nanovg/example/demo.c

#include "demo.h"
#include <stdio.h>
#include <string.h>
#include <math.h>
#ifdef NANOVG_GLEW
#  include <GL/glew.h>
#endif
#include <GLFW/glfw3.h>
#include "nanovg.h"
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"


#ifdef _MSC_VER
#define snprintf _snprintf
#else
#include <iconv.h>
#endif

#define ICON_SEARCH 0x1F50D
#define ICON_CIRCLED_CROSS 0x2716
#define ICON_CHEVRON_RIGHT 0xE75E
#define ICON_CHECK 0x2713
#define ICON_LOGIN 0xE740
#define ICON_TRASH 0xE729

static char* cpToUTF8(int cp, char* str)
{
	int n = 0;
	if (cp < 0x80) n = 1;
	else if (cp < 0x800) n = 2;
	else if (cp < 0x10000) n = 3;
	else if (cp < 0x200000) n = 4;
	else if (cp < 0x4000000) n = 5;
	else if (cp <= 0x7fffffff) n = 6;
	str[n] = '\0';
	switch (n) {
	case 6: str[5] = 0x80 | (cp & 0x3f); cp = cp >> 6; cp |= 0x4000000;
	case 5: str[4] = 0x80 | (cp & 0x3f); cp = cp >> 6; cp |= 0x200000;
	case 4: str[3] = 0x80 | (cp & 0x3f); cp = cp >> 6; cp |= 0x10000;
	case 3: str[2] = 0x80 | (cp & 0x3f); cp = cp >> 6; cp |= 0x800;
	case 2: str[1] = 0x80 | (cp & 0x3f); cp = cp >> 6; cp |= 0xc0;
	case 1: str[0] = cp;
	}
	return str;
}


void drawWindow(struct NVGcontext* vg, const char* title, float x, float y, float w, float h)
{
	float cornerRadius = 3.0f;
	struct NVGpaint shadowPaint;
	struct NVGpaint headerPaint;

	nvgSave(vg);
//	nvgClearState(vg);

	// Window
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x,y, w,h, cornerRadius);
	nvgFillColor(vg, nvgRGBA(28,30,34,192));
//	nvgFillColor(vg, nvgRGBA(0,0,0,128));
	nvgFill(vg);

	// Drop shadow
	shadowPaint = nvgBoxGradient(vg, x,y+2, w,h, cornerRadius*2, 10, nvgRGBA(0,0,0,128), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, x-10,y-10, w+20,h+30);
	nvgRoundedRect(vg, x,y, w,h, cornerRadius);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, shadowPaint);
	nvgFill(vg);

	// Header
	headerPaint = nvgLinearGradient(vg, x,y,x,y+15, nvgRGBA(255,255,255,8), nvgRGBA(0,0,0,16));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+1,y+1, w-2,30, cornerRadius-1);
	nvgFillPaint(vg, headerPaint);
	nvgFill(vg);
	nvgBeginPath(vg);
	nvgMoveTo(vg, x+0.5f, y+0.5f+30);
	nvgLineTo(vg, x+0.5f+w-1, y+0.5f+30);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,32));
	nvgStroke(vg);

	nvgFontSize(vg, 18.0f);
	nvgFontFace(vg, "sans-bold");
	nvgTextAlign(vg,NVG_ALIGN_CENTER|NVG_ALIGN_MIDDLE);

	nvgFontBlur(vg,2);
	nvgFillColor(vg, nvgRGBA(0,0,0,128));
	nvgText(vg, x+w/2,y+16+1, title, NULL);

	nvgFontBlur(vg,0);
	nvgFillColor(vg, nvgRGBA(220,220,220,160));
	nvgText(vg, x+w/2,y+16, title, NULL);

	nvgRestore(vg);
}

void drawSearchBox(struct NVGcontext* vg, const char* text, float x, float y, float w, float h)
{
	struct NVGpaint bg;
	char icon[8];
	float cornerRadius = h/2-1;

	// Edit
	bg = nvgBoxGradient(vg, x,y+1.5f, w,h, h/2,5, nvgRGBA(0,0,0,16), nvgRGBA(0,0,0,92));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x,y, w,h, cornerRadius);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

/*	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+0.5f,y+0.5f, w-1,h-1, cornerRadius-0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,48));
	nvgStroke(vg);*/

	nvgFontSize(vg, h*1.3f);
	nvgFontFace(vg, "icons");
	nvgFillColor(vg, nvgRGBA(255,255,255,64));
	nvgTextAlign(vg,NVG_ALIGN_CENTER|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+h*0.55f, y+h*0.55f, cpToUTF8(ICON_SEARCH,icon), NULL);

	nvgFontSize(vg, 20.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,32));

	nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+h*1.05f,y+h*0.5f,text, NULL);

	nvgFontSize(vg, h*1.3f);
	nvgFontFace(vg, "icons");
	nvgFillColor(vg, nvgRGBA(255,255,255,32));
	nvgTextAlign(vg,NVG_ALIGN_CENTER|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+w-h*0.55f, y+h*0.55f, cpToUTF8(ICON_CIRCLED_CROSS,icon), NULL);
}

void drawDropDown(struct NVGcontext* vg, const char* text, float x, float y, float w, float h)
{
	struct NVGpaint bg;
	char icon[8];
	float cornerRadius = 4.0f;

	bg = nvgLinearGradient(vg, x,y,x,y+h, nvgRGBA(255,255,255,16), nvgRGBA(0,0,0,16));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+1,y+1, w-2,h-2, cornerRadius-1);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+0.5f,y+0.5f, w-1,h-1, cornerRadius-0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,48));
	nvgStroke(vg);

	nvgFontSize(vg, 20.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,160));
	nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+h*0.3f,y+h*0.5f,text, NULL);

	nvgFontSize(vg, h*1.3f);
	nvgFontFace(vg, "icons");
	nvgFillColor(vg, nvgRGBA(255,255,255,64));
	nvgTextAlign(vg,NVG_ALIGN_CENTER|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+w-h*0.5f, y+h*0.5f, cpToUTF8(ICON_CHEVRON_RIGHT,icon), NULL);
}

void drawLabel(struct NVGcontext* vg, const char* text, float x, float y, float w, float h)
{
	NVG_NOTUSED(w);

	nvgFontSize(vg, 18.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,128));

	nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x,y+h*0.5f,text, NULL);
}

void drawEditBoxBase(struct NVGcontext* vg, float x, float y, float w, float h)
{
	struct NVGpaint bg;
	// Edit
	bg = nvgBoxGradient(vg, x+1,y+1+1.5f, w-2,h-2, 3,4, nvgRGBA(255,255,255,32), nvgRGBA(32,32,32,32));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+1,y+1, w-2,h-2, 4-1);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+0.5f,y+0.5f, w-1,h-1, 4-0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,48));
	nvgStroke(vg);
}

void drawEditBox(struct NVGcontext* vg, const char* text, float x, float y, float w, float h)
{

	drawEditBoxBase(vg, x,y, w,h);

	nvgFontSize(vg, 20.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,64));
	nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+h*0.3f,y+h*0.5f,text, NULL);
}

void drawEditBoxNum(struct NVGcontext* vg,
					const char* text, const char* units, float x, float y, float w, float h)
{
	float uw;

	drawEditBoxBase(vg, x,y, w,h);

	uw = nvgTextBounds(vg, units, NULL, NULL);

	nvgFontSize(vg, 18.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,64));
	nvgTextAlign(vg,NVG_ALIGN_RIGHT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+w-h*0.3f,y+h*0.5f,units, NULL);

	nvgFontSize(vg, 20.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,128));
	nvgTextAlign(vg,NVG_ALIGN_RIGHT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+w-uw-h*0.5f,y+h*0.5f,text, NULL);
}

void drawCheckBox(struct NVGcontext* vg, const char* text, float x, float y, float w, float h)
{
	struct NVGpaint bg;
	char icon[8];
	NVG_NOTUSED(w);

	nvgFontSize(vg, 18.0f);
	nvgFontFace(vg, "sans");
	nvgFillColor(vg, nvgRGBA(255,255,255,160));

	nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+28,y+h*0.5f,text, NULL);

	bg = nvgBoxGradient(vg, x+1,y+(int)(h*0.5f)-9+1, 18,18, 3,3, nvgRGBA(0,0,0,32), nvgRGBA(0,0,0,92));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+1,y+(int)(h*0.5f)-9, 18,18, 3);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	nvgFontSize(vg, 40);
	nvgFontFace(vg, "icons");
	nvgFillColor(vg, nvgRGBA(255,255,255,128));
	nvgTextAlign(vg,NVG_ALIGN_CENTER|NVG_ALIGN_MIDDLE);
	nvgText(vg, x+9+2, y+h*0.5f, cpToUTF8(ICON_CHECK,icon), NULL);
}

void drawButton(struct NVGcontext* vg, int preicon, const char* text, float x, float y, float w, float h, unsigned int col)
{
	struct NVGpaint bg;
	char icon[8];
	float cornerRadius = 4.0f;
	float tw = 0, iw = 0;

	bg = nvgLinearGradient(vg, x,y,x,y+h, nvgRGBA(255,255,255,col==0?16:32), nvgRGBA(0,0,0,col==0?16:32));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+1,y+1, w-2,h-2, cornerRadius-1);
	if (col != 0) {
		nvgFillColor(vg, col);
		nvgFill(vg);
	}
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+0.5f,y+0.5f, w-1,h-1, cornerRadius-0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,48));
	nvgStroke(vg);

	nvgFontSize(vg, 20.0f);
	nvgFontFace(vg, "sans-bold");
	tw = nvgTextBounds(vg, text, NULL, NULL);
	if (preicon != 0) {
		nvgFontSize(vg, h*1.3f);
		nvgFontFace(vg, "icons");
		iw = nvgTextBounds(vg, cpToUTF8(preicon,icon), NULL, NULL);
		iw += h*0.15f;
	}

	if (preicon != 0) {
		nvgFontSize(vg, h*1.3f);
		nvgFontFace(vg, "icons");
		nvgFillColor(vg, nvgRGBA(255,255,255,96));
		nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
		nvgText(vg, x+w*0.5f-tw*0.5f-iw*0.75f, y+h*0.5f, cpToUTF8(preicon,icon), NULL);
	}

	nvgFontSize(vg, 20.0f);
	nvgFontFace(vg, "sans-bold");
	nvgTextAlign(vg,NVG_ALIGN_LEFT|NVG_ALIGN_MIDDLE);
	nvgFillColor(vg, nvgRGBA(0,0,0,160));
	nvgText(vg, x+w*0.5f-tw*0.5f+iw*0.25f,y+h*0.5f-1,text, NULL);
	nvgFillColor(vg, nvgRGBA(255,255,255,160));
	nvgText(vg, x+w*0.5f-tw*0.5f+iw*0.25f,y+h*0.5f,text, NULL);
}

void drawSlider(struct NVGcontext* vg, float pos, float x, float y, float w, float h)
{
	struct NVGpaint bg, knob;
	float cy = y+(int)(h*0.5f);
	float kr = (int)(h*0.25f);

	nvgSave(vg);
//	nvgClearState(vg);

	// Slot
	bg = nvgBoxGradient(vg, x,cy-2+1, w,4, 2,2, nvgRGBA(0,0,0,32), nvgRGBA(0,0,0,128));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x,cy-2, w,4, 2);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	// Knob Shadow
	bg = nvgRadialGradient(vg, x+(int)(pos*w),cy+1, kr-3,kr+3, nvgRGBA(0,0,0,64), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, x+(int)(pos*w)-kr-5,cy-kr-5,kr*2+5+5,kr*2+5+5+3);
	nvgCircle(vg, x+(int)(pos*w),cy, kr);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	// Knob
	knob = nvgLinearGradient(vg, x,cy-kr,x,cy+kr, nvgRGBA(255,255,255,16), nvgRGBA(0,0,0,16));
	nvgBeginPath(vg);
	nvgCircle(vg, x+(int)(pos*w),cy, kr-1);
	nvgFillColor(vg, nvgRGBA(40,43,48,255));
	nvgFill(vg);
	nvgFillPaint(vg, knob);
	nvgFill(vg);

	nvgBeginPath(vg);
	nvgCircle(vg, x+(int)(pos*w),cy, kr-0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,92));
	nvgStroke(vg);

	nvgRestore(vg);
}

void drawEyes(struct NVGcontext* vg, float x, float y, float w, float h, float mx, float my, float t)
{
	struct NVGpaint gloss, bg;
	float ex = w *0.23f;
	float ey = h * 0.5f;
	float lx = x + ex;
	float ly = y + ey;
	float rx = x + w - ex;
	float ry = y + ey;
	float dx,dy,d;
	float br = (ex < ey ? ex : ey) * 0.5f;
	float blink = 1 - pow(sinf(t*0.5f),200)*0.8f;

	bg = nvgLinearGradient(vg, x,y+h*0.5f,x+w*0.1f,y+h, nvgRGBA(0,0,0,32), nvgRGBA(0,0,0,16));
	nvgBeginPath(vg);
	nvgEllipse(vg, lx+3.0f,ly+16.0f, ex,ey);
	nvgEllipse(vg, rx+3.0f,ry+16.0f, ex,ey);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	bg = nvgLinearGradient(vg, x,y+h*0.25f,x+w*0.1f,y+h, nvgRGBA(220,220,220,255), nvgRGBA(128,128,128,255));
	nvgBeginPath(vg);
	nvgEllipse(vg, lx,ly, ex,ey);
	nvgEllipse(vg, rx,ry, ex,ey);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	dx = (mx - rx) / (ex * 10);
	dy = (my - ry) / (ey * 10);
	d = sqrtf(dx*dx+dy*dy);
	if (d > 1.0f) {
		dx /= d; dy /= d;
	}
	dx *= ex*0.4f;
	dy *= ey*0.5f;
	nvgBeginPath(vg);
	nvgEllipse(vg, lx+dx,ly+dy+ey*0.25f*(1-blink), br,br*blink);
	nvgFillColor(vg, nvgRGBA(32,32,32,255));
	nvgFill(vg);

	dx = (mx - rx) / (ex * 10);
	dy = (my - ry) / (ey * 10);
	d = sqrtf(dx*dx+dy*dy);
	if (d > 1.0f) {
		dx /= d; dy /= d;
	}
	dx *= ex*0.4f;
	dy *= ey*0.5f;
	nvgBeginPath(vg);
	nvgEllipse(vg, rx+dx,ry+dy+ey*0.25f*(1-blink), br,br*blink);
	nvgFillColor(vg, nvgRGBA(32,32,32,255));
	nvgFill(vg);

	gloss = nvgRadialGradient(vg, lx-ex*0.25f,ly-ey*0.5f, ex*0.1f,ex*0.75f, nvgRGBA(255,255,255,128), nvgRGBA(255,255,255,0));
	nvgBeginPath(vg);
	nvgEllipse(vg, lx,ly, ex,ey);
	nvgFillPaint(vg, gloss);
	nvgFill(vg);

	gloss = nvgRadialGradient(vg, rx-ex*0.25f,ry-ey*0.5f, ex*0.1f,ex*0.75f, nvgRGBA(255,255,255,128), nvgRGBA(255,255,255,0));
	nvgBeginPath(vg);
	nvgEllipse(vg, rx,ry, ex,ey);
	nvgFillPaint(vg, gloss);
	nvgFill(vg);
}

void drawGraph(struct NVGcontext* vg, float x, float y, float w, float h, float t)
{
	struct NVGpaint bg;
	float samples[6];
	float sx[6], sy[6];
	float dx = w/5.0f;
	int i;

	samples[0] = (1+sinf(t*1.2345f+cosf(t*0.33457f)*0.44f))*0.5f;
	samples[1] = (1+sinf(t*0.68363f+cosf(t*1.3f)*1.55f))*0.5f;
	samples[2] = (1+sinf(t*1.1642f+cosf(t*0.33457)*1.24f))*0.5f;
	samples[3] = (1+sinf(t*0.56345f+cosf(t*1.63f)*0.14f))*0.5f;
	samples[4] = (1+sinf(t*1.6245f+cosf(t*0.254f)*0.3f))*0.5f;
	samples[5] = (1+sinf(t*0.345f+cosf(t*0.03f)*0.6f))*0.5f;

	for (i = 0; i < 6; i++) {
		sx[i] = x+i*dx;
		sy[i] = y+h*samples[i]*0.8f;
	}

	// Graph background
	bg = nvgLinearGradient(vg, x,y,x,y+h, nvgRGBA(0,160,192,0), nvgRGBA(0,160,192,64));
	nvgBeginPath(vg);
	nvgMoveTo(vg, sx[0], sy[0]);
	for (i = 1; i < 6; i++)
		nvgBezierTo(vg, sx[i-1]+dx*0.5f,sy[i-1], sx[i]-dx*0.5f,sy[i], sx[i],sy[i]);
	nvgLineTo(vg, x+w, y+h);
	nvgLineTo(vg, x, y+h);
	nvgFillPaint(vg, bg);
	nvgFill(vg);

	// Graph line
	nvgBeginPath(vg);
	nvgMoveTo(vg, sx[0], sy[0]+2);
	for (i = 1; i < 6; i++)
		nvgBezierTo(vg, sx[i-1]+dx*0.5f,sy[i-1]+2, sx[i]-dx*0.5f,sy[i]+2, sx[i],sy[i]+2);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,32));
	nvgStrokeWidth(vg, 3.0f);
	nvgStroke(vg);

	nvgBeginPath(vg);
	nvgMoveTo(vg, sx[0], sy[0]);
	for (i = 1; i < 6; i++)
		nvgBezierTo(vg, sx[i-1]+dx*0.5f,sy[i-1], sx[i]-dx*0.5f,sy[i], sx[i],sy[i]);
	nvgStrokeColor(vg, nvgRGBA(0,160,192,255));
	nvgStrokeWidth(vg, 3.0f);
	nvgStroke(vg);

	// Graph sample pos
	for (i = 0; i < 6; i++) {
		bg = nvgRadialGradient(vg, sx[i],sy[i]+2, 3.0f,8.0f, nvgRGBA(0,0,0,32), nvgRGBA(0,0,0,0));
		nvgBeginPath(vg);
		nvgRect(vg, sx[i]-10, sy[i]-10+2, 20,20);
		nvgFillPaint(vg, bg);
		nvgFill(vg);
	}

	nvgBeginPath(vg);
	for (i = 0; i < 6; i++)
		nvgCircle(vg, sx[i], sy[i], 4.0f);
	nvgFillColor(vg, nvgRGBA(0,160,192,255));
	nvgFill(vg);
	nvgBeginPath(vg);
	for (i = 0; i < 6; i++)
		nvgCircle(vg, sx[i], sy[i], 2.0f);
	nvgFillColor(vg, nvgRGBA(220,220,220,255));
	nvgFill(vg);

	nvgStrokeWidth(vg, 1.0f);
}

void drawThumbnails(struct NVGcontext* vg, float x, float y, float w, float h, const int* images, int nimages, float t)
{
	float cornerRadius = 3.0f;
	struct NVGpaint shadowPaint, imgPaint, fadePaint;
	float ix,iy,iw,ih;
	float thumb = 60.0f;
	float arry = 30.5f;
	int imgw, imgh;
	float stackh = (nimages/2) * (thumb+10) + 10;
	int i;
	float u = (1+cosf(t*0.5f))*0.5f;
	float scrollh;

	nvgSave(vg);
//	nvgClearState(vg);

	// Drop shadow
	shadowPaint = nvgBoxGradient(vg, x,y+4, w,h, cornerRadius*2, 20, nvgRGBA(0,0,0,128), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, x-10,y-10, w+20,h+30);
	nvgRoundedRect(vg, x,y, w,h, cornerRadius);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, shadowPaint);
	nvgFill(vg);

	// Window
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x,y, w,h, cornerRadius);
	nvgMoveTo(vg, x-10,y+arry);
	nvgLineTo(vg, x+1,y+arry-11);
	nvgLineTo(vg, x+1,y+arry+11);
	nvgFillColor(vg, nvgRGBA(200,200,200,255));
	nvgFill(vg);

	nvgSave(vg);
	nvgScissor(vg, x,y,w,h);
	nvgTranslate(vg, 0, -(stackh - h)*u);

	for (i = 0; i < nimages; i++) {
		float tx, ty;
		tx = x+10;
		ty = y+10;
		tx += (i%2) * (thumb+10);
		ty += (i/2) * (thumb+10);
		nvgImageSize(vg, images[i], &imgw, &imgh);
		if (imgw < imgh) {
			iw = thumb;
			ih = iw * (float)imgh/(float)imgw;
			ix = 0;
			iy = -(ih-thumb)*0.5f;
		} else {
			ih = thumb;
			iw = ih * (float)imgw/(float)imgh;
			ix = -(iw-thumb)*0.5f;
			iy = 0;
		}
		imgPaint = nvgImagePattern(vg, tx+ix, ty+iy, iw,ih, 0.0f/180.0f*NVG_PI, images[i], 0);
		nvgBeginPath(vg);
		nvgRoundedRect(vg, tx,ty, thumb,thumb, 5);
		nvgFillPaint(vg, imgPaint);
		nvgFill(vg);

		shadowPaint = nvgBoxGradient(vg, tx-1,ty, thumb+2,thumb+2, 5, 3, nvgRGBA(0,0,0,128), nvgRGBA(0,0,0,0));
		nvgBeginPath(vg);
		nvgRect(vg, tx-5,ty-5, thumb+10,thumb+10);
		nvgRoundedRect(vg, tx,ty, thumb,thumb, 6);
		nvgPathWinding(vg, NVG_HOLE);
		nvgFillPaint(vg, shadowPaint);
		nvgFill(vg);

		nvgBeginPath(vg);
		nvgRoundedRect(vg, tx+0.5f,ty+0.5f, thumb-1,thumb-1, 4-0.5f);
		nvgStrokeWidth(vg,1.0f);
		nvgStrokeColor(vg, nvgRGBA(255,255,255,192));
		nvgStroke(vg);
	}
	nvgRestore(vg);

	// Hide fades
	fadePaint = nvgLinearGradient(vg, x,y,x,y+6, nvgRGBA(200,200,200,255), nvgRGBA(200,200,200,0));
	nvgBeginPath(vg);
	nvgRect(vg, x+4,y,w-8,6);
	nvgFillPaint(vg, fadePaint);
	nvgFill(vg);

	fadePaint = nvgLinearGradient(vg, x,y+h,x,y+h-6, nvgRGBA(200,200,200,255), nvgRGBA(200,200,200,0));
	nvgBeginPath(vg);
	nvgRect(vg, x+4,y+h-6,w-8,6);
	nvgFillPaint(vg, fadePaint);
	nvgFill(vg);

	// Scroll bar
	shadowPaint = nvgBoxGradient(vg, x+w-12+1,y+4+1, 8,h-8, 3,4, nvgRGBA(0,0,0,32), nvgRGBA(0,0,0,92));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+w-12,y+4, 8,h-8, 3);
	nvgFillPaint(vg, shadowPaint);
//	nvgFillColor(vg, nvgRGBA(255,0,0,128));
	nvgFill(vg);

	scrollh = (h/stackh) * (h-8);
	shadowPaint = nvgBoxGradient(vg, x+w-12-1,y+4+(h-8-scrollh)*u-1, 8,scrollh, 3,4, nvgRGBA(220,220,220,255), nvgRGBA(128,128,128,255));
	nvgBeginPath(vg);
	nvgRoundedRect(vg, x+w-12+1,y+4+1 + (h-8-scrollh)*u, 8-2,scrollh-2, 2);
	nvgFillPaint(vg, shadowPaint);
//	nvgFillColor(vg, nvgRGBA(0,0,0,128));
	nvgFill(vg);

	nvgRestore(vg);
}

void drawColorwheel(struct NVGcontext* vg, float x, float y, float w, float h, float t)
{
	int i;
	float r0, r1, ax,ay, bx,by, cx,cy, aeps, r;
	float hue = sinf(t * 0.12f);
	struct NVGpaint paint;

	nvgSave(vg);

/*	nvgBeginPath(vg);
	nvgRect(vg, x,y,w,h);
	nvgFillColor(vg, nvgRGBA(255,0,0,128));
	nvgFill(vg);*/

	cx = x + w*0.5f;
	cy = y + h*0.5f;
	r1 = (w < h ? w : h) * 0.5f - 5.0f;
	r0 = r1 - 20.0f;
	aeps = 0.5f / r1;	// half a pixel arc length in radians (2pi cancels out).

	for (i = 0; i < 6; i++) {
		float a0 = (float)i / 6.0f * NVG_PI * 2.0f - aeps;
		float a1 = (float)(i+1.0f) / 6.0f * NVG_PI * 2.0f + aeps;
		nvgBeginPath(vg);
		nvgArc(vg, cx,cy, r0, a0, a1, NVG_CW);
		nvgArc(vg, cx,cy, r1, a1, a0, NVG_CCW);
		nvgClosePath(vg);
		ax = cx + cosf(a0) * (r0+r1)*0.5f;
		ay = cy + sinf(a0) * (r0+r1)*0.5f;
		bx = cx + cosf(a1) * (r0+r1)*0.5f;
		by = cy + sinf(a1) * (r0+r1)*0.5f;
		paint = nvgLinearGradient(vg, ax,ay, bx,by, nvgHSLA(a0/(NVG_PI*2),1.0f,0.55f,255), nvgHSLA(a1/(NVG_PI*2),1.0f,0.55f,255));
		nvgFillPaint(vg, paint);
		nvgFill(vg);
	}

	nvgBeginPath(vg);
	nvgCircle(vg, cx,cy, r0-0.5f);
	nvgCircle(vg, cx,cy, r1+0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,64));
	nvgStrokeWidth(vg, 1.0f);
	nvgStroke(vg);

	// Selector
	nvgSave(vg);
	nvgTranslate(vg, cx,cy);
	nvgRotate(vg, hue*NVG_PI*2);

	// Marker on
	nvgStrokeWidth(vg, 2.0f);
	nvgBeginPath(vg);
	nvgRect(vg, r0-1,-3,r1-r0+2,6);
	nvgStrokeColor(vg, nvgRGBA(255,255,255,192));
	nvgStroke(vg);

	paint = nvgBoxGradient(vg, r0-3,-5,r1-r0+6,10, 2,4, nvgRGBA(0,0,0,128), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, r0-2-10,-4-10,r1-r0+4+20,8+20);
	nvgRect(vg, r0-2,-4,r1-r0+4,8);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, paint);
	nvgFill(vg);

	// Center triangle
	r = r0 - 6;
	ax = cosf(120.0f/180.0f*NVG_PI) * r;
	ay = sinf(120.0f/180.0f*NVG_PI) * r;
	bx = cosf(-120.0f/180.0f*NVG_PI) * r;
	by = sinf(-120.0f/180.0f*NVG_PI) * r;
	nvgBeginPath(vg);
	nvgMoveTo(vg, r,0);
	nvgLineTo(vg, ax,ay);
	nvgLineTo(vg, bx,by);
	nvgClosePath(vg);
	paint = nvgLinearGradient(vg, r,0, ax,ay, nvgHSLA(hue,1.0f,0.5f,255), nvgRGBA(255,255,255,255));
	nvgFillPaint(vg, paint);
	nvgFill(vg);
	paint = nvgLinearGradient(vg, (r+ax)*0.5f,(0+ay)*0.5f, bx,by, nvgRGBA(0,0,0,0), nvgRGBA(0,0,0,255));
	nvgFillPaint(vg, paint);
	nvgFill(vg);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,64));
	nvgStroke(vg);

	// Select circle on triangle
	ax = cosf(120.0f/180.0f*NVG_PI) * r*0.3f;
	ay = sinf(120.0f/180.0f*NVG_PI) * r*0.4f;
	nvgStrokeWidth(vg, 2.0f);
	nvgBeginPath(vg);
	nvgCircle(vg, ax,ay,5);
	nvgStrokeColor(vg, nvgRGBA(255,255,255,192));
	nvgStroke(vg);

	paint = nvgRadialGradient(vg, ax,ay, 7,9, nvgRGBA(0,0,0,64), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, ax-20,ay-20,40,40);
	nvgCircle(vg, ax,ay,7);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, paint);
	nvgFill(vg);

	nvgRestore(vg);

	nvgRestore(vg);
}

void drawLines(struct NVGcontext* vg, float x, float y, float w, float h, float t)
{
	int i, j;
	float pad = 5.0f, s = w/9.0f - pad*2;
	float pts[4*2], fx, fy;
	int joins[3] = {NVG_MITER, NVG_ROUND, NVG_BEVEL};
	int caps[3] = {NVG_BUTT, NVG_ROUND, NVG_SQUARE};
	NVG_NOTUSED(h);

	nvgSave(vg);
	pts[0] = -s*0.25f + cosf(t*0.3f) * s*0.5f;
	pts[1] = sinf(t*0.3f) * s*0.5f;
	pts[2] = -s*0.25;
	pts[3] = 0;
	pts[4] = s*0.25f;
	pts[5] = 0;
	pts[6] = s*0.25f + cosf(-t*0.3f) * s*0.5f;
	pts[7] = sinf(-t*0.3f) * s*0.5f;

	for (i = 0; i < 3; i++) {
		for (j = 0; j < 3; j++) {
			fx = x + s*0.5f + (i*3+j)/9.0f*w + pad;
			fy = y - s*0.5f + pad;

			nvgLineCap(vg, caps[i]);
			nvgLineJoin(vg, joins[j]);

			nvgStrokeWidth(vg, s*0.3f);
			nvgStrokeColor(vg, nvgRGBA(0,0,0,160));
			nvgBeginPath(vg);
			nvgMoveTo(vg, fx+pts[0], fy+pts[1]);
			nvgLineTo(vg, fx+pts[2], fy+pts[3]);
			nvgLineTo(vg, fx+pts[4], fy+pts[5]);
			nvgLineTo(vg, fx+pts[6], fy+pts[7]);
			nvgStroke(vg);

			nvgLineCap(vg, NVG_BUTT);
			nvgLineJoin(vg, NVG_BEVEL);

			nvgStrokeWidth(vg, 1.0f);
			nvgStrokeColor(vg, nvgRGBA(0,192,255,255));
			nvgBeginPath(vg);
			nvgMoveTo(vg, fx+pts[0], fy+pts[1]);
			nvgLineTo(vg, fx+pts[2], fy+pts[3]);
			nvgLineTo(vg, fx+pts[4], fy+pts[5]);
			nvgLineTo(vg, fx+pts[6], fy+pts[7]);
			nvgStroke(vg);
		}
	}


	nvgRestore(vg);
}

int loadDemoData(struct NVGcontext* vg, struct DemoData* data)
{
	int i;

	if (vg == NULL)
		return -1;

	for (i = 0; i < 12; i++) {
		char file[128];
		snprintf(file, 128, "../example/images/image%d.jpg", i+1);
		data->images[i] = nvgCreateImage(vg, file);
		if (data->images[i] == 0) {
			printf("Could not load %s.\n", file);
			return -1;
		}
	}

	data->fontIcons = nvgCreateFont(vg, "icons", "../example/entypo.ttf");
	if (data->fontIcons == -1) {
		printf("Could not add font icons.\n");
		return -1;
	}
	data->fontNormal = nvgCreateFont(vg, "sans", "../example/Roboto-Regular.ttf");
	if (data->fontNormal == -1) {
		printf("Could not add font italic.\n");
		return -1;
	}
	data->fontBold = nvgCreateFont(vg, "sans-bold", "../example/Roboto-Bold.ttf");
	if (data->fontBold == -1) {
		printf("Could not add font bold.\n");
		return -1;
	}

	return 0;
}

void freeDemoData(struct NVGcontext* vg, struct DemoData* data)
{
	int i;

	if (vg == NULL)
		return;

	for (i = 0; i < 12; i++)
		nvgDeleteImage(vg, data->images[i]);
}

void renderDemo(struct NVGcontext* vg, float mx, float my, float width, float height,
				float t, int blowup, struct DemoData* data)
{
	float x,y,popy;

	drawEyes(vg, width - 250, 50, 150, 100, mx, my, t);
	drawGraph(vg, 0, height/2, width, height/2, t);
	drawColorwheel(vg, width - 300, height - 300, 250.0f, 250.0f, t);

	// Line joints
	drawLines(vg, 50, height-50, 600, 50, t);

	nvgSave(vg);
	if (blowup) {
		nvgRotate(vg, sinf(t*0.3f)*5.0f/180.0f*NVG_PI);
		nvgScale(vg, 2.0f, 2.0f);
	}

	// Widgets
	drawWindow(vg, "Widgets `n Stuff", 50, 50, 300, 400);
	x = 60; y = 95;
	drawSearchBox(vg, "Search", x,y,280,25);
	y += 40;
	drawDropDown(vg, "Effects", x,y,280,28);
	popy = y + 14;
	y += 45;

	// Form
	drawLabel(vg, "Login", x,y, 280,20);
	y += 25;
	drawEditBox(vg, "Email",  x,y, 280,28);
	y += 35;
	drawEditBox(vg, "Password", x,y, 280,28);
	y += 38;
	drawCheckBox(vg, "Remember me", x,y, 140,28);
	drawButton(vg, ICON_LOGIN, "Sign in", x+138, y, 140, 28, nvgRGBA(0,96,128,255));
	y += 45;

	// Slider
	drawLabel(vg, "Diameter", x,y, 280,20);
	y += 25;
	drawEditBoxNum(vg, "123.00", "px", x+180,y, 100,28);
	drawSlider(vg, 0.4f, x,y, 170,28);
	y += 55;

	drawButton(vg, ICON_TRASH, "Delete", x, y, 160, 28, nvgRGBA(128,16,8,255));
	drawButton(vg, 0, "Cancel", x+170, y, 110, 28, nvgRGBA(0,0,0,0));

	// Thumbnails box
	drawThumbnails(vg, 365, popy-30, 160, 300, data->images, 12, t);

	nvgRestore(vg);
}

static int mini(int a, int b) { return a < b ? a : b; }

static void unpremultiplyAlpha(unsigned char* image, int w, int h, int stride)
{
	int x,y;

	// Unpremultiply
	for (y = 0; y < h; y++) {
		unsigned char *row = &image[y*stride];
		for (x = 0; x < w; x++) {
			int r = row[0], g = row[1], b = row[2], a = row[3];
			if (a != 0) {
				row[0] = (int)mini(r*255/a, 255);
				row[1] = (int)mini(g*255/a, 255);
				row[2] = (int)mini(b*255/a, 255);
			}
			row += 4;
		}
	}

	// Defringe
	for (y = 0; y < h; y++) {
		unsigned char *row = &image[y*stride];
		for (x = 0; x < w; x++) {
			int r = 0, g = 0, b = 0, a = row[3], n = 0;
			if (a == 0) {
				if (x-1 > 0 && row[-1] != 0) {
					r += row[-4];
					g += row[-3];
					b += row[-2];
					n++;
				}
				if (x+1 < w && row[7] != 0) {
					r += row[4];
					g += row[5];
					b += row[6];
					n++;
				}
				if (y-1 > 0 && row[-stride+3] != 0) {
					r += row[-stride];
					g += row[-stride+1];
					b += row[-stride+2];
					n++;
				}
				if (y+1 < h && row[stride+3] != 0) {
					r += row[stride];
					g += row[stride+1];
					b += row[stride+2];
					n++;
				}
				if (n > 0) {
					row[0] = r/n;
					row[1] = g/n;
					row[2] = b/n;
				}
			}
			row += 4;
		}
	}
}

static void setAlpha(unsigned char* image, int w, int h, int stride, unsigned char a)
{
	int x, y;
	for (y = 0; y < h; y++) {
		unsigned char* row = &image[y*stride];
		for (x = 0; x < w; x++)
			row[x*4+3] = a;
	}
}

static void flipHorizontal(unsigned char* image, int w, int h, int stride)
{
	int i = 0, j = h-1, k;
	while (i < j) {
		unsigned char* ri = &image[i * stride];		
		unsigned char* rj = &image[j * stride];		
		for (k = 0; k < w*4; k++) {
			unsigned char t = ri[k];
			ri[k] = rj[k];
			rj[k] = t;
		}
		i++;
		j--;
	}
}

void saveScreenShot(int w, int h, int premult, const char* name)
{
	unsigned char* image = (unsigned char*)malloc(w*h*4);
	if (image == NULL)
		return;
	glReadPixels(0, 0, w, h, GL_RGBA, GL_UNSIGNED_BYTE, image);
	if (premult)
		unpremultiplyAlpha(image, w, h, w*4);
	else
		setAlpha(image, w, h, w*4, 255);
	flipHorizontal(image, w, h, w*4);
 	stbi_write_png(name, w, h, 4, image, w*4);
 	free(image);
}