Rename fitzdraw directory to draw.

1 files changed, 398 insertions, 0 deletions

diff --git a/draw/meshdraw.c b/draw/meshdraw.c
new file mode 100644
index 00000000..d756db12
--- /dev/null
+++ b/draw/meshdraw.c
@@ -0,0 +1,398 @@
+#include "fitz.h"
+
+/*
+ * polygon clipping
+ */
+
+enum { IN, OUT, ENTER, LEAVE };
+enum { MAXV = 3 + 4 };
+enum { MAXN = 2 + FZ_MAXCOLORS };
+
+static int clipx(float val, int ismax, float *v1, float *v2, int n)
+{
+	float t;
+	int i;
+	int v1o = ismax ? v1[0] > val : v1[0] < val;
+	int v2o = ismax ? v2[0] > val : v2[0] < val;
+	if (v1o + v2o == 0)
+		return IN;
+	if (v1o + v2o == 2)
+		return OUT;
+	if (v2o)
+	{
+		t = (val - v1[0]) / (v2[0] - v1[0]);
+		v2[0] = val;
+		v2[1] = v1[1] + t * (v2[1] - v1[1]);
+		for (i = 2; i < n; i++)
+			v2[i] = v1[i] + t * (v2[i] - v1[i]);
+		return LEAVE;
+	}
+	else
+	{
+		t = (val - v2[0]) / (v1[0] - v2[0]);
+		v1[0] = val;
+		v1[1] = v2[1] + t * (v1[1] - v2[1]);
+		for (i = 2; i < n; i++)
+			v1[i] = v2[i] + t * (v1[i] - v2[i]);
+		return ENTER;
+	}
+}
+
+static int clipy(float val, int ismax, float *v1, float *v2, int n)
+{
+	float t;
+	int i;
+	int v1o = ismax ? v1[1] > val : v1[1] < val;
+	int v2o = ismax ? v2[1] > val : v2[1] < val;
+	if (v1o + v2o == 0)
+		return IN;
+	if (v1o + v2o == 2)
+		return OUT;
+	if (v2o)
+	{
+		t = (val - v1[1]) / (v2[1] - v1[1]);
+		v2[0] = v1[0] + t * (v2[0] - v1[0]);
+		v2[1] = val;
+		for (i = 2; i < n; i++)
+			v2[i] = v1[i] + t * (v2[i] - v1[i]);
+		return LEAVE;
+	}
+	else
+	{
+		t = (val - v2[1]) / (v1[1] - v2[1]);
+		v1[0] = v2[0] + t * (v1[0] - v2[0]);
+		v1[1] = val;
+		for (i = 2; i < n; i++)
+			v1[i] = v2[i] + t * (v1[i] - v2[i]);
+		return ENTER;
+	}
+}
+
+static inline void copyvert(float *dst, float *src, int n)
+{
+	while (n--)
+		*dst++ = *src++;
+}
+
+static int clippoly(float src[MAXV][MAXN],
+	float dst[MAXV][MAXN], int len, int n,
+	float val, int isy, int ismax)
+{
+	float cv1[MAXN];
+	float cv2[MAXN];
+	int v1, v2, cp;
+	int r;
+
+	v1 = len - 1;
+	cp = 0;
+
+	for (v2 = 0; v2 < len; v2++)
+	{
+		copyvert(cv1, src[v1], n);
+		copyvert(cv2, src[v2], n);
+
+		if (isy)
+			r = clipy(val, ismax, cv1, cv2, n);
+		else
+			r = clipx(val, ismax, cv1, cv2, n);
+
+		switch (r)
+		{
+		case IN:
+			copyvert(dst[cp++], cv2, n);
+			break;
+		case OUT:
+			break;
+		case LEAVE:
+			copyvert(dst[cp++], cv2, n);
+			break;
+		case ENTER:
+			copyvert(dst[cp++], cv1, n);
+			copyvert(dst[cp++], cv2, n);
+			break;
+		}
+		v1 = v2;
+	}
+
+	return cp;
+}
+
+/*
+ * gouraud shaded polygon scan conversion
+ */
+
+static inline void
+drawscan(fz_pixmap *pix, int y, int x1, int x2, int *v1, int *v2, int n)
+{
+	unsigned char *p = pix->samples + ((y - pix->y) * pix->w + (x1 - pix->x)) * pix->n;
+	int v[FZ_MAXCOLORS];
+	int dv[FZ_MAXCOLORS];
+	int w = x2 - x1;
+	int k;
+
+	assert(w >= 0);
+	assert(y >= pix->y);
+	assert(y < pix->y + pix->h);
+	assert(x1 >= pix->x);
+	assert(x2 <= pix->x + pix->w);
+
+	if (w == 0)
+		return;
+
+	for (k = 0; k < n; k++)
+	{
+		v[k] = v1[k];
+		dv[k] = (v2[k] - v1[k]) / w;
+	}
+
+	while (w--)
+	{
+		*p++ = 255;
+		for (k = 0; k < n; k++)
+		{
+			*p++ = v[k] >> 16;
+			v[k] += dv[k];
+		}
+	}
+}
+
+static inline int
+findnext(int gel[MAXV][MAXN], int len, int a, int *s, int *e, int d)
+{
+	int b;
+
+	while (1)
+	{
+		b = a + d;
+		if (b == len)
+			b = 0;
+		if (b == -1)
+			b = len - 1;
+
+		if (gel[b][1] == gel[a][1])
+		{
+			a = b;
+			continue;
+		}
+
+		if (gel[b][1] > gel[a][1])
+		{
+			*s = a;
+			*e = b;
+			return 0;
+		}
+
+		return 1;
+	}
+}
+
+static inline void
+loadedge(int gel[MAXV][MAXN], int s, int e, int *ael, int *del, int n)
+{
+	int swp, k, dy;
+
+	if (gel[s][1] > gel[s][1])
+	{
+		swp = s; s = e; e = swp;
+	}
+
+	dy = gel[e][1] - gel[s][1];
+
+	ael[0] = gel[s][0];
+	del[0] = (gel[e][0] - gel[s][0]) / dy;
+	for (k = 2; k < n; k++)
+	{
+		ael[k] = gel[s][k];
+		del[k] = (gel[e][k] - gel[s][k]) / dy;
+	}
+}
+
+static inline void
+stepedge(int *ael, int *del, int n)
+{
+	int k;
+	ael[0] += del[0];
+	for (k = 2; k < n; k++)
+		ael[k] += del[k];
+}
+
+static void
+fz_drawtriangle(fz_pixmap *pix, float *av, float *bv, float *cv, int n)
+{
+	float poly[MAXV][MAXN];
+	float temp[MAXV][MAXN];
+	float cx0 = pix->x;
+	float cy0 = pix->y;
+	float cx1 = pix->x + pix->w;
+	float cy1 = pix->y + pix->h;
+
+	int gel[MAXV][MAXN];
+	int ael[2][MAXN];
+	int del[2][MAXN];
+	int y, s0, s1, e0, e1;
+	int top, bot, len;
+
+	int i, k;
+
+	copyvert(poly[0], av, n);
+	copyvert(poly[1], bv, n);
+	copyvert(poly[2], cv, n);
+
+	len = clippoly(poly, temp,   3, n, cx0, 0, 0);
+	len = clippoly(temp, poly, len, n, cx1, 0, 1);
+	len = clippoly(poly, temp, len, n, cy0, 1, 0);
+	len = clippoly(temp, poly, len, n, cy1, 1, 1);
+
+	if (len < 3)
+		return;
+
+	for (i = 0; i < len; i++)
+	{
+		gel[i][0] = fz_floor(poly[i][0] + 0.5) * 65536; /* trunc and fix */
+		gel[i][1] = fz_floor(poly[i][1] + 0.5);	/* y is not fixpoint */
+		for (k = 2; k < n; k++)
+			gel[i][k] = poly[i][k] * 65536;	/* fix with precision */
+	}
+
+	top = bot = 0;
+	for (i = 0; i < len; i++)
+	{
+		if (gel[i][1] < gel[top][1])
+			top = i;
+		if (gel[i][1] > gel[bot][1])
+			bot = i;
+	}
+
+	if (gel[bot][1] - gel[top][1] == 0)
+		return;
+
+	y = gel[top][1];
+
+	if (findnext(gel, len, top, &s0, &e0,  1))
+		return;
+	if (findnext(gel, len, top, &s1, &e1, -1))
+		return;
+
+	loadedge(gel, s0, e0, ael[0], del[0], n);
+	loadedge(gel, s1, e1, ael[1], del[1], n);
+
+	while (1)
+	{
+		int x0 = ael[0][0] >> 16;
+		int x1 = ael[1][0] >> 16;
+
+		if (ael[0][0] < ael[1][0])
+			drawscan(pix, y, x0, x1, ael[0]+2, ael[1]+2, n-2);
+		else
+			drawscan(pix, y, x1, x0, ael[1]+2, ael[0]+2, n-2);
+
+		stepedge(ael[0], del[0], n);
+		stepedge(ael[1], del[1], n);
+		y ++;
+
+		if (y >= gel[e0][1])
+		{
+			if (findnext(gel, len, e0, &s0, &e0, 1))
+				return;
+			loadedge(gel, s0, e0, ael[0], del[0], n);
+		}
+
+		if (y >= gel[e1][1])
+		{
+			if (findnext(gel, len, e1, &s1, &e1, -1))
+				return;
+			loadedge(gel, s1, e1, ael[1], del[1], n);
+		}
+	}
+}
+
+/*
+ * mesh drawing
+ */
+
+void
+fz_rendershade(fz_shade *shade, fz_matrix ctm, fz_colorspace *destcs, fz_pixmap *dest)
+{
+	unsigned char clut[256][3];
+	unsigned char *s, *d;
+	fz_pixmap *temp;
+	float rgb[3];
+	float tri[3][MAXN];
+	fz_point p;
+	int i, j, k, n;
+
+	assert(dest->n == 4);
+
+	ctm = fz_concat(shade->matrix, ctm);
+
+	if (shade->usefunction)
+	{
+		n = 3;
+		temp = fz_newpixmap(pdf_devicegray, dest->x, dest->y, dest->w, dest->h);
+	}
+	else if (shade->cs != destcs)
+	{
+		n = 2 + shade->cs->n;
+		temp = fz_newpixmap(shade->cs, dest->x, dest->y, dest->w, dest->h);
+	}
+	else
+	{
+		n = 2 + shade->cs->n;
+		temp = dest;
+	}
+
+	fz_clearpixmap(temp, 0);
+
+	for (i = 0; i < shade->meshlen; i++)
+	{
+		for (k = 0; k < 3; k++)
+		{
+			p.x = shade->mesh[(i * 3 + k) * n + 0];
+			p.y = shade->mesh[(i * 3 + k) * n + 1];
+			p = fz_transformpoint(ctm, p);
+			if (isnan(p.y) || isnan(p.x)) // How is this happening?
+				goto baddata;
+			tri[k][0] = p.x;
+			tri[k][1] = p.y;
+			for (j = 2; j < n; j++)
+				tri[k][j] = shade->mesh[( i * 3 + k) * n + j] * 255;
+		}
+		fz_drawtriangle(temp, tri[0], tri[1], tri[2], n);
+baddata:
+		;
+	}
+
+	if (shade->usefunction)
+	{
+		for (i = 0; i < 256; i++)
+		{
+			fz_convertcolor(shade->cs, shade->function[i], destcs, rgb);
+			clut[i][0] = rgb[0] * 255;
+			clut[i][1] = rgb[1] * 255;
+			clut[i][2] = rgb[2] * 255;
+		}
+
+		n = temp->w * temp->h;
+		s = temp->samples;
+		d = dest->samples;
+
+		while (n--)
+		{
+			d[0] = s[0];
+			d[1] = fz_mul255(s[0], clut[s[1]][0]);
+			d[2] = fz_mul255(s[0], clut[s[1]][1]);
+			d[3] = fz_mul255(s[0], clut[s[1]][2]);
+			s += 2;
+			d += 4;
+		}
+
+		fz_freepixmap(temp);
+	}
+
+	else if (shade->cs != destcs)
+	{
+		fz_convertpixmap(shade->cs, temp, destcs, dest);
+		fz_freepixmap(temp);
+	}
+}
+