8;
	int a = (((c0>>24) & 0xff)*(256-iu) + (((c1>>24) & 0xff)*iu)) >> 8;
	return nvgRGBA(r,g,b,a);
}

unsigned int nvgHSL(float h, float s, float l)
{
	return nvgHSLA(h,s,l,255);
}

static float nvg__hue(float h, float m1, float m2)
{
	if (h < 0) h += 1;
	if (h > 1) h -= 1;
	if (h < 1.0f/6.0f)
		return m1 + (m2 - m1) * h * 6.0f;
	else if (h < 3.0f/6.0f)
		return m2;
	else if (h < 4.0f/6.0f)
		return m1 + (m2 - m1) * (2.0f/3.0f - h) * 6.0f;
	return m1;
}

unsigned int nvgHSLA(float h, float s, float l, unsigned char a)
{
	h = nvg__modf(h, 1.0f);
	if (h < 0.0f) h += 1.0f;
	s = nvg__clampf(s, 0.0f, 1.0f);
	l = nvg__clampf(l, 0.0f, 1.0f);
	float m2 = l <= 0.5f ? (l * (1 + s)) : (l + s - l * s);
	float m1 = 2 * l - m2;
	unsigned char r = (unsigned char)nvg__clampf(nvg__hue(h + 1.0f/3.0f, m1, m2) * 255.0f, 0, 255);
	unsigned char g = (unsigned char)nvg__clampf(nvg__hue(h, m1, m2) * 255.0f, 0, 255);
	unsigned char b = (unsigned char)nvg__clampf(nvg__hue(h - 1.0f/3.0f, m1, m2) * 255.0f, 0, 255);
	return nvgRGBA(r,g,b,a);
}


static struct NVGstate* nvg__getState(struct NVGcontext* ctx)
{
	return &ctx->states[ctx->nstates-1];
}

static void nvg__xformIdentity(float* t)
{
	t[0] = 1.0f; t[1] = 0.0f;
	t[2] = 0.0f; t[3] = 1.0f;
	t[4] = 0.0f; t[5] = 0.0f;
}

static void nvg__xformTranslate(float* t, float tx, float ty)
{
	t[0] = 1.0f; t[1] = 0.0f;
	t[2] = 0.0f; t[3] = 1.0f;
	t[4] = tx; t[5] = ty;
}

static void nvg__xformScale(float* t, float sx, float sy)
{
	t[0] = sx; t[1] = 0.0f;
	t[2] = 0.0f; t[3] = sy;
	t[4] = 0.0f; t[5] = 0.0f;
}

static void nvg__xformRotate(float* t, float a)
{
	float cs = nvg__cosf(a), sn = nvg__sinf(a);
	t[0] = cs; t[1] = sn;
	t[2] = -sn; t[3] = cs;
	t[4] = 0.0f; t[5] = 0.0f;
}

static void nvg__xformMultiply(float* t, float* s)
{
	float t0 = t[0] * s[0] + t[1] * s[2];
	float t2 = t[2] * s[0] + t[3] * s[2];
	float t4 = t[4] * s[0] + t[5] * s[2] + s[4];
	t[1] = t[0] * s[1] + t[1] * s[3];
	t[3] = t[2] * s[1] + t[3] * s[3];
	t[5] = t[4] * s[1] + t[5] * s[3] + s[5];
	t[0] = t0;
	t[2] = t2;
	t[4] = t4;
}

static void nvg__xformPremultiply(float* t, float* s)
{
	float s2[6];
	memcpy(s2, s, sizeof(float)*6);
	nvg__xformMultiply(s2, t);
	memcpy(t, s2, sizeof(float)*6);
}

static void nvg__setPaintColor(struct NVGpaint* p, unsigned int color)
{
	memset(p, 0, sizeof(*p));
	nvg__xformIdentity(p->xform);
	p->radius = 0.0f;
	p->feather = 1.0f;
	p->innerColor = color;
	p->outerColor = color;
}


// State handling
void nvgSave(struct NVGcontext* ctx)
{
	if (ctx->nstates >= NVG_MAX_STATES)
		return;
	if (ctx->nstates > 0)
		memcpy(&ctx->states[ctx->nstates], &ctx->states[ctx->nstates-1], sizeof(struct NVGstate));
	ctx->nstates++;
}

void nvgRestore(struct NVGcontext* ctx)
{
	if (ctx->nstates <= 1)
		return;
	ctx->nstates--;
}

void nvgReset(struct NVGcontext* ctx)
{
	struct NVGstate* state = nvg__getState(ctx);
	memset(state, 0, sizeof(*state));

	nvg__setPaintColor(&state->fill, nvgRGBA(255,255,255,255));
	nvg__setPaintColor(&state->stroke, nvgRGBA(0,0,0,255));
	state->strokeWidth = 1.0f;
	state->miterLimit = 1.2f;
	nvg__xformIdentity(state->xform);

	state->scissor.extent[0] = 0.0f;
	state->scissor.extent[1] = 0.0f;

	state->fontSize = 16.0f;
	state->letterSpacing = 0.0f;
	state->fontBlur = 0.0f;
	state->textAlign = NVG_ALIGN_LEFT | NVG_ALIGN_BASELINE;
	state->fontId = 0;
}

// State setting
void nvgStrokeWidth(struct NVGcontext* ctx, float width)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->strokeWidth = width;
}

void nvgMiterLimit(struct NVGcontext* ctx, float limit)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->miterLimit = limit;
}

void nvgTransform(struct NVGcontext* ctx, float a, float b, float c, float d, float e, float f)
{
	struct NVGstate* state = nvg__getState(ctx);
	float t[6] = { a, b, c, d, e, f };
	nvg__xformPremultiply(state->xform, t);
}

void nvgResetTransform(struct NVGcontext* ctx)
{
	struct NVGstate* state = nvg__getState(ctx);
	nvg__xformIdentity(state->xform);
}

void nvgTranslate(struct NVGcontext* ctx, float x, float y)
{
	struct NVGstate* state = nvg__getState(ctx);
	float t[6];
	nvg__xformTranslate(t, x,y);
	nvg__xformPremultiply(state->xform, t);
}

void nvgRotate(struct NVGcontext* ctx, float angle)
{
	struct NVGstate* state = nvg__getState(ctx);
	float t[6];
	nvg__xformRotate(t, angle);
	nvg__xformPremultiply(state->xform, t);
}

void nvgScale(struct NVGcontext* ctx, float x, float y)
{
	struct NVGstate* state = nvg__getState(ctx);
	float t[6];
	nvg__xformScale(t, x,y);
	nvg__xformPremultiply(state->xform, t);
}


void nvgStrokeColor(struct NVGcontext* ctx, unsigned int color)
{
	struct NVGstate* state = nvg__getState(ctx);
	nvg__setPaintColor(&state->stroke, color);
}

void nvgStrokePaint(struct NVGcontext* ctx, struct NVGpaint paint)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->stroke = paint;
	nvg__xformMultiply(state->stroke.xform, state->xform);
}

void nvgFillColor(struct NVGcontext* ctx, unsigned int color)
{
	struct NVGstate* state = nvg__getState(ctx);
	nvg__setPaintColor(&state->fill, color);
}

void nvgFillPaint(struct NVGcontext* ctx, struct NVGpaint paint)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->fill = paint;
	nvg__xformMultiply(state->fill.xform, state->xform);
}

int nvgCreateImage(struct NVGcontext* ctx, const char* filename)
{
	int w, h, n, image;
	unsigned char* img = stbi_load(filename, &w, &h, &n, 4);
	if (img == NULL) {
//		printf("Failed to load %s - %s\n", filename, stbi_failure_reason());
		return 0;
	}
	image = nvgCreateImageRGBA(ctx, w, h, img);
	stbi_image_free(img);
	return image;
}

int nvgCreateImageMem(struct NVGcontext* ctx, unsigned char* data, int ndata, int freeData)
{
	int w, h, n, image;
	unsigned char* img = stbi_load_from_memory(data, ndata, &w, &h, &n, 4);
	if (img == NULL) {
//		printf("Failed to load %s - %s\n", filename, stbi_failure_reason());
		return 0;
	}
	image = nvgCreateImageRGBA(ctx, w, h, img);
	stbi_image_free(img);
	return image;
}

int nvgCreateImageRGBA(struct NVGcontext* ctx, int w, int h, const unsigned char* data)
{
	return ctx->params.renderCreateTexture(ctx->params.userPtr, NVG_TEXTURE_RGBA, w, h, data);
}

void nvgUpdateImage(struct NVGcontext* ctx, int image, const unsigned char* data)
{
	int w, h;
	ctx->params.renderGetTextureSize(ctx->params.userPtr, image, &w, &h);
	ctx->params.renderUpdateTexture(ctx->params.userPtr, image, 0,0, w,h, data);
}

void nvgImageSize(struct NVGcontext* ctx, int image, int* w, int* h)
{
	ctx->params.renderGetTextureSize(ctx->params.userPtr, image, w, h);
}

void nvgDeleteImage(struct NVGcontext* ctx, int image)
{
	ctx->params.renderDeleteTexture(ctx->params.userPtr, image);
}

struct NVGpaint nvgLinearGradient(struct NVGcontext* ctx,
								  float sx, float sy, float ex, float ey,
								  unsigned int icol, unsigned int ocol)
{
	struct NVGpaint p;
	float dx, dy, d;
	const float large = 1e5;

	memset(&p, 0, sizeof(p));

	// Calculate transform aligned to the line
	dx = ex - sx;
	dy = ey - sy;
	d = sqrtf(dx*dx + dy*dy);
	if (d > 0.0001f) {
		dx /= d;
		dy /= d;
	} else {
		dx = 0;
		dy = 1;
	}

	p.xform[0] = dy; p.xform[1] = -dx;
	p.xform[2] = dx; p.xform[3] = dy;
	p.xform[4] = sx - dx*large; p.xform[5] = sy - dy*large;

	p.extent[0] = large;
	p.extent[1] = large + d*0.5f;

	p.radius = 0.0f;

	p.feather = nvg__maxf(1.0f, d);

	p.innerColor = icol;
	p.outerColor = ocol;

	return p;
}

struct NVGpaint nvgRadialGradient(struct NVGcontext* ctx,
								  float cx, float cy, float inr, float outr,
								  unsigned int icol, unsigned int ocol)
{
	struct NVGpaint p;
	float r = (inr+outr)*0.5f;
	float f = (outr-inr);

	memset(&p, 0, sizeof(p));

	nvg__xformIdentity(p.xform);
	p.xform[4] = cx;
	p.xform[5] = cy;

	p.extent[0] = r;
	p.extent[1] = r;

	p.radius = r;

	p.feather = nvg__maxf(1.0f, f);

	p.innerColor = icol;
	p.outerColor = ocol;

	return p;
}

struct NVGpaint nvgBoxGradient(struct NVGcontext* ctx,
							   float x, float y, float w, float h, float r, float f,
							   unsigned int icol, unsigned int ocol)
{
	struct NVGpaint p;

	memset(&p, 0, sizeof(p));

	nvg__xformIdentity(p.xform);
	p.xform[4] = x+w*0.5f;
	p.xform[5] = y+h*0.5f;

	p.extent[0] = w*0.5f;
	p.extent[1] = h*0.5f;

	p.radius = r;

	p.feather = nvg__maxf(1.0f, f);

	p.innerColor = icol;
	p.outerColor = ocol;

	return p;
}


struct NVGpaint nvgImagePattern(struct NVGcontext* ctx,
								float cx, float cy, float w, float h, float angle,
								int image, int repeat)
{
	struct NVGpaint p;

	memset(&p, 0, sizeof(p));

	nvg__xformRotate(p.xform, angle);
	p.xform[4] = cx;
	p.xform[5] = cy;

	p.extent[0] = w;
	p.extent[1] = h;

	p.image = image;
	p.repeat = repeat;

	return p;
}

// Scissoring
void nvgScissor(struct NVGcontext* ctx, float x, float y, float w, float h)
{
	struct NVGstate* state = nvg__getState(ctx);

	nvg__xformIdentity(state->scissor.xform);
	state->scissor.xform[4] = x+w*0.5f;
	state->scissor.xform[5] = y+h*0.5f;
	nvg__xformMultiply(state->scissor.xform, state->xform);

	state->scissor.extent[0] = w*0.5f;
	state->scissor.extent[1] = h*0.5f;
}

void nvgResetScissor(struct NVGcontext* ctx)
{
	struct NVGstate* state = nvg__getState(ctx);
	memset(state->scissor.xform, 0, sizeof(state->scissor.xform));
	state->scissor.extent[0] = 0;
	state->scissor.extent[1] = 0;
}

static void nvg__xformPt(float* dx, float* dy, float sx, float sy, const float* t)
{
	*dx = sx*t[0] + sy*t[2] + t[4];
	*dy = sx*t[1] + sy*t[3] + t[5];
}

static int nvg__ptEquals(float x1, float y1, float x2, float y2, float tol)
{
	float dx = x2 - x1;
	float dy = y2 - y1;
	return dx*dx + dy*dy < tol*tol;
}

static float nvg__distPtSeg(float x, float y, float px, float py, float qx, float qy)
{
	float pqx, pqy, dx, dy, d, t;
	pqx = qx-px;
	pqy = qy-py;
	dx = x-px;
	dy = y-py;
	d = pqx*pqx + pqy*pqy;
	t = pqx*dx + pqy*dy;
	if (d > 0) t /= d;
	if (t < 0) t = 0;
	else if (t > 1) t = 1;
	dx = px + t*pqx - x;
	dy = py + t*pqy - y;
	return dx*dx + dy*dy;
}

static void nvg__appendCommands(struct NVGcontext* ctx, float* vals, int nvals)
{
	struct NVGstate* state = nvg__getState(ctx);
	int i;

	if (ctx->ncommands+nvals > ctx->ccommands) {
		if (ctx->ccommands == 0) ctx->ccommands = 8;
		while (ctx->ccommands < ctx->ncommands+nvals)
			ctx->ccommands *= 2;
		ctx->commands = (float*)realloc(ctx->commands, ctx->ccommands*sizeof(float));
		if (ctx->commands == NULL) return;
	}

	// transform commands
	i = 0;
	while (i < nvals) {
		int cmd = (int)vals[i];
		switch (cmd) {
		case NVG_MOVETO:
			nvg__xformPt(&vals[i+1],&vals[i+2], vals[i+1],vals[i+2], state->xform);
			i += 3;
			break;
		case NVG_LINETO:
			nvg__xformPt(&vals[i+1],&vals[i+2], vals[i+1],vals[i+2], state->xform);
			i += 3;
			break;
		case NVG_BEZIERTO:
			nvg__xformPt(&vals[i+1],&vals[i+2], vals[i+1],vals[i+2], state->xform);
			nvg__xformPt(&vals[i+3],&vals[i+4], vals[i+3],vals[i+4], state->xform);
			nvg__xformPt(&vals[i+5],&vals[i+6], vals[i+5],vals[i+6], state->xform);
			i += 7;
			break;
		case NVG_CLOSE:
			i++;
			break;
		case NVG_WINDING:
			i += 2;
			break;
		default:
			i++;
		}
	}

	memcpy(&ctx->commands[ctx->ncommands], vals, nvals*sizeof(float));

	ctx->ncommands += nvals;

	if ((int)vals[0] != NVG_CLOSE && (int)vals[0] != NVG_WINDING) {
		ctx->commandx = vals[nvals-2];
		ctx->commandy = vals[nvals-1];
	}
}


static void nvg__clearPathCache(struct NVGcontext* ctx)
{
	ctx->cache->npoints = 0;
	ctx->cache->npaths = 0;
}

static struct NVGpath* nvg__lastPath(struct NVGcontext* ctx)
{
	if (ctx->cache->npaths > 0)
		return &ctx->cache->paths[ctx->cache->npaths-1];
	return NULL;
}

static void nvg__addPath(struct NVGcontext* ctx)
{
	struct NVGpath* path;
	if (ctx->cache->npaths+1 > ctx->cache->cpaths) {
		ctx->cache->cpaths = (ctx->cache->cpaths == 0) ? 8 : (ctx->cache->cpaths*2);
		ctx->cache->paths = (struct NVGpath*)realloc(ctx->cache->paths, sizeof(struct NVGpath)*ctx->cache->cpaths);
		if (ctx->cache->paths == NULL) return;
	}
	path = &ctx->cache->paths[ctx->cache->npaths];
	memset(path, 0, sizeof(*path));
	path->first = ctx->cache->npoints;
	path->winding = NVG_CCW;

	ctx->cache->npaths++;
}

static struct NVGpoint* nvg__lastPoint(struct NVGcontext* ctx)
{
	if (ctx->cache->npoints > 0)
		return &ctx->cache->points[ctx->cache->npoints-1];
	return NULL;
}

static void nvg__addPoint(struct NVGcontext* ctx, float x, float y)
{
	struct NVGpath* path = nvg__lastPath(ctx);
	struct NVGpoint* pt;
	if (path == NULL) return;

	if (ctx->cache->npoints > 0) {
		pt = nvg__lastPoint(ctx);
		if (nvg__ptEquals(pt->x,pt->y, x,y, ctx->distTol))
			return;
	}

	if (ctx->cache->npoints+1 > ctx->cache->cpoints) {
		ctx->cache->cpoints = (ctx->cache->cpoints == 0) ? 8 : (ctx->cache->cpoints*2);
		ctx->cache->points = (struct NVGpoint*)realloc(ctx->cache->points, sizeof(struct NVGpoint)*ctx->cache->cpoints);
		if (ctx->cache->points == NULL) return;
	}

	pt = &ctx->cache->points[ctx->cache->npoints];
	memset(pt, 0, sizeof(*pt));
	pt->x = x;
	pt->y = y;

	ctx->cache->npoints++;
	path->count++;
}

static void nvg__closePath(struct NVGcontext* ctx)
{
	struct NVGpath* path = nvg__lastPath(ctx);
	if (path == NULL) return;
	path->closed = 1;
}

static void nvg__pathWinding(struct NVGcontext* ctx, int winding)
{
	struct NVGpath* path = nvg__lastPath(ctx);
	if (path == NULL) return;
	path->winding = winding;
}

static float nvg__getAverageScale(float *t)
{
	float sx = sqrtf(t[0]*t[0] + t[2]*t[2]);
	float sy = sqrtf(t[1]*t[1] + t[3]*t[3]);
	return (sx + sy) * 0.5f;
}

static struct NVGvertex* nvg__allocTempVerts(struct NVGcontext* ctx, int nverts)
{
	if (nverts > ctx->cache->cverts) {
		if (ctx->cache->cverts == 0) ctx->cache->cverts = 8;
		while (ctx->cache->cverts < nverts)
			ctx->cache->cverts *= 2;
		ctx->cache->verts = (struct NVGvertex*)realloc(ctx->cache->verts, sizeof(struct NVGvertex)*ctx->cache->cverts);
		if (ctx->cache->verts == NULL) return NULL;
	}
	return ctx->cache->verts;
}

static float nvg__triarea2(float ax, float ay, float bx, float by, float cx, float cy)
{
	float abx = bx - ax;
	float aby = by - ay;
	float acx = cx - ax;
	float acy = cy - ay;
	return acx*aby - abx*acy;
}

static float nvg__polyArea(struct NVGpoint* pts, int npts)
{
	int i;
	float area = 0;
	for (i = 2; i < npts; i++) {
		struct NVGpoint* a = &pts[0];
		struct NVGpoint* b = &pts[i-1];
		struct NVGpoint* c = &pts[i];
		area += nvg__triarea2(a->x,a->y, b->x,b->y, c->x,c->y);
	}
	return area * 0.5f;
}

static void nvg__polyReverse(struct NVGpoint* pts, int npts)
{
	struct NVGpoint tmp;
	int i = 0, j = npts-1;
	while (i < j) {
		tmp = pts[i];
		pts[i] = pts[j];
		pts[j] = tmp;
		i++;
		j--;
	}
}


static void nvg__vset(struct NVGvertex* vtx, float x, float y, float u, float v)
{
	vtx->x = x;
	vtx->y = y;
	vtx->u = u;
	vtx->v = v;
}

static void nvg__tesselateBezier(struct NVGcontext* ctx,
								 float x1, float y1, float x2, float y2,
								 float x3, float y3, float x4, float y4,
								 int level)
{
	float x12,y12,x23,y23,x34,y34,x123,y123,x234,y234,x1234,y1234;
	
	if (level > 10) return;

	if (nvg__absf(x1+x3-x2-x2) + nvg__absf(y1+y3-y2-y2) + nvg__absf(x2+x4-x3-x3) + nvg__absf(y2+y4-y3-y3) < ctx->tessTol) {
		nvg__addPoint(ctx, x4, y4);
		return;
	}

	x12 = (x1+x2)*0.5f;
	y12 = (y1+y2)*0.5f;
	x23 = (x2+x3)*0.5f;
	y23 = (y2+y3)*0.5f;
	x34 = (x3+x4)*0.5f;
	y34 = (y3+y4)*0.5f;
	x123 = (x12+x23)*0.5f;
	y123 = (y12+y23)*0.5f;
	x234 = (x23+x34)*0.5f;
	y234 = (y23+y34)*0.5f;
	x1234 = (x123+x234)*0.5f;
	y1234 = (y123+y234)*0.5f;

	nvg__tesselateBezier(ctx, x1,y1, x12,y12, x123,y123, x1234,y1234, level+1); 
	nvg__tesselateBezier(ctx, x1234,y1234, x234,y234, x34,y34, x4,y4, level+1); 
}

static void nvg__flattenPaths(struct NVGcontext* ctx, float m)
{
	struct NVGpathCache* cache = ctx->cache;
//	struct NVGstate* state = nvg__getState(ctx);
	struct NVGpoint* last;
	struct NVGpoint* p0;
	struct NVGpoint* p1;
	struct NVGpoint* pts;
	struct NVGpath* path;
	int i, j;
	float* cp1;
	float* cp2;
	float* p;
	float area;

	if (cache->npaths > 0)
		return;

	// Flatten
	i = 0;
	while (i < ctx->ncommands) {
		int cmd = (int)ctx->commands[i];
		switch (cmd) {
		case NVG_MOVETO:
			nvg__addPath(ctx);
			p = &ctx->commands[i+1];
			nvg__addPoint(ctx, p[0], p[1]);
			i += 3;
			break;
		case NVG_LINETO:
			p = &ctx->commands[i+1];
			nvg__addPoint(ctx, p[0], p[1]);
			i += 3;
			break;
		case NVG_BEZIERTO:
			last = nvg__lastPoint(ctx);
			if (last != NULL) {
				cp1 = &ctx->commands[i+1];
				cp2 = &ctx->commands[i+3];
				p = &ctx->commands[i+5];
				nvg__tesselateBezier(ctx, last->x,last->y, cp1[0],cp1[1], cp2[0],cp2[1], p[0],p[1], 0);
			}
			i += 7;
			break;
		case NVG_CLOSE:
			nvg__closePath(ctx);
			i++;
			break;
		case NVG_WINDING:
			nvg__pathWinding(ctx, (int)ctx->commands[i+1]);
			i += 2;
			break;
		default:
			i++;
		}
	}

	cache->bounds[0] = cache->bounds[1] = 1e6f;
	cache->bounds[2] = cache->bounds[3] = -1e6f;

	// Calculate the direction and length of line segments.
	for (j = 0; j < cache->npaths; j++) {
		path = &cache->paths[j];
		pts = &cache->points[path->first];

		// If the first and last points are the same, remove the last, mark as closed path.
		p0 = &pts[path->count-1];
		p1 = &pts[0];
		if (nvg__ptEquals(p0->x,p0->y, p1->x,p1->y, ctx->distTol)) {
			path->count--;
			p0 = &pts[path->count-1];
			path->closed = 1;
		}

		// Enforce winding.
		if (path->count > 2) {
			area = nvg__polyArea(pts, path->count);
			if (path->winding == NVG_CCW && area > 0.0f)
				nvg__polyReverse(pts, path->count);
			if (path->winding == NVG_CW && area < 0.0f)
				nvg__polyReverse(pts, path->count);
		}

		for(i = 0; i < path->count; ++i) {
			// Calculate segment direction and length
			p0->dx = p1->x - p0->x;
			p0->dy = p1->y - p0->y;
			p0->len = nvg__normalize(&p0->dx, &p0->dy);
			// Update bounds
			cache->bounds[0] = nvg__minf(cache->bounds[0], p0->x);
			cache->bounds[1] = nvg__minf(cache->bounds[1], p0->y);
			cache->bounds[2] = nvg__maxf(cache->bounds[2], p0->x);
			cache->bounds[3] = nvg__maxf(cache->bounds[3], p0->y);
			// Advance
			p0 = p1++;
		}
	}

	// Calculate which joins needs extra vertices to append, and gather vertex count.
	for (j = 0; j < cache->npaths; j++) {
		path = &cache->paths[j];
		pts = &cache->points[path->first];
		path->nbevel = 0;

		p0 = &pts[path->count-1];
		p1 = &pts[0];
		for(i = 0; i < path->count; ++i) {
			float dlx0, dly0, dlx1, dly1, dmr2, scale, cross;
			dlx0 = p0->dy;
			dly0 = -p0->dx;
			dlx1 = p1->dy;
			dly1 = -p1->dx;
			// Calculate extrusions			
			p1->dmx = (dlx0 + dlx1) * 0.5f;
			p1->dmy = (dly0 + dly1) * 0.5f;
			dmr2 = p1->dmx*p1->dmx + p1->dmy*p1->dmy;
			if (dmr2 > 0.000001f) {
				scale = 1.0f / dmr2;
				if (scale > 200.0f) scale = 200.0f;
				p1->dmx *= scale;
				p1->dmy *= scale;
			}
			// Check to see if the corner needs to be beveled.
			if ((dmr2 * m*m) < 1.0f) {
				cross = p1->dx * p0->dy - p0->dx * p1->dy;
				p1->flags |= NVG_BEVEL;
				if (cross < 0)
					p1->flags |= NVG_LEFT;
				path->nbevel++;
			}
			p0 = p1++;
		}
	}
}

static int nvg__expandStrokeAndFill(struct NVGcontext* ctx, int feats, float w)
{
	struct NVGpathCache* cache = ctx->cache;
	struct NVGpath* path;
	struct NVGpoint* pts;
	struct NVGvertex* verts;
	struct NVGvertex* dst;
	struct NVGpoint* p0;
	struct NVGpoint* p1;
	int nstroke, cverts;
	int i, j, s, e;
	float wo = 0;

	// Calculate max vertex usage.
	cverts = 0;
	for (i = 0; i < cache->npaths; i++) {
		path = &cache->paths[i];
		if (feats & NVG_FILL)
			cverts += path->count + path->nbevel + 1;
		if (feats & NVG_STROKE) {
			int loop = ((feats & NVG_CAPS) && path->closed == 0) ? 0 : 1;
			cverts += (path->count + path->nbevel + 1) * 2; // plus one for loop
			if (loop == 0)
				cverts += (3+3)*2; // space for caps
		}
	}

	verts = nvg__allocTempVerts(ctx, cverts);
	if (verts == NULL) return 0;

	for (i = 0; i < cache->npaths; i++) {
		path = &cache->paths[i];
		pts = &cache->points[path->first];
		nstroke = (path->count + path->nbevel + 1) * 2;

		// Calculate shape vertices.
		if (feats & NVG_FILL) {
			wo = 0.5f;
			dst = verts;
			path->fill = dst;

			// Looping
			p0 = &pts[path->count-1];
			p1 = &pts[0];
			for (j = 0; j < path->count; ++j) {
				if (p1->flags & NVG_BEVEL) {
					float dlx0 = p0->dy;
					float dly0 = -p0->dx;
					float dlx1 = p1->dy;
					float dly1 = -p1->dx;
					if (p1->flags & NVG_LEFT) {
						float lx = p1->x - p1->dmx * wo;
						float ly = p1->y - p1->dmy * wo;
						nvg__vset(dst, lx, ly, 0.5f,1); dst++;
					} else {
						float lx0 = p1->x - dlx0 * wo;
						float ly0 = p1->y - dly0 * wo;
						float lx1 = p1->x - dlx1 * wo;
						float ly1 = p1->y - dly1 * wo;
						nvg__vset(dst, lx0, ly0, 0.5f,1); dst++;
						nvg__vset(dst, lx1, ly1, 0.5f,1); dst++;
					}
				} else {
					nvg__vset(dst, p1->x - (p1->dmx * wo), p1->y - (p1->dmy * wo), 0.5f,1); dst++;
				}
				p0 = p1++;
			}

			path->nfill = (int)(dst - verts);
			verts += path->nfill;

		} else {
			wo = 0.0f;
			path->fill = 0;
			path->nfill = 0;
		}

		// Calculate fringe
		if (feats & NVG_STROKE) {
			float lw = w + wo; float rw = w - wo;
			int loop = ((feats & NVG_CAPS) && path->closed == 0) ? 0 : 1;
			dst = verts;
			path->stroke = dst;

			if (loop) {
				// Looping
				p0 = &pts[path->count-1];
				p1 = &pts[0];
				s = 0;
				e = path->count;
			} else {
				// Add cap
				p0 = &pts[0];
				p1 = &pts[1];
				s = 1;
				e = path->count-1;
			}

			if (loop == 0) {
				// Add cap
				float dx, dy, dlx, dly;
				dx = p1->x - p0->x;
				dy = p1->y - p0->y;
				nvg__normalize(&dx, &dy);
				dlx = dy;
				dly = -dx;
				nvg__vset(dst, p0->x + dlx*rw - dx*NVG_AA, p0->y + dly*rw - dy*NVG_AA, 0,0); dst++;
				nvg__vset(dst, p0->x - dlx*lw - dx*NVG_AA, p0->y - dly*lw - dy*NVG_AA, 1,0); dst++;
				nvg__vset(dst, p0->x + dlx*rw, p0->y + dly * rw, 0,1); dst++;
				nvg__vset(dst, p0->x - dlx*lw, p0->y - dly * lw, 1,1); dst++;
			}

			for (j = s; j < e; ++j) {
				if (p1->flags & NVG_BEVEL) {
					float dlx0 = p0->dy;
					float dly0 = -p0->dx;
					float dlx1 = p1->dy;
					float dly1 = -p1->dx;
					if (p1->flags & NVG_LEFT) {
						float rx0 = p1->x + dlx0 * rw;
						float ry0 = p1->y + dly0 * rw;
						float rx1 = p1->x + dlx1 * rw;
						float ry1 = p1->y + dly1 * rw;
						float lx = p1->x - p1->dmx * lw;
						float ly = p1->y - p1->dmy * lw;
						nvg__vset(dst, rx0, ry0, 0,1); dst++;
						nvg__vset(dst, lx, ly, 1,1); dst++;
						nvg__vset(dst, rx1, ry1, 0,1); dst++;
						nvg__vset(dst, lx, ly, 1,1); dst++;
					} else {
						float rx = p1->x + p1->dmx * rw;
						float ry = p1->y + p1->dmy * rw;
						float lx0 = p1->x - dlx0 * lw;
						float ly0 = p1->y - dly0 * lw;
						float lx1 = p1->x - dlx1 * lw;
						float ly1 = p1->y - dly1 * lw;
						nvg__vset(dst, rx, ry, 0,1); dst++;
						nvg__vset(dst, lx0, ly0, 1,1); dst++;
						nvg__vset(dst, rx, ry, 0,1); dst++;
						nvg__vset(dst, lx1, ly1, 1,1); dst++;
					}
				} else {
					nvg__vset(dst, p1->x + (p1->dmx * rw), p1->y + (p1->dmy * rw), 0,1); dst++;
					nvg__vset(dst, p1->x - (p1->dmx * lw), p1->y - (p1->dmy * lw), 1,1); dst++;
				}
				p0 = p1++;
			}

			if (loop) {
				// Loop it
				nvg__vset(dst, verts[0].x, verts[0].y, 0,1); dst++;
				nvg__vset(dst, verts[1].x, verts[1].y, 1,1); dst++;
			} else {
				// Add cap
				float dx, dy, dlx, dly;
				dx = p1->x - p0->x;
				dy = p1->y - p0->y;
				nvg__normalize(&dx, &dy);
				dlx = dy;
				dly = -dx;
				nvg__vset(dst, p1->x + dlx*rw, p1->y + dly * rw, 0,1); dst++;
				nvg__vset(dst, p1->x - dlx*lw, p1->y - dly * lw, 1,1); dst++;
				nvg__vset(dst, p1->x + dlx*rw + dx*NVG_AA, p1->y + dly*rw + dy*NVG_AA, 0,0); dst++;
				nvg__vset(dst, p1->x - dlx*lw + dx*NVG_AA, p1->y - dly*lw + dy*NVG_AA, 1,0); dst++;
			}

			path->nstroke = (int)(dst - verts);

			verts += nstroke;
		} else {
			path->stroke = 0;
			path->nstroke = 0;
		}
	}

	return 1;
}


// Draw
void nvgBeginPath(struct NVGcontext* ctx)
{
	ctx->ncommands = 0;
	nvg__clearPathCache(ctx);
}

void nvgMoveTo(struct NVGcontext* ctx, float x, float y)
{
	float vals[] = { NVG_MOVETO, x, y };
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgLineTo(struct NVGcontext* ctx, float x, float y)
{
	float vals[] = { NVG_LINETO, x, y };
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgBezierTo(struct NVGcontext* ctx, float c1x, float c1y, float c2x, float c2y, float x, float y)
{
	float vals[] = { NVG_BEZIERTO, c1x, c1y, c2x, c2y, x, y };
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgArcTo(struct NVGcontext* ctx, float x1, float y1, float x2, float y2, float radius)
{
	float x0 = ctx->commandx;
	float y0 = ctx->commandx;
	float dx0,dy0, dx1,dy1, a, d, cx,cy, a0,a1;
	int dir;

	if (ctx->ncommands == 0) {
		return;
	}

	// Handle degenerate cases.
	if (nvg__ptEquals(x0,y0, x1,y1, ctx->distTol) ||
		nvg__ptEquals(x1,y1, x2,y2, ctx->distTol) ||
		nvg__distPtSeg(x1,y1, x0,y0, x2,y2) < ctx->distTol*ctx->distTol ||
		radius < ctx->distTol) {
		nvgLineTo(ctx, x1,y1);
		return;
	}

	// Calculate tangential circle to lines (x0,y0)-(x1,y1) and (x1,y1)-(x2,y2).
	dx0 = x0-x1;
	dy0 = y0-y1;
	dx1 = x2-x1;
	dy1 = y2-y1;
	nvg__normalize(&dx0,&dy0);
	nvg__normalize(&dx1,&dy1);
	a = nvg__acosf(dx0*dx1 + dy0*dy1);
	d = radius / nvg__tanf(a/2.0f);

	if (d > 10000.0f) {
		nvgLineTo(ctx, x1,y1);
		return;
	}

	if (nvg__cross(dx0,dy0, dx1,dy1) > 0.0f) {
		cx = x1 + dx0*d + dy0*radius;
		cy = y1 + dy0*d + -dx0*radius;
		a0 = nvg__atan2f(dx0, -dy0);
		a1 = nvg__atan2f(-dx1, dy1);
		dir = NVG_CW;
	} else {
		cx = x1 + dx0*d + -dy0*radius;
		cy = y1 + dy0*d + dx0*radius;
		a0 = nvg__atan2f(-dx0, dy0);
		a1 = nvg__atan2f(dx1, -dy1);
		dir = NVG_CCW;
	}

	nvgArc(ctx, cx, cy, radius, a0, a1, dir);
}

void nvgClosePath(struct NVGcontext* ctx)
{
	float vals[] = { NVG_CLOSE };
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgPathWinding(struct NVGcontext* ctx, int dir)
{
	float vals[] = { NVG_WINDING, (float)dir };
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgArc(struct NVGcontext* ctx, float cx, float cy, float r, float a0, float a1, int dir)
{
	float a, da, hda, kappa;
	float dx, dy, x, y, tanx, tany;
	float px, py, ptanx, ptany;
	float vals[3 + 5*7 + 100];
	int i, ndivs, nvals;
	int move = ctx->ncommands > 0 ? NVG_LINETO : NVG_MOVETO; 

	// Clamp angles
	da = a1 - a0;
	if (dir == NVG_CW) {
		if (nvg__absf(da) >= NVG_PI*2) {
			da = NVG_PI*2;
		} else {
			while (da < 0.0f) da += NVG_PI*2;
		}
	} else {
		if (nvg__absf(da) >= NVG_PI*2) {
			da = -NVG_PI*2;
		} else {
			while (da > 0.0f) da -= NVG_PI*2;
		}
	}

	// Split arc into max 90 degree segments.
	ndivs = nvg__maxi(1, nvg__mini((int)(nvg__absf(da) / (NVG_PI*0.5f) + 0.5f), 5));
	hda = (da / (float)ndivs) / 2.0f;
	kappa = nvg__absf(4.0f / 3.0f * (1.0f - nvg__cosf(hda)) / nvg__sinf(hda));

	if (dir == NVG_CCW)
		kappa = -kappa;

	nvals = 0;
	for (i = 0; i <= ndivs; i++) {
		a = a0 + da * (i/(float)ndivs);
		dx = nvg__cosf(a);
		dy = nvg__sinf(a);
		x = cx + dx*r;
		y = cy + dy*r;
		tanx = -dy*r*kappa;
		tany = dx*r*kappa;

		if (i == 0) {
			vals[nvals++] = move;
			vals[nvals++] = x;
			vals[nvals++] = y;
		} else {
			vals[nvals++] = NVG_BEZIERTO;
			vals[nvals++] = px+ptanx;
			vals[nvals++] = py+ptany;
			vals[nvals++] = x-tanx;
			vals[nvals++] = y-tany;
			vals[nvals++] = x;
			vals[nvals++] = y;
		}
		px = x;
		py = y;
		ptanx = tanx;
		ptany = tany;
	}

	nvg__appendCommands(ctx, vals, nvals);
}

void nvgRect(struct NVGcontext* ctx, float x, float y, float w, float h)
{
	float vals[] = {
		NVG_MOVETO, x,y,
		NVG_LINETO, x+w,y,
		NVG_LINETO, x+w,y+h,
		NVG_LINETO, x,y+h,
		NVG_CLOSE
	};
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgRoundedRect(struct NVGcontext* ctx, float x, float y, float w, float h, float r)
{
	if (r < 0.1f) {
		nvgRect(ctx, x,y,w,h);
		return;
	}

	float vals[] = {
		NVG_MOVETO, x+r, y,
		NVG_LINETO, x+w-r, y,
		NVG_BEZIERTO, x+w-r*(1-NVG_KAPPA90), y, x+w, y+r*(1-NVG_KAPPA90), x+w, y+r,
		NVG_LINETO, x+w, y+h-r,
		NVG_BEZIERTO, x+w, y+h-r*(1-NVG_KAPPA90), x+w-r*(1-NVG_KAPPA90), y+h, x+w-r, y+h,
		NVG_LINETO, x+r, y+h,
		NVG_BEZIERTO, x+r*(1-NVG_KAPPA90), y+h, x, y+h-r*(1-NVG_KAPPA90), x, y+h-r,
		NVG_LINETO, x, y+r,
		NVG_BEZIERTO, x, y+r*(1-NVG_KAPPA90), x+r*(1-NVG_KAPPA90), y, x+r, y,
		NVG_CLOSE
	};
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgEllipse(struct NVGcontext* ctx, float cx, float cy, float rx, float ry)
{
	float vals[] = {
		NVG_MOVETO, cx+rx, cy,
		NVG_BEZIERTO, cx+rx, cy+ry*NVG_KAPPA90, cx+rx*NVG_KAPPA90, cy+ry, cx, cy+ry,
		NVG_BEZIERTO, cx-rx*NVG_KAPPA90, cy+ry, cx-rx, cy+ry*NVG_KAPPA90, cx-rx, cy,
		NVG_BEZIERTO, cx-rx, cy-ry*NVG_KAPPA90, cx-rx*NVG_KAPPA90, cy-ry, cx, cy-ry,
		NVG_BEZIERTO, cx+rx*NVG_KAPPA90, cy-ry, cx+rx, cy-ry*NVG_KAPPA90, cx+rx, cy,
		NVG_CLOSE
	};
	nvg__appendCommands(ctx, vals, NVG_COUNTOF(vals));
}

void nvgCircle(struct NVGcontext* ctx, float cx, float cy, float r)
{
	nvgEllipse(ctx, cx,cy, r,r);
}


void nvgFill(struct NVGcontext* ctx)
{
	struct NVGstate* state = nvg__getState(ctx);
	const struct NVGpath* path;
	int i;

	nvg__flattenPaths(ctx, state->miterLimit);
	nvg__expandStrokeAndFill(ctx, NVG_FILL|NVG_STROKE, NVG_AA);

	ctx->params.renderFill(ctx->params.userPtr, &state->fill, &state->scissor, NVG_AA,
						   ctx->cache->bounds, ctx->cache->paths, ctx->cache->npaths);

	// Count triangles
	for (i = 0; i < ctx->cache->npaths; i++) {
		path = &ctx->cache->paths[i];
		ctx->fillTriCount += path->nfill-2;
		ctx->fillTriCount += path->nstroke-2;
		ctx->drawCallCount += 2;
	}
}

void nvgStroke(struct NVGcontext* ctx)
{
	struct NVGstate* state = nvg__getState(ctx);
	float scale = nvg__getAverageScale(state->xform);
	float strokeWidth = nvg__clampf(state->strokeWidth * scale, 1.0f, 20.0f);
	const struct NVGpath* path;
	int i;

	nvg__flattenPaths(ctx, state->miterLimit);
	nvg__expandStrokeAndFill(ctx, NVG_STROKE|NVG_CAPS, strokeWidth*0.5f + NVG_AA/2.0f);

	ctx->params.renderStroke(ctx->params.userPtr, &state->stroke, &state->scissor, NVG_AA,
							 strokeWidth, ctx->cache->paths, ctx->cache->npaths);

	// Count triangles
	for (i = 0; i < ctx->cache->npaths; i++) {
		path = &ctx->cache->paths[i];
		ctx->strokeTriCount += path->nstroke-2;
		ctx->drawCallCount++;
	}
}

// Add fonts
int nvgCreateFont(struct NVGcontext* ctx, const char* name, const char* path)
{
	return fonsAddFont(ctx->fs, name, path);
}

int nvgCreateFontMem(struct NVGcontext* ctx, const char* name, unsigned char* data, int ndata, int freeData)
{
	return fonsAddFontMem(ctx->fs, name, data, ndata, freeData);
}

// State setting
void nvgFontSize(struct NVGcontext* ctx, float size)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->fontSize = size;
}

void nvgLetterSpacing(struct NVGcontext* ctx, float spacing)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->letterSpacing = spacing;
}

void nvgFontBlur(struct NVGcontext* ctx, float blur)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->fontBlur = blur;
}

void nvgTextAlign(struct NVGcontext* ctx, int align)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->textAlign = align;
}

void nvgFontFaceId(struct NVGcontext* ctx, int font)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->fontId = font;
}

void nvgFontFace(struct NVGcontext* ctx, const char* font)
{
	struct NVGstate* state = nvg__getState(ctx);
	state->fontId = fonsGetFontByName(ctx->fs, font);
}

float nvgText(struct NVGcontext* ctx, float x, float y, const char* string, const char* end)
{
	struct NVGstate* state = nvg__getState(ctx);
	struct FONStextIter iter;
	struct FONSquad q;
	struct NVGvertex* verts;
	float scale = nvg__minf(nvg__getAverageScale(state->xform), 4.0f);
	float invscale = 1.0f / scale;
	int dirty[4];
	int cverts = 0;
	int nverts = 0;

	if (end == NULL)
		end = string + strlen(string);

	if (state->fontId == FONS_INVALID) return x;

	fonsSetSize(ctx->fs, state->fontSize*scale);
	fonsSetSpacing(ctx->fs, state->letterSpacing*scale);
	fonsSetBlur(ctx->fs, state->fontBlur*scale);
	fonsSetAlign(ctx->fs, state->textAlign);
	fonsSetFont(ctx->fs, state->fontId);

	cverts = nvg__maxi(2, (int)(end - string)) * 6; // conservative estimate.
	verts = nvg__allocTempVerts(ctx, cverts);
	if (verts == NULL) return x;

	fonsTextIterInit(ctx->fs, &iter, x*scale, y*scale, string, end);
	while (fonsTextIterNext(ctx->fs, &iter, &q)) {
		// Trasnform corners.
		float c[4*2];
		nvg__xformPt(&c[0],&c[1], q.x0*invscale, q.y0*invscale, state->xform);
		nvg__xformPt(&c[2],&c[3], q.x1*invscale, q.y0*invscale, state->xform);
		nvg__xformPt(&c[4],&c[5], q.x1*invscale, q.y1*invscale, state->xform);
		nvg__xformPt(&c[6],&c[7], q.x0*invscale, q.y1*invscale, state->xform);
		// Create triangles
		if (nverts+6 <= cverts) {
			nvg__vset(&verts[nverts], c[0], c[1], q.s0, q.t0); nverts++;
			nvg__vset(&verts[nverts], c[4], c[5], q.s1, q.t1); nverts++;
			nvg__vset(&verts[nverts], c[2], c[3], q.s1, q.t0); nverts++;
			nvg__vset(&verts[nverts], c[0], c[1], q.s0, q.t0); nverts++;
			nvg__vset(&verts[nverts], c[6], c[7], q.s0, q.t1); nverts++;
			nvg__vset(&verts[nverts], c[4], c[5], q.s1, q.t1); nverts++;
		}
	}

	if (fonsValidateTexture(ctx->fs, dirty)) {
		// Update texture
		if (ctx->fontImage != 0) {
			int iw, ih;
			const unsigned char* data = fonsGetTextureData(ctx->fs, &iw, &ih);
			int x = dirty[0];
			int y = dirty[1];
			int w = dirty[2] - dirty[0];
			int h = dirty[3] - dirty[1];
			ctx->params.renderUpdateTexture(ctx->params.userPtr, ctx->fontImage, x,y, w,h, data);
		}
	}

	// Render triangles.
	ctx->params.renderTriangles(ctx->params.userPtr, &state->fill, &state->scissor, ctx->fontImage, verts, nverts);

	ctx->drawCallCount++;
	ctx->textTriCount += nverts/3;

	return iter.x;
}

float nvgTextBounds(struct NVGcontext* ctx, const char* string, const char* end, float* bounds)
{
	struct NVGstate* state = nvg__getState(ctx);
	if (state->fontId == FONS_INVALID) return 0;

	fonsSetSize(ctx->fs, state->fontSize);
	fonsSetSpacing(ctx->fs, state->letterSpacing);
	fonsSetBlur(ctx->fs, state->fontBlur);
	fonsSetAlign(ctx->fs, state->textAlign);
	fonsSetFont(ctx->fs, state->fontId);

	return fonsTextBounds(ctx->fs, string, end, bounds);
}

void nvgVertMetrics(struct NVGcontext* ctx, float* ascender, float* descender, float* lineh)
{
	struct NVGstate* state = nvg__getState(ctx);
	if (state->fontId == FONS_INVALID) return;

	fonsSetSize(ctx->fs, state->fontSize);
	fonsSetSpacing(ctx->fs, state->letterSpacing);
	fonsSetBlur(ctx->fs, state->fontBlur);
	fonsSetAlign(ctx->fs, state->textAlign);
	fonsSetFont(ctx->fs, state->fontId);

	fonsVertMetrics(ctx->fs, ascender, descender, lineh);
}