575 lines
12 KiB
C
575 lines
12 KiB
C
#include "fitz.h"
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/*
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* polygon clipping
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*/
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enum { IN, OUT, ENTER, LEAVE };
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enum { MAXV = 3 + 4 };
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enum { MAXN = 2 + FZ_MAX_COLORS };
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static int clipx(float val, int ismax, float *v1, float *v2, int n)
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{
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float t;
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int i;
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int v1o = ismax ? v1[0] > val : v1[0] < val;
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int v2o = ismax ? v2[0] > val : v2[0] < val;
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if (v1o + v2o == 0)
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return IN;
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if (v1o + v2o == 2)
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return OUT;
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if (v2o)
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{
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t = (val - v1[0]) / (v2[0] - v1[0]);
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v2[0] = val;
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v2[1] = v1[1] + t * (v2[1] - v1[1]);
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for (i = 2; i < n; i++)
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v2[i] = v1[i] + t * (v2[i] - v1[i]);
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return LEAVE;
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}
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else
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{
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t = (val - v2[0]) / (v1[0] - v2[0]);
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v1[0] = val;
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v1[1] = v2[1] + t * (v1[1] - v2[1]);
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for (i = 2; i < n; i++)
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v1[i] = v2[i] + t * (v1[i] - v2[i]);
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return ENTER;
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}
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}
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static int clipy(float val, int ismax, float *v1, float *v2, int n)
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{
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float t;
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int i;
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int v1o = ismax ? v1[1] > val : v1[1] < val;
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int v2o = ismax ? v2[1] > val : v2[1] < val;
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if (v1o + v2o == 0)
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return IN;
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if (v1o + v2o == 2)
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return OUT;
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if (v2o)
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{
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t = (val - v1[1]) / (v2[1] - v1[1]);
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v2[0] = v1[0] + t * (v2[0] - v1[0]);
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v2[1] = val;
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for (i = 2; i < n; i++)
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v2[i] = v1[i] + t * (v2[i] - v1[i]);
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return LEAVE;
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}
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else
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{
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t = (val - v2[1]) / (v1[1] - v2[1]);
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v1[0] = v2[0] + t * (v1[0] - v2[0]);
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v1[1] = val;
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for (i = 2; i < n; i++)
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v1[i] = v2[i] + t * (v1[i] - v2[i]);
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return ENTER;
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}
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}
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static inline void copy_vert(float *dst, float *src, int n)
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{
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while (n--)
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*dst++ = *src++;
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}
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static int clip_poly(float src[MAXV][MAXN],
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float dst[MAXV][MAXN], int len, int n,
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float val, int isy, int ismax)
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{
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float cv1[MAXN];
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float cv2[MAXN];
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int v1, v2, cp;
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int r;
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v1 = len - 1;
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cp = 0;
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for (v2 = 0; v2 < len; v2++)
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{
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copy_vert(cv1, src[v1], n);
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copy_vert(cv2, src[v2], n);
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if (isy)
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r = clipy(val, ismax, cv1, cv2, n);
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else
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r = clipx(val, ismax, cv1, cv2, n);
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switch (r)
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{
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case IN:
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copy_vert(dst[cp++], cv2, n);
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break;
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case OUT:
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break;
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case LEAVE:
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copy_vert(dst[cp++], cv2, n);
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break;
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case ENTER:
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copy_vert(dst[cp++], cv1, n);
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copy_vert(dst[cp++], cv2, n);
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break;
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}
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v1 = v2;
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}
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return cp;
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}
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/*
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* gouraud shaded polygon scan conversion
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*/
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static void paint_scan(fz_pixmap *pix, int y, int x1, int x2, int *v1, int *v2, int n)
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{
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unsigned char *p = pix->samples + ((y - pix->y) * pix->w + (x1 - pix->x)) * pix->n;
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int v[FZ_MAX_COLORS];
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int dv[FZ_MAX_COLORS];
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int w = x2 - x1;
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int k;
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assert(w >= 0);
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assert(y >= pix->y);
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assert(y < pix->y + pix->h);
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assert(x1 >= pix->x);
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assert(x2 <= pix->x + pix->w);
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if (w == 0)
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return;
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for (k = 0; k < n; k++)
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{
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v[k] = v1[k];
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dv[k] = (v2[k] - v1[k]) / w;
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}
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while (w--)
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{
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for (k = 0; k < n; k++)
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{
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*p++ = v[k] >> 16;
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v[k] += dv[k];
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}
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*p++ = 255;
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}
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}
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static int find_next(int gel[MAXV][MAXN], int len, int a, int *s, int *e, int d)
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{
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int b;
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while (1)
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{
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b = a + d;
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if (b == len)
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b = 0;
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if (b == -1)
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b = len - 1;
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if (gel[b][1] == gel[a][1])
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{
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a = b;
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continue;
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}
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if (gel[b][1] > gel[a][1])
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{
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*s = a;
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*e = b;
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return 0;
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}
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return 1;
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}
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}
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static void load_edge(int gel[MAXV][MAXN], int s, int e, int *ael, int *del, int n)
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{
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int swp, k, dy;
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if (gel[s][1] > gel[e][1])
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{
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swp = s; s = e; e = swp;
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}
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dy = gel[e][1] - gel[s][1];
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ael[0] = gel[s][0];
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del[0] = (gel[e][0] - gel[s][0]) / dy;
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for (k = 2; k < n; k++)
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{
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ael[k] = gel[s][k];
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del[k] = (gel[e][k] - gel[s][k]) / dy;
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}
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}
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static inline void step_edge(int *ael, int *del, int n)
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{
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int k;
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ael[0] += del[0];
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for (k = 2; k < n; k++)
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ael[k] += del[k];
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}
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static void
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fz_paint_triangle(fz_pixmap *pix, float *av, float *bv, float *cv, int n, fz_bbox bbox)
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{
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float poly[MAXV][MAXN];
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float temp[MAXV][MAXN];
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float cx0 = bbox.x0;
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float cy0 = bbox.y0;
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float cx1 = bbox.x1;
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float cy1 = bbox.y1;
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int gel[MAXV][MAXN];
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int ael[2][MAXN];
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int del[2][MAXN];
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int y, s0, s1, e0, e1;
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int top, bot, len;
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int i, k;
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copy_vert(poly[0], av, n);
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copy_vert(poly[1], bv, n);
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copy_vert(poly[2], cv, n);
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len = clip_poly(poly, temp, 3, n, cx0, 0, 0);
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len = clip_poly(temp, poly, len, n, cx1, 0, 1);
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len = clip_poly(poly, temp, len, n, cy0, 1, 0);
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len = clip_poly(temp, poly, len, n, cy1, 1, 1);
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if (len < 3)
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return;
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for (i = 0; i < len; i++)
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{
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gel[i][0] = floorf(poly[i][0] + 0.5f) * 65536; /* trunc and fix */
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gel[i][1] = floorf(poly[i][1] + 0.5f); /* y is not fixpoint */
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for (k = 2; k < n; k++)
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gel[i][k] = poly[i][k] * 65536; /* fix with precision */
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}
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top = bot = 0;
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for (i = 0; i < len; i++)
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{
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if (gel[i][1] < gel[top][1])
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top = i;
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if (gel[i][1] > gel[bot][1])
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bot = i;
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}
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if (gel[bot][1] - gel[top][1] == 0)
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return;
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y = gel[top][1];
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if (find_next(gel, len, top, &s0, &e0, 1))
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return;
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if (find_next(gel, len, top, &s1, &e1, -1))
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return;
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load_edge(gel, s0, e0, ael[0], del[0], n);
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load_edge(gel, s1, e1, ael[1], del[1], n);
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while (1)
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{
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int x0 = ael[0][0] >> 16;
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int x1 = ael[1][0] >> 16;
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if (ael[0][0] < ael[1][0])
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paint_scan(pix, y, x0, x1, ael[0]+2, ael[1]+2, n-2);
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else
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paint_scan(pix, y, x1, x0, ael[1]+2, ael[0]+2, n-2);
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step_edge(ael[0], del[0], n);
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step_edge(ael[1], del[1], n);
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y ++;
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if (y >= gel[e0][1])
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{
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if (find_next(gel, len, e0, &s0, &e0, 1))
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return;
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load_edge(gel, s0, e0, ael[0], del[0], n);
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}
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if (y >= gel[e1][1])
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{
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if (find_next(gel, len, e1, &s1, &e1, -1))
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return;
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load_edge(gel, s1, e1, ael[1], del[1], n);
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}
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}
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}
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static void
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fz_paint_quad(fz_pixmap *pix,
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fz_point p0, fz_point p1, fz_point p2, fz_point p3,
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float c0, float c1, float c2, float c3,
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int n, fz_bbox bbox)
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{
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float v[4][3];
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v[0][0] = p0.x;
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v[0][1] = p0.y;
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v[0][2] = c0;
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v[1][0] = p1.x;
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v[1][1] = p1.y;
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v[1][2] = c1;
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v[2][0] = p2.x;
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v[2][1] = p2.y;
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v[2][2] = c2;
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v[3][0] = p3.x;
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v[3][1] = p3.y;
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v[3][2] = c3;
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fz_paint_triangle(pix, v[0], v[2], v[3], n, bbox);
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fz_paint_triangle(pix, v[0], v[3], v[1], n, bbox);
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}
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/*
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* linear, radial and mesh painting
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*/
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#define HUGENUM 32000 /* how far to extend axial/radial shadings */
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#define RADSEGS 32 /* how many segments to generate for radial meshes */
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static fz_point
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fz_point_on_circle(fz_point p, float r, float theta)
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{
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p.x = p.x + cosf(theta) * r;
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p.y = p.y + sinf(theta) * r;
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return p;
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}
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static void
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fz_paint_linear(fz_shade *shade, fz_matrix ctm, fz_pixmap *dest, fz_bbox bbox)
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{
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fz_point p0, p1;
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fz_point v0, v1, v2, v3;
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fz_point e0, e1;
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float theta;
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p0.x = shade->mesh[0];
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p0.y = shade->mesh[1];
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p0 = fz_transform_point(ctm, p0);
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p1.x = shade->mesh[3];
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p1.y = shade->mesh[4];
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p1 = fz_transform_point(ctm, p1);
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theta = atan2f(p1.y - p0.y, p1.x - p0.x);
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theta += (float)M_PI * 0.5f;
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v0 = fz_point_on_circle(p0, HUGENUM, theta);
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v1 = fz_point_on_circle(p1, HUGENUM, theta);
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v2 = fz_point_on_circle(p0, -HUGENUM, theta);
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v3 = fz_point_on_circle(p1, -HUGENUM, theta);
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fz_paint_quad(dest, v0, v1, v2, v3, 0, 255, 0, 255, 3, bbox);
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if (shade->extend[0])
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{
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e0.x = v0.x - (p1.x - p0.x) * HUGENUM;
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e0.y = v0.y - (p1.y - p0.y) * HUGENUM;
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e1.x = v2.x - (p1.x - p0.x) * HUGENUM;
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e1.y = v2.y - (p1.y - p0.y) * HUGENUM;
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fz_paint_quad(dest, e0, e1, v0, v2, 0, 0, 0, 0, 3, bbox);
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}
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if (shade->extend[1])
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{
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e0.x = v1.x + (p1.x - p0.x) * HUGENUM;
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e0.y = v1.y + (p1.y - p0.y) * HUGENUM;
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e1.x = v3.x + (p1.x - p0.x) * HUGENUM;
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e1.y = v3.y + (p1.y - p0.y) * HUGENUM;
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fz_paint_quad(dest, e0, e1, v1, v3, 255, 255, 255, 255, 3, bbox);
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}
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}
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static void
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fz_paint_annulus(fz_matrix ctm,
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fz_point p0, float r0, float c0,
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fz_point p1, float r1, float c1,
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fz_pixmap *dest, fz_bbox bbox)
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{
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fz_point t0, t1, t2, t3, b0, b1, b2, b3;
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float theta, step;
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int i;
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theta = atan2f(p1.y - p0.y, p1.x - p0.x);
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step = (float)M_PI * 2 / RADSEGS;
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for (i = 0; i < RADSEGS / 2; i++)
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{
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t0 = fz_point_on_circle(p0, r0, theta + i * step);
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t1 = fz_point_on_circle(p0, r0, theta + i * step + step);
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t2 = fz_point_on_circle(p1, r1, theta + i * step);
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t3 = fz_point_on_circle(p1, r1, theta + i * step + step);
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b0 = fz_point_on_circle(p0, r0, theta - i * step);
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b1 = fz_point_on_circle(p0, r0, theta - i * step - step);
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b2 = fz_point_on_circle(p1, r1, theta - i * step);
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b3 = fz_point_on_circle(p1, r1, theta - i * step - step);
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t0 = fz_transform_point(ctm, t0);
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t1 = fz_transform_point(ctm, t1);
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t2 = fz_transform_point(ctm, t2);
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t3 = fz_transform_point(ctm, t3);
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b0 = fz_transform_point(ctm, b0);
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b1 = fz_transform_point(ctm, b1);
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b2 = fz_transform_point(ctm, b2);
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b3 = fz_transform_point(ctm, b3);
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fz_paint_quad(dest, t0, t1, t2, t3, c0, c0, c1, c1, 3, bbox);
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fz_paint_quad(dest, b0, b1, b2, b3, c0, c0, c1, c1, 3, bbox);
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}
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}
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static void
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fz_paint_radial(fz_shade *shade, fz_matrix ctm, fz_pixmap *dest, fz_bbox bbox)
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{
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fz_point p0, p1;
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float r0, r1;
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fz_point e;
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float er, rs;
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p0.x = shade->mesh[0];
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p0.y = shade->mesh[1];
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r0 = shade->mesh[2];
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p1.x = shade->mesh[3];
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p1.y = shade->mesh[4];
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r1 = shade->mesh[5];
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if (shade->extend[0])
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{
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if (r0 < r1)
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rs = r0 / (r0 - r1);
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else
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rs = -HUGENUM;
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e.x = p0.x + (p1.x - p0.x) * rs;
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e.y = p0.y + (p1.y - p0.y) * rs;
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er = r0 + (r1 - r0) * rs;
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fz_paint_annulus(ctm, e, er, 0, p0, r0, 0, dest, bbox);
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}
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fz_paint_annulus(ctm, p0, r0, 0, p1, r1, 255, dest, bbox);
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if (shade->extend[1])
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{
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if (r0 > r1)
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rs = r1 / (r1 - r0);
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else
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rs = -HUGENUM;
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e.x = p1.x + (p0.x - p1.x) * rs;
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e.y = p1.y + (p0.y - p1.y) * rs;
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er = r1 + (r0 - r1) * rs;
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fz_paint_annulus(ctm, p1, r1, 255, e, er, 255, dest, bbox);
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}
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}
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static void
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fz_paint_mesh(fz_shade *shade, fz_matrix ctm, fz_pixmap *dest, fz_bbox bbox)
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{
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float tri[3][MAXN];
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fz_point p;
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float *mesh;
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int ntris;
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int i, k;
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|
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mesh = shade->mesh;
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|
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if (shade->use_function)
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ntris = shade->mesh_len / 9;
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else
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ntris = shade->mesh_len / ((2 + shade->colorspace->n) * 3);
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|
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while (ntris--)
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{
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for (k = 0; k < 3; k++)
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{
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p.x = *mesh++;
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p.y = *mesh++;
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p = fz_transform_point(ctm, p);
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tri[k][0] = p.x;
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tri[k][1] = p.y;
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if (shade->use_function)
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tri[k][2] = *mesh++ * 255;
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else
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{
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fz_convert_color(shade->colorspace, mesh, dest->colorspace, tri[k] + 2);
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for (i = 0; i < dest->colorspace->n; i++)
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tri[k][i + 2] *= 255;
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mesh += shade->colorspace->n;
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|
}
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|
}
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|
fz_paint_triangle(dest, tri[0], tri[1], tri[2], 2 + dest->colorspace->n, bbox);
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|
}
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|
}
|
|
|
|
void
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|
fz_paint_shade(fz_shade *shade, fz_matrix ctm, fz_pixmap *dest, fz_bbox bbox)
|
|
{
|
|
unsigned char clut[256][FZ_MAX_COLORS];
|
|
fz_pixmap *temp, *conv;
|
|
float color[FZ_MAX_COLORS];
|
|
int i, k;
|
|
|
|
ctm = fz_concat(shade->matrix, ctm);
|
|
|
|
if (shade->use_function)
|
|
{
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
fz_convert_color(shade->colorspace, shade->function[i], dest->colorspace, color);
|
|
for (k = 0; k < dest->colorspace->n; k++)
|
|
clut[i][k] = color[k] * 255;
|
|
clut[i][k] = shade->function[i][shade->colorspace->n] * 255;
|
|
}
|
|
conv = fz_new_pixmap_with_rect(dest->colorspace, bbox);
|
|
temp = fz_new_pixmap_with_rect(fz_device_gray, bbox);
|
|
fz_clear_pixmap(temp);
|
|
}
|
|
else
|
|
{
|
|
temp = dest;
|
|
}
|
|
|
|
switch (shade->type)
|
|
{
|
|
case FZ_LINEAR: fz_paint_linear(shade, ctm, temp, bbox); break;
|
|
case FZ_RADIAL: fz_paint_radial(shade, ctm, temp, bbox); break;
|
|
case FZ_MESH: fz_paint_mesh(shade, ctm, temp, bbox); break;
|
|
}
|
|
|
|
if (shade->use_function)
|
|
{
|
|
unsigned char *s = temp->samples;
|
|
unsigned char *d = conv->samples;
|
|
int len = temp->w * temp->h;
|
|
while (len--)
|
|
{
|
|
int v = *s++;
|
|
int a = fz_mul255(*s++, clut[v][conv->n - 1]);
|
|
for (k = 0; k < conv->n - 1; k++)
|
|
*d++ = fz_mul255(clut[v][k], a);
|
|
*d++ = a;
|
|
}
|
|
fz_paint_pixmap(dest, conv, 255);
|
|
fz_drop_pixmap(conv);
|
|
fz_drop_pixmap(temp);
|
|
}
|
|
}
|