8-bit rendering and span scissoring

1 files changed, 139 insertions, 0 deletions

diff --git a/render/rendertext.c b/render/rendertext.c
new file mode 100644
index 00000000..cc181657
--- /dev/null
+++ b/render/rendertext.c
@@ -0,0 +1,139 @@
+#include <fitz.h>
+
+static void blitalphaglyph(fz_pixmap *out, fz_glyph *gl, int xo, int yo)
+{
+	int sx, sy, dx, dy, a, b, c;
+
+	for (sy = 0; sy < gl->h; sy++)
+	{
+		for (sx = 0; sx < gl->w; sx++)
+		{
+			dx = xo + sx + gl->lsb - out->x;
+			dy = yo - sy + gl->top - out->y;
+
+			if (dx < 0) continue;
+			if (dy < 0) continue;
+			if (dx >= out->w) continue;
+			if (dy >= out->h) continue;
+
+			a = gl->bitmap[sx + sy * gl->w];
+			b = out->samples[dx + dy * out->stride];
+			c = MAX(a, b);
+			out->samples[dx + dy * out->stride] = c;
+		}
+	}
+}
+
+static void blitcolorglyph(fz_pixmap *out, fz_glyph *gl, int xo, int yo, fz_renderer *gc)
+{
+	int sx, sy, dx, dy, sa, ssa;
+	unsigned char *p;
+
+	for (sy = 0; sy < gl->h; sy++)
+	{
+		for (sx = 0; sx < gl->w; sx++)
+		{
+			dx = xo + sx + gl->lsb - out->x;
+			dy = yo - sy + gl->top - out->y;
+
+			if (dx < 0) continue;
+			if (dy < 0) continue;
+			if (dx >= out->w) continue;
+			if (dy >= out->h) continue;
+
+			sa = gl->bitmap[sx + sy * gl->w];
+			ssa = 255 - sa;
+
+			p = out->samples + dx * 4 + dy * out->stride;
+			p[0] = fz_mul255(gc->r, sa) + fz_mul255(p[0], ssa);
+			p[1] = fz_mul255(gc->g, sa) + fz_mul255(p[1], ssa);
+			p[2] = fz_mul255(gc->b, sa) + fz_mul255(p[2], ssa);
+			p[3] = sa + fz_mul255(ssa, p[3]);
+		}
+	}
+}
+
+fz_error *
+fz_rendertext(fz_renderer *gc, fz_textnode *text, fz_matrix ctm)
+{
+	fz_error *error;
+	fz_glyph gl;
+	float x, y;
+	int g, i, ix, iy;
+	fz_matrix tm, trm;
+
+	error = fz_newpixmap(&gc->tmp, nil, gc->x, gc->y, gc->w, gc->h, 0, 1);
+	if (error)
+		return error;
+
+	tm = text->trm;
+
+	for (i = 0; i < text->len; i++)
+	{
+		g = text->els[i].cid;
+		x = text->els[i].x;
+		y = text->els[i].y;
+
+		tm.e = x;
+		tm.f = y;
+		trm = fz_concat(tm, ctm);
+
+		ix = floor(trm.e);
+		iy = floor(trm.f);
+
+		trm.e = (trm.e - floor(trm.e));
+		trm.f = (trm.f - floor(trm.f));
+
+		error = fz_renderglyph(gc->cache, &gl, text->font, g, trm);
+		if (error)
+			return error;
+
+		blitalphaglyph(gc->tmp, &gl, ix, iy);
+	}
+
+	return nil;
+}
+
+fz_error *
+fz_rendercolortext(fz_renderer *gc, fz_textnode *text, fz_colornode *color, fz_matrix ctm)
+{
+	fz_error *error;
+	fz_glyph gl;
+	float x, y;
+	int g, i, ix, iy;
+	fz_matrix tm, trm;
+	float rgb[3];
+
+	fz_convertcolor(color->cs, color->samples, gc->model, rgb);
+	gc->r = rgb[0] * 255;
+	gc->g = rgb[1] * 255;
+	gc->b = rgb[2] * 255;
+
+	tm = text->trm;
+
+	for (i = 0; i < text->len; i++)
+	{
+		g = text->els[i].cid;
+		x = text->els[i].x;
+		y = text->els[i].y;
+
+		tm.e = x;
+		tm.f = y;
+		trm = fz_concat(tm, ctm);
+
+		ix = floor(trm.e);
+		iy = floor(trm.f);
+
+		trm.e = (trm.e - floor(trm.e));
+		trm.f = (trm.f - floor(trm.f));
+
+		error = fz_renderglyph(gc->cache, &gl, text->font, g, trm);
+		if (error)
+			return error;
+
+		blitcolorglyph(gc->acc, &gl, ix, iy, gc);
+	}
+
+	return nil;
+}
+