How to use generated atlas? png+json?

[sergeyvin]

Could you add sample code how to use generated atlas? Do we need to use both PNG file for texture and JSON/CSV file for glyph offsets ?
Sample fragment shader code was given in msdf rep description https://github.com/Chlumsky/msdfgen . Thanks !

[Chlumsky]

Yes, how else would you know where the glyphs are? Here is code that generates vertex data for a given text:

msdf-atlas-gen/msdf-atlas-gen/shadron-preview-generator.cpp

Lines 107 to 143 in dadc65c

	for (const unicode_t *cp = text; *cp; ++cp) {
	if (*cp == '\r')
	continue;
	if (*cp == '\n') {
	textWidth = std::max(textWidth, x);
	x = 0;
	y -= fsScale*fontMetrics.lineHeight;
	continue;
	}
	for (int i = 0; i < fontCount; ++i) {
	const GlyphGeometry *glyph = fonts[i].getGlyph(*cp);
	if (glyph) {
	if (!glyph->isWhitespace()) {
	double pl, pb, pr, pt;
	double il, ib, ir, it;
	glyph->getQuadPlaneBounds(pl, pb, pr, pt);
	glyph->getQuadAtlasBounds(il, ib, ir, it);
	pl *= fsScale, pb *= fsScale, pr *= fsScale, pt *= fsScale;
	pl += x, pb += y, pr += x, pt += y;
	il *= texelWidth, ib *= texelHeight, ir *= texelWidth, it *= texelHeight;
	fprintf(file, " %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g, %.9g,\n",
	pl, pb, il, ib,
	pr, pb, ir, ib,
	pl, pt, il, it,
	pr, pt, ir, it,
	pl, pt, il, it,
	pr, pb, ir, ib
	);
	}
	double advance = glyph->getAdvance();
	fonts[i].getAdvance(advance, cp[0], cp[1]);
	x += fsScale*advance;
	anyGlyphs = true;
	break;
	}
	}
	}

The layout of each vertex is:

msdf-atlas-gen/msdf-atlas-gen/shadron-preview-generator.cpp

Lines 30 to 33 in dadc65c

	glsl struct GlyphVertex {
	vec2 coord;
	vec2 texCoord;
	};