eBookReaderSwitch/mupdf/source/fitz/draw-mesh.c

395 lines
8.9 KiB
C

#include "mupdf/fitz.h"
#include "draw-imp.h"
#include <assert.h>
#include <math.h>
enum { MAXN = 2 + FZ_MAX_COLORS };
static void paint_scan(fz_pixmap *FZ_RESTRICT pix, int y, int fx0, int fx1, int cx0, int cx1, const int *FZ_RESTRICT v0, const int *FZ_RESTRICT v1, int n)
{
unsigned char *p;
int c[MAXN], dc[MAXN];
int k, w;
float div, mul;
int x0, x1, pa;
/* Ensure that fx0 is left edge, and fx1 is right */
if (fx0 > fx1)
{
const int *v;
int t = fx0; fx0 = fx1; fx1 = t;
v = v0; v0 = v1; v1 = v;
}
else if (fx0 == fx1)
return;
/* Clip fx0, fx1 to range */
if (fx0 >= cx1)
return;
if (fx1 <= cx0)
return;
x0 = (fx0 > cx0 ? fx0 : cx0);
x1 = (fx1 < cx1 ? fx1 : cx1);
w = x1 - x0;
if (w == 0)
return;
div = 1.0f / (fx1 - fx0);
mul = (x0 - fx0);
for (k = 0; k < n; k++)
{
dc[k] = (v1[k] - v0[k]) * div;
c[k] = v0[k] + dc[k] * mul;
}
p = pix->samples + ((x0 - pix->x) * pix->n) + ((y - pix->y) * pix->stride);
pa = pix->alpha;
do
{
for (k = 0; k < n; k++)
{
*p++ = c[k]>>16;
c[k] += dc[k];
}
if (pa)
*p++ = 255;
}
while (--w);
}
typedef struct edge_data_s edge_data;
struct edge_data_s
{
float x;
float dx;
int v[2*MAXN];
};
static inline void prepare_edge(const float *FZ_RESTRICT vtop, const float *FZ_RESTRICT vbot, edge_data *FZ_RESTRICT edge, float y, int n)
{
float r = 1.0f / (vbot[1] - vtop[1]);
float t = (y - vtop[1]) * r;
float diff = vbot[0] - vtop[0];
int i;
edge->x = vtop[0] + diff * t;
edge->dx = diff * r;
for (i = 0; i < n; i++)
{
diff = vbot[i+2] - vtop[i+2];
edge->v[i] = (int)(65536.0f * (vtop[i+2] + diff * t));
edge->v[i+MAXN] = (int)(65536.0f * diff * r);
}
}
static inline void step_edge(edge_data *edge, int n)
{
int i;
edge->x += edge->dx;
for (i = 0; i < n; i++)
{
edge->v[i] += edge->v[i + MAXN];
}
}
static void
fz_paint_triangle(fz_pixmap *pix, float *v[3], int n, fz_irect bbox)
{
edge_data e0, e1;
int top, mid, bot;
float y, y1;
int minx, maxx;
top = bot = 0;
if (v[1][1] < v[0][1]) top = 1; else bot = 1;
if (v[2][1] < v[top][1]) top = 2;
else if (v[2][1] > v[bot][1]) bot = 2;
if (v[top][1] == v[bot][1]) return;
/* Test if the triangle is completely outside the scissor rect */
if (v[bot][1] < bbox.y0) return;
if (v[top][1] > bbox.y1) return;
/* Magic! Ensure that mid/top/bot are all different */
mid = 3^top^bot;
assert(top != bot && top != mid && mid != bot);
minx = fz_maxi(bbox.x0, pix->x);
maxx = fz_mini(bbox.x1, pix->x + pix->w);
y = ceilf(fz_max(bbox.y0, v[top][1]));
y1 = ceilf(fz_min(bbox.y1, v[mid][1]));
n -= 2;
prepare_edge(v[top], v[bot], &e0, y, n);
if (y < y1)
{
prepare_edge(v[top], v[mid], &e1, y, n);
do
{
paint_scan(pix, y, (int)e0.x, (int)e1.x, minx, maxx, &e0.v[0], &e1.v[0], n);
step_edge(&e0, n);
step_edge(&e1, n);
y ++;
}
while (y < y1);
}
y1 = ceilf(fz_min(bbox.y1, v[bot][1]));
if (y < y1)
{
prepare_edge(v[mid], v[bot], &e1, y, n);
do
{
paint_scan(pix, y, (int)e0.x, (int)e1.x, minx, maxx, &e0.v[0], &e1.v[0], n);
y ++;
if (y >= y1)
break;
step_edge(&e0, n);
step_edge(&e1, n);
}
while (1);
}
}
struct paint_tri_data
{
const fz_shade *shade;
fz_pixmap *dest;
fz_irect bbox;
fz_color_converter cc;
};
static void
prepare_mesh_vertex(fz_context *ctx, void *arg, fz_vertex *v, const float *input)
{
struct paint_tri_data *ptd = (struct paint_tri_data *)arg;
const fz_shade *shade = ptd->shade;
fz_pixmap *dest = ptd->dest;
float *output = v->c;
int i;
if (shade->use_function)
output[0] = input[0] * 255;
else
{
int n = fz_colorspace_n(ctx, dest->colorspace);
int a = dest->alpha;
int m = dest->n - a;
if (ptd->cc.convert)
ptd->cc.convert(ctx, &ptd->cc, input, output);
for (i = 0; i < n; i++)
output[i] *= 255;
for (; i < m; i++)
output[i] = 0;
if (a)
output[i] = 255;
}
}
static void
do_paint_tri(fz_context *ctx, void *arg, fz_vertex *av, fz_vertex *bv, fz_vertex *cv)
{
struct paint_tri_data *ptd = (struct paint_tri_data *)arg;
float *vertices[3];
fz_pixmap *dest;
vertices[0] = (float *)av;
vertices[1] = (float *)bv;
vertices[2] = (float *)cv;
dest = ptd->dest;
fz_paint_triangle(dest, vertices, 2 + dest->n - dest->alpha, ptd->bbox);
}
/*
Render a shade to a given pixmap.
shade: The shade to paint.
override_cs: NULL, or colorspace to override the shades
inbuilt colorspace.
ctm: The transform to apply.
dest: The pixmap to render into.
color_params: The color rendering settings
bbox: Pointer to a bounding box to limit the rendering
of the shade.
op: NULL, or pointer to overprint bitmap.
*/
void
fz_paint_shade(fz_context *ctx, fz_shade *shade, fz_colorspace *colorspace, fz_matrix ctm, fz_pixmap *dest, fz_color_params color_params, fz_irect bbox, const fz_overprint *eop)
{
unsigned char clut[256][FZ_MAX_COLORS];
fz_pixmap *temp = NULL;
fz_pixmap *conv = NULL;
fz_color_converter cc = { 0 };
float color[FZ_MAX_COLORS];
struct paint_tri_data ptd = { 0 };
int i, k;
fz_matrix local_ctm;
fz_var(temp);
fz_var(conv);
if (colorspace == NULL)
colorspace = shade->colorspace;
fz_try(ctx)
{
local_ctm = fz_concat(shade->matrix, ctm);
if (shade->use_function)
{
/* We need to use alpha = 1 here, because the shade might not fill the bbox. */
temp = fz_new_pixmap_with_bbox(ctx, fz_device_gray(ctx), bbox, NULL, 1);
fz_clear_pixmap(ctx, temp);
}
else
{
temp = dest;
}
ptd.dest = temp;
ptd.shade = shade;
ptd.bbox = bbox;
if (temp->colorspace)
fz_init_cached_color_converter(ctx, &ptd.cc, colorspace, temp->colorspace, NULL, color_params);
fz_process_shade(ctx, shade, local_ctm, fz_rect_from_irect(bbox), prepare_mesh_vertex, &do_paint_tri, &ptd);
if (shade->use_function)
{
/* If the shade is defined in a deviceN (or separation,
* which is the same internally to MuPDF) space, then
* we need to render it in deviceN before painting it
* to the destination. If not, we are free to render it
* direct to the target. */
if (fz_colorspace_is_device_n(ctx, colorspace))
{
/* We've drawn it as greyscale, with the values being
* the input to the function. Now make DevN version
* by mapping that greyscale through the function.
* This seems inefficient, but it's actually required,
* because we need to apply the function lookup POST
* interpolation in the do_paint_tri routines, not
* before it to avoid problems with some test files
* (tests/GhentV3.0/061_Shading_x1a.pdf for example).
*/
unsigned char *s = temp->samples;
unsigned char *d;
int hh = temp->h;
int n = fz_colorspace_n(ctx, colorspace);
/* alpha = 1 here for the same reason as earlier */
conv = fz_new_pixmap_with_bbox(ctx, colorspace, bbox, NULL, 1);
d = conv->samples;
while (hh--)
{
int len = temp->w;
while (len--)
{
int v = *s++;
int a = *s++;
const float *f = shade->function[v];
for (k = 0; k < n; k++)
*d++ = fz_clampi(255 * f[k], 0, 255);
*d++ = a;
}
d += conv->stride - conv->w * conv->n;
s += temp->stride - temp->w * temp->n;
}
fz_drop_pixmap(ctx, temp);
temp = conv;
conv = NULL;
/* Now Change from our device_n colorspace into the target colorspace/spots. */
conv = fz_clone_pixmap_area_with_different_seps(ctx, temp, NULL, dest->colorspace, dest->seps, color_params, NULL);
}
else
{
unsigned char *s = temp->samples;
unsigned char *d;
int da;
int sa = temp->alpha;
int hh = temp->h;
int cn = fz_colorspace_n(ctx, colorspace);
int m = dest->n - dest->alpha;
int n = fz_colorspace_n(ctx, dest->colorspace);
if (dest->colorspace)
{
fz_find_color_converter(ctx, &cc, colorspace, dest->colorspace, NULL, color_params);
for (i = 0; i < 256; i++)
{
cc.convert(ctx, &cc, shade->function[i], color);
for (k = 0; k < n; k++)
clut[i][k] = color[k] * 255;
for (; k < m; k++)
clut[i][k] = 0;
clut[i][k] = shade->function[i][cn] * 255;
}
fz_drop_color_converter(ctx, &cc);
}
else
{
for (i = 0; i < 256; i++)
{
for (k = 0; k < m; k++)
clut[i][k] = 0;
clut[i][k] = shade->function[i][cn] * 255;
}
}
conv = fz_new_pixmap_with_bbox(ctx, dest->colorspace, bbox, dest->seps, 1);
d = conv->samples;
da = conv->alpha;
while (hh--)
{
int len = temp->w;
while (len--)
{
int v = *s++;
int a = (da ? clut[v][conv->n - 1] : 255);
if (sa)
a = fz_mul255(*s++, a);
for (k = 0; k < conv->n - da; k++)
*d++ = fz_mul255(clut[v][k], a);
if (da)
*d++ = a;
}
d += conv->stride - conv->w * conv->n;
s += temp->stride - temp->w * temp->n;
}
}
fz_paint_pixmap_with_overprint(dest, conv, eop);
}
}
fz_always(ctx)
{
if (shade->use_function)
{
fz_drop_color_converter(ctx, &cc);
fz_drop_pixmap(ctx, temp);
fz_drop_pixmap(ctx, conv);
}
fz_fin_cached_color_converter(ctx, &ptd.cc);
}
fz_catch(ctx)
fz_rethrow(ctx);
}