X-Git-Url: http://git.asbjorn.biz/?a=blobdiff_plain;f=lib%2Fart%2Fart_render_gradient.c;fp=lib%2Fart%2Fart_render_gradient.c;h=e58fff0bccb5fb3fe4ce0d90f3f5ab1b5c6895cb;hb=418ef05b5d0b74e6f19200ffa40bcc3afccb5029;hp=0000000000000000000000000000000000000000;hpb=c1f4a906117e98e2f4ba59abc1ce153e8129bc19;p=swftools.git diff --git a/lib/art/art_render_gradient.c b/lib/art/art_render_gradient.c new file mode 100644 index 0000000..e58fff0 --- /dev/null +++ b/lib/art/art_render_gradient.c @@ -0,0 +1,716 @@ +/* + * art_render_gradient.c: Gradient image source for modular rendering. + * + * Libart_LGPL - library of basic graphic primitives + * Copyright (C) 2000 Raph Levien + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + * Authors: Raph Levien + * Alexander Larsson + */ + +#include "config.h" +#include "art_render_gradient.h" + +#include +#include +#include +#include +#include + +/* Hack to find out how to define alloca on different platforms. + * Modified version of glib/galloca.h. + */ + +#ifdef __GNUC__ +/* GCC does the right thing */ +# undef alloca +# define alloca(size) __builtin_alloca (size) +#elif defined (HAVE_ALLOCA_H) +/* a native and working alloca.h is there */ +# include +#else /* !__GNUC__ && !HAVE_ALLOCA_H */ +# ifdef _MSC_VER +# include +# define alloca _alloca +# else /* !_MSC_VER */ +# ifdef _AIX + #pragma alloca +# else /* !_AIX */ +# ifndef alloca /* predefined by HP cc +Olibcalls */ +char *alloca (); +# endif /* !alloca */ +# endif /* !_AIX */ +# endif /* !_MSC_VER */ +#endif /* !__GNUC__ && !HAVE_ALLOCA_H */ + +#undef DEBUG_SPEW + +typedef struct _ArtImageSourceGradLin ArtImageSourceGradLin; +typedef struct _ArtImageSourceGradRad ArtImageSourceGradRad; + +/* The stops will be copied right after this structure */ +struct _ArtImageSourceGradLin { + ArtImageSource super; + ArtGradientLinear gradient; + ArtGradientStop stops[1]; +}; + +/* The stops will be copied right after this structure */ +struct _ArtImageSourceGradRad { + ArtImageSource super; + ArtGradientRadial gradient; + double a; + ArtGradientStop stops[1]; +}; + +#define EPSILON 1e-6 + +#ifndef MAX +#define MAX(a, b) (((a) > (b)) ? (a) : (b)) +#endif /* MAX */ + +#ifndef MIN +#define MIN(a, b) (((a) < (b)) ? (a) : (b)) +#endif /* MIN */ + +static void +art_rgba_gradient_run (art_u8 *buf, + art_u8 *color1, + art_u8 *color2, + int len) +{ + int i; + int r, g, b, a; + int dr, dg, db, da; + +#ifdef DEBUG_SPEW + printf ("gradient run from %3d %3d %3d %3d to %3d %3d %3d %3d in %d pixels\n", + color1[0], color1[1], color1[2], color1[3], + color2[0], color2[1], color2[2], color2[3], + len); +#endif + + r = (color1[0] << 16) + 0x8000; + g = (color1[1] << 16) + 0x8000; + b = (color1[2] << 16) + 0x8000; + a = (color1[3] << 16) + 0x8000; + dr = ((color2[0] - color1[0]) << 16) / len; + dg = ((color2[1] - color1[1]) << 16) / len; + db = ((color2[2] - color1[2]) << 16) / len; + da = ((color2[3] - color1[3]) << 16) / len; + + for (i = 0; i < len; i++) + { + *buf++ = (r>>16); + *buf++ = (g>>16); + *buf++ = (b>>16); + *buf++ = (a>>16); + + r += dr; + g += dg; + b += db; + a += da; + } +} + +static void +calc_color_at (ArtGradientStop *stops, + int n_stops, + ArtGradientSpread spread, + double offset, + double offset_fraction, + int favor_start, + int ix, + art_u8 *color) +{ + double off0, off1; + int j; + + if (spread == ART_GRADIENT_PAD) + { + if (offset < 0.0) + { + color[0] = ART_PIX_8_FROM_MAX (stops[0].color[0]); + color[1] = ART_PIX_8_FROM_MAX (stops[0].color[1]); + color[2] = ART_PIX_8_FROM_MAX (stops[0].color[2]); + color[3] = ART_PIX_8_FROM_MAX (stops[0].color[3]); + return; + } + if (offset >= 1.0) + { + color[0] = ART_PIX_8_FROM_MAX (stops[n_stops-1].color[0]); + color[1] = ART_PIX_8_FROM_MAX (stops[n_stops-1].color[1]); + color[2] = ART_PIX_8_FROM_MAX (stops[n_stops-1].color[2]); + color[3] = ART_PIX_8_FROM_MAX (stops[n_stops-1].color[3]); + return; + } + } + + if (ix > 0 && ix < n_stops) + { + off0 = stops[ix - 1].offset; + off1 = stops[ix].offset; + if (fabs (off1 - off0) > EPSILON) + { + double interp; + double o; + o = offset_fraction; + + if ((fabs (o) < EPSILON) && (!favor_start)) + o = 1.0; + else if ((fabs (o-1.0) < EPSILON) && (favor_start)) + o = 0.0; + + /* + if (offset_fraction == 0.0 && !favor_start) + offset_fraction = 1.0; + */ + + interp = (o - off0) / (off1 - off0); + for (j = 0; j < 4; j++) + { + int z0, z1; + int z; + z0 = stops[ix - 1].color[j]; + z1 = stops[ix].color[j]; + z = floor (z0 + (z1 - z0) * interp + 0.5); + color[j] = ART_PIX_8_FROM_MAX (z); + } + return; + } + /* If offsets are too close to safely do the division, just + pick the ix color. */ + color[0] = ART_PIX_8_FROM_MAX (stops[ix].color[0]); + color[1] = ART_PIX_8_FROM_MAX (stops[ix].color[1]); + color[2] = ART_PIX_8_FROM_MAX (stops[ix].color[2]); + color[3] = ART_PIX_8_FROM_MAX (stops[ix].color[3]); + return; + } + + printf ("WARNING! bad ix %d in calc_color_at() [internal error]\n", ix); + assert (0); +} + +static void +art_render_gradient_linear_render_8 (ArtRenderCallback *self, + ArtRender *render, + art_u8 *dest, int y) +{ + ArtImageSourceGradLin *z = (ArtImageSourceGradLin *)self; + const ArtGradientLinear *gradient = &(z->gradient); + int i; + int width = render->x1 - render->x0; + int len; + double offset, d_offset; + double offset_fraction; + int next_stop; + int ix; + art_u8 color1[4], color2[4]; + int n_stops = gradient->n_stops; + int extra_stops; + ArtGradientStop *stops = gradient->stops; + ArtGradientStop *tmp_stops; + art_u8 *bufp = render->image_buf; + ArtGradientSpread spread = gradient->spread; + +#ifdef DEBUG_SPEW + printf ("x1: %d, x2: %d, y: %d\n", render->x0, render->x1, y); + printf ("spread: %d, stops:", gradient->spread); + for (i=0;istops[i].offset); + } + printf ("\n"); + printf ("a: %f, b: %f, c: %f\n", gradient->a, gradient->b, gradient->c); +#endif + + offset = render->x0 * gradient->a + y * gradient->b + gradient->c; + d_offset = gradient->a; + + /* We need to force the gradient to extend the whole 0..1 segment, + because the rest of the code doesn't handle partial gradients + correctly */ + if ((gradient->stops[0].offset > EPSILON /* == 0.0 */) || + (gradient->stops[n_stops-1].offset < (1.0 - EPSILON))) + { + extra_stops = 0; + tmp_stops = stops = alloca (sizeof (ArtGradientStop) * (n_stops + 2)); + if (gradient->stops[0].offset > EPSILON /* 0.0 */) + { + memcpy (tmp_stops, gradient->stops, sizeof (ArtGradientStop)); + tmp_stops[0].offset = 0.0; + tmp_stops += 1; + extra_stops++; + } + memcpy (tmp_stops, gradient->stops, sizeof (ArtGradientStop) * n_stops); + if (gradient->stops[n_stops-1].offset < (1.0 - EPSILON)) + { + tmp_stops += n_stops; + memcpy (tmp_stops, &gradient->stops[n_stops-1], sizeof (ArtGradientStop)); + tmp_stops[0].offset = 1.0; + extra_stops++; + } + n_stops += extra_stops; + + +#ifdef DEBUG_SPEW + printf ("start/stop modified stops:"); + for (i=0;i offset_fraction || + (d_offset < 0.0 && fabs (stops[ix].offset - offset_fraction) < EPSILON)) + break; + if (ix == 0) + ix = n_stops - 1; + else if (ix == n_stops) + ix = n_stops - 1; + +#ifdef DEBUG_SPEW + printf ("Initial ix: %d\n", ix); +#endif + + assert (ix > 0); + assert (ix < n_stops); + assert ((stops[ix-1].offset <= offset_fraction + EPSILON) || + ((stops[ix].offset > (1.0 - EPSILON)) && (offset_fraction < EPSILON /* == 0.0*/))); + assert (offset_fraction <= stops[ix].offset); + /* FIXME: These asserts may be broken, it is for now + safer to not use them. Should be fixed! + See bug #121850 + assert ((offset_fraction != stops[ix-1].offset) || + (d_offset >= 0.0)); + assert ((offset_fraction != stops[ix].offset) || + (d_offset <= 0.0)); + */ + + while (width > 0) + { +#ifdef DEBUG_SPEW + printf ("ix: %d\n", ix); + printf ("start offset: %f\n", offset); +#endif + calc_color_at (stops, n_stops, + spread, + offset, + offset_fraction, + (d_offset > -EPSILON), + ix, + color1); + + if (d_offset > 0) + next_stop = ix; + else + next_stop = ix-1; + +#ifdef DEBUG_SPEW + printf ("next_stop: %d\n", next_stop); +#endif + if (fabs (d_offset) > EPSILON) + { + double o; + o = offset_fraction; + + if ((fabs (o) <= EPSILON) && (ix == n_stops - 1)) + o = 1.0; + else if ((fabs (o-1.0) <= EPSILON) && (ix == 1)) + o = 0.0; + +#ifdef DEBUG_SPEW + printf ("o: %f\n", o); +#endif + len = (int)floor (fabs ((stops[next_stop].offset - o) / d_offset)) + 1; + len = MAX (len, 0); + len = MIN (len, width); + } + else + { + len = width; + } +#ifdef DEBUG_SPEW + printf ("len: %d\n", len); +#endif + if (len > 0) + { + offset = offset + (len-1) * d_offset; + offset_fraction = offset - floor (offset); +#ifdef DEBUG_SPEW + printf ("end offset: %f, fraction: %f\n", offset, offset_fraction); +#endif + calc_color_at (stops, n_stops, + spread, + offset, + offset_fraction, + (d_offset < EPSILON), + ix, + color2); + + art_rgba_gradient_run (bufp, + color1, + color2, + len); + offset += d_offset; + offset_fraction = offset - floor (offset); + } + + if (d_offset > 0) + { + do + { + ix++; + if (ix == n_stops) + ix = 1; + /* Note: offset_fraction can actually be one here on x86 machines that + does calculations with extended precision, but later rounds to 64bit. + This happens if the 80bit offset_fraction is larger than the + largest 64bit double that is less than one. + */ + } + while (!((stops[ix-1].offset <= offset_fraction && + offset_fraction < stops[ix].offset) || + (ix == 1 && offset_fraction > (1.0 - EPSILON)))); + } + else + { + do + { + ix--; + if (ix == 0) + ix = n_stops - 1; + } + while (!((stops[ix-1].offset < offset_fraction && + offset_fraction <= stops[ix].offset) || + (ix == n_stops - 1 && offset_fraction < EPSILON /* == 0.0*/))); + } + + bufp += 4*len; + width -= len; + } +} + + +/** + * art_render_gradient_setpix: Set a gradient pixel. + * @render: The render object. + * @dst: Pointer to destination (where to store pixel). + * @n_stops: Number of stops in @stops. + * @stops: The stops for the gradient. + * @offset: The offset. + * + * @n_stops must be > 0. + * + * Sets a gradient pixel, storing it at @dst. + **/ +static void +art_render_gradient_setpix (ArtRender *render, + art_u8 *dst, + int n_stops, ArtGradientStop *stops, + double offset) +{ + int ix; + int j; + double off0, off1; + int n_ch = render->n_chan + 1; + + for (ix = 0; ix < n_stops; ix++) + if (stops[ix].offset > offset) + break; + /* stops[ix - 1].offset < offset < stops[ix].offset */ + if (ix > 0 && ix < n_stops) + { + off0 = stops[ix - 1].offset; + off1 = stops[ix].offset; + if (fabs (off1 - off0) > EPSILON) + { + double interp; + + interp = (offset - off0) / (off1 - off0); + for (j = 0; j < n_ch; j++) + { + int z0, z1; + int z; + z0 = stops[ix - 1].color[j]; + z1 = stops[ix].color[j]; + z = floor (z0 + (z1 - z0) * interp + 0.5); + if (render->buf_depth == 8) + dst[j] = ART_PIX_8_FROM_MAX (z); + else /* (render->buf_depth == 16) */ + ((art_u16 *)dst)[j] = z; + } + return; + } + } + else if (ix == n_stops) + ix--; + + for (j = 0; j < n_ch; j++) + { + int z; + z = stops[ix].color[j]; + if (render->buf_depth == 8) + dst[j] = ART_PIX_8_FROM_MAX (z); + else /* (render->buf_depth == 16) */ + ((art_u16 *)dst)[j] = z; + } +} + +static void +art_render_gradient_linear_done (ArtRenderCallback *self, ArtRender *render) +{ + art_free (self); +} + +static void +art_render_gradient_linear_render (ArtRenderCallback *self, ArtRender *render, + art_u8 *dest, int y) +{ + ArtImageSourceGradLin *z = (ArtImageSourceGradLin *)self; + const ArtGradientLinear *gradient = &(z->gradient); + int pixstride = (render->n_chan + 1) * (render->depth >> 3); + int x; + int width = render->x1 - render->x0; + double offset, d_offset; + double actual_offset; + int n_stops = gradient->n_stops; + ArtGradientStop *stops = gradient->stops; + art_u8 *bufp = render->image_buf; + ArtGradientSpread spread = gradient->spread; + + offset = render->x0 * gradient->a + y * gradient->b + gradient->c; + d_offset = gradient->a; + + for (x = 0; x < width; x++) + { + if (spread == ART_GRADIENT_PAD) + actual_offset = offset; + else if (spread == ART_GRADIENT_REPEAT) + actual_offset = offset - floor (offset); + else /* (spread == ART_GRADIENT_REFLECT) */ + { + double tmp; + + tmp = offset - 2 * floor (0.5 * offset); + actual_offset = tmp > 1 ? 2 - tmp : tmp; + } + art_render_gradient_setpix (render, bufp, n_stops, stops, actual_offset); + offset += d_offset; + bufp += pixstride; + } +} + +static void +art_render_gradient_linear_negotiate (ArtImageSource *self, ArtRender *render, + ArtImageSourceFlags *p_flags, + int *p_buf_depth, ArtAlphaType *p_alpha) +{ + if (render->depth == 8 && + render->n_chan == 3) + { + self->super.render = art_render_gradient_linear_render_8; + *p_flags = 0; + *p_buf_depth = 8; + *p_alpha = ART_ALPHA_PREMUL; + return; + } + + self->super.render = art_render_gradient_linear_render; + *p_flags = 0; + *p_buf_depth = render->depth; + *p_alpha = ART_ALPHA_PREMUL; +} + +/** + * art_render_gradient_linear: Add a linear gradient image source. + * @render: The render object. + * @gradient: The linear gradient. + * + * Adds the linear gradient @gradient as the image source for rendering + * in the render object @render. + **/ +void +art_render_gradient_linear (ArtRender *render, + const ArtGradientLinear *gradient, + ArtFilterLevel level) +{ + ArtImageSourceGradLin *image_source = art_alloc (sizeof (ArtImageSourceGradLin) + + sizeof (ArtGradientStop) * (gradient->n_stops - 1)); + + image_source->super.super.render = NULL; + image_source->super.super.done = art_render_gradient_linear_done; + image_source->super.negotiate = art_render_gradient_linear_negotiate; + + /* copy the gradient into the structure */ + image_source->gradient = *gradient; + image_source->gradient.stops = image_source->stops; + memcpy (image_source->gradient.stops, gradient->stops, sizeof (ArtGradientStop) * gradient->n_stops); + + art_render_add_image_source (render, &image_source->super); +} + +static void +art_render_gradient_radial_done (ArtRenderCallback *self, ArtRender *render) +{ + art_free (self); +} + +static void +art_render_gradient_radial_render (ArtRenderCallback *self, ArtRender *render, + art_u8 *dest, int y) +{ + ArtImageSourceGradRad *z = (ArtImageSourceGradRad *)self; + const ArtGradientRadial *gradient = &(z->gradient); + int pixstride = (render->n_chan + 1) * (render->depth >> 3); + int x; + int x0 = render->x0; + int width = render->x1 - x0; + int n_stops = gradient->n_stops; + ArtGradientStop *stops = gradient->stops; + art_u8 *bufp = render->image_buf; + double fx = gradient->fx; + double fy = gradient->fy; + double dx, dy; + double *affine = gradient->affine; + double aff0 = affine[0]; + double aff1 = affine[1]; + const double a = z->a; + const double arecip = 1.0 / a; + double b, db; + double c, dc, ddc; + double b_a, db_a; + double rad, drad, ddrad; + + dx = x0 * aff0 + y * affine[2] + affine[4] - fx; + dy = x0 * aff1 + y * affine[3] + affine[5] - fy; + b = dx * fx + dy * fy; + db = aff0 * fx + aff1 * fy; + c = dx * dx + dy * dy; + dc = 2 * aff0 * dx + aff0 * aff0 + 2 * aff1 * dy + aff1 * aff1; + ddc = 2 * aff0 * aff0 + 2 * aff1 * aff1; + + b_a = b * arecip; + db_a = db * arecip; + + rad = b_a * b_a + c * arecip; + drad = 2 * b_a * db_a + db_a * db_a + dc * arecip; + ddrad = 2 * db_a * db_a + ddc * arecip; + + for (x = 0; x < width; x++) + { + double z; + + if (rad > 0) + z = b_a + sqrt (rad); + else + z = b_a; + art_render_gradient_setpix (render, bufp, n_stops, stops, z); + bufp += pixstride; + b_a += db_a; + rad += drad; + drad += ddrad; + } +} + +static void +art_render_gradient_radial_negotiate (ArtImageSource *self, ArtRender *render, + ArtImageSourceFlags *p_flags, + int *p_buf_depth, ArtAlphaType *p_alpha) +{ + self->super.render = art_render_gradient_radial_render; + *p_flags = 0; + *p_buf_depth = render->depth; + *p_alpha = ART_ALPHA_PREMUL; +} + +/** + * art_render_gradient_radial: Add a radial gradient image source. + * @render: The render object. + * @gradient: The radial gradient. + * + * Adds the radial gradient @gradient as the image source for rendering + * in the render object @render. + **/ +void +art_render_gradient_radial (ArtRender *render, + const ArtGradientRadial *gradient, + ArtFilterLevel level) +{ + ArtImageSourceGradRad *image_source = art_alloc (sizeof (ArtImageSourceGradRad) + + sizeof (ArtGradientStop) * (gradient->n_stops - 1)); + double fx = gradient->fx; + double fy = gradient->fy; + + image_source->super.super.render = NULL; + image_source->super.super.done = art_render_gradient_radial_done; + image_source->super.negotiate = art_render_gradient_radial_negotiate; + + /* copy the gradient into the structure */ + image_source->gradient = *gradient; + image_source->gradient.stops = image_source->stops; + memcpy (image_source->gradient.stops, gradient->stops, sizeof (ArtGradientStop) * gradient->n_stops); + + /* todo: sanitycheck fx, fy? */ + image_source->a = 1 - fx * fx - fy * fy; + + art_render_add_image_source (render, &image_source->super); +}