/* gradient.c - renders gradients
*
* Raster graphics library
*
* Copyright (c) 1997-2003 Alfredo K. Kojima
* Copyright (c) 1998-2003 Dan Pascu
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "wraster.h"
static RImage *renderHGradient(unsigned width, unsigned height,
int r0, int g0, int b0,
int rf, int gf, int bf);
static RImage *renderVGradient(unsigned width, unsigned height,
int r0, int g0, int b0,
int rf, int gf, int bf);
static RImage *renderDGradient(unsigned width, unsigned height,
int r0, int g0, int b0,
int rf, int gf, int bf);
static RImage *renderMHGradient(unsigned width, unsigned height,
RColor **colors, int count);
static RImage *renderMVGradient(unsigned width, unsigned height,
RColor **colors, int count);
static RImage *renderMDGradient(unsigned width, unsigned height,
RColor **colors, int count);
RImage*
RRenderMultiGradient(unsigned width, unsigned height, RColor **colors, int style)
{
int count;
count = 0;
while (colors[count]!=NULL) count++;
if (count > 2) {
switch (style) {
case RHorizontalGradient:
return renderMHGradient(width, height, colors, count);
case RVerticalGradient:
return renderMVGradient(width, height, colors, count);
case RDiagonalGradient:
return renderMDGradient(width, height, colors, count);
}
} else if (count > 1) {
return RRenderGradient(width, height, colors[0], colors[1], style);
} else if (count > 0) {
return RRenderGradient(width, height, colors[0], colors[0], style);
}
assert(0);
return NULL;
}
RImage*
RRenderGradient(unsigned width, unsigned height, RColor *from, RColor *to,
int style)
{
switch (style) {
case RHorizontalGradient:
return renderHGradient(width, height, from->red, from->green,
from->blue, to->red, to->green, to->blue);
case RVerticalGradient:
return renderVGradient(width, height, from->red, from->green,
from->blue, to->red, to->green, to->blue);
case RDiagonalGradient:
return renderDGradient(width, height, from->red, from->green,
from->blue, to->red, to->green, to->blue);
}
assert(0);
return NULL;
}
/*
*----------------------------------------------------------------------
* renderHGradient--
* Renders a horizontal linear gradient of the specified size in the
* RImage format with a border of the specified type.
*
* Returns:
* A 24bit RImage with the gradient (no alpha channel).
*
* Side effects:
* None
*----------------------------------------------------------------------
*/
static RImage*
renderHGradient(unsigned width, unsigned height, int r0, int g0, int b0,
int rf, int gf, int bf)
{
int i;
long r, g, b, dr, dg, db;
unsigned lineSize = width*3;
RImage *image;
unsigned char *ptr;
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
ptr = image->data;
r = r0 << 16;
g = g0 << 16;
b = b0 << 16;
dr = ((rf-r0)<<16)/(int)width;
dg = ((gf-g0)<<16)/(int)width;
db = ((bf-b0)<<16)/(int)width;
/* render the first line */
for (i=0; i<width; i++) {
*(ptr++) = (unsigned char)(r>>16);
*(ptr++) = (unsigned char)(g>>16);
*(ptr++) = (unsigned char)(b>>16);
r += dr;
g += dg;
b += db;
}
/* copy the first line to the other lines */
for (i=1; i<height; i++) {
memcpy(&(image->data[i*lineSize]), image->data, lineSize);
}
return image;
}
/*
*----------------------------------------------------------------------
* renderVGradient--
* Renders a vertical linear gradient of the specified size in the
* RImage format with a border of the specified type.
*
* Returns:
* A 24bit RImage with the gradient (no alpha channel).
*
* Side effects:
* None
*----------------------------------------------------------------------
*/
static RImage*
renderVGradient(unsigned width, unsigned height, int r0, int g0, int b0,
int rf, int gf, int bf)
{
int i, j;
long r, g, b, dr, dg, db;
RImage *image;
unsigned char *ptr;
unsigned char rr, gg, bb;
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
ptr = image->data;
r = r0<<16;
g = g0<<16;
b = b0<<16;
dr = ((rf-r0)<<16)/(int)height;
dg = ((gf-g0)<<16)/(int)height;
db = ((bf-b0)<<16)/(int)height;
for (i=0; i<height; i++) {
rr = r>>16;
gg = g>>16;
bb = b>>16;
for (j=0; j<width/8; j++) {
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
}
switch (width%8) {
case 7: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 6: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 5: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 4: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 3: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 2: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 1: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
}
r+=dr;
g+=dg;
b+=db;
}
return image;
}
/*
*----------------------------------------------------------------------
* renderDGradient--
* Renders a diagonal linear gradient of the specified size in the
* RImage format with a border of the specified type.
*
* Returns:
* A 24bit RImage with the gradient (no alpha channel).
*
* Side effects:
* None
*----------------------------------------------------------------------
*/
static RImage*
renderDGradient(unsigned width, unsigned height, int r0, int g0, int b0,
int rf, int gf, int bf)
{
RImage *image, *tmp;
int j;
float a, offset;
char *ptr;
if (width == 1)
return renderVGradient(width, height, r0, g0, b0, rf, gf, bf);
else if (height == 1)
return renderHGradient(width, height, r0, g0, b0, rf, gf, bf);
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
tmp = renderHGradient(2*width-1, 1, r0, g0, b0, rf, gf, bf);
if (!tmp) {
RReleaseImage(image);
return NULL;
}
ptr = tmp->data;
a = ((float)(width - 1))/((float)(height - 1));
width = width * 3;
/* copy the first line to the other lines with corresponding offset */
for (j=0, offset=0.0; j<width*height; j += width) {
memcpy(&(image->data[j]), &ptr[3*(int)offset], width);
offset += a;
}
RReleaseImage(tmp);
return image;
}
static RImage*
renderMHGradient(unsigned width, unsigned height, RColor **colors, int count)
{
int i, j, k;
long r, g, b, dr, dg, db;
unsigned lineSize = width*3;
RImage *image;
unsigned char *ptr;
unsigned width2;
assert(count > 2);
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
ptr = image->data;
if (count > width)
count = width;
if (count > 1)
width2 = width/(count-1);
else
width2 = width;
k = 0;
r = colors[0]->red << 16;
g = colors[0]->green << 16;
b = colors[0]->blue << 16;
/* render the first line */
for (i=1; i<count; i++) {
dr = ((int)(colors[i]->red - colors[i-1]->red) <<16)/(int)width2;
dg = ((int)(colors[i]->green - colors[i-1]->green)<<16)/(int)width2;
db = ((int)(colors[i]->blue - colors[i-1]->blue) <<16)/(int)width2;
for (j=0; j<width2; j++) {
*ptr++ = (unsigned char)(r>>16);
*ptr++ = (unsigned char)(g>>16);
*ptr++ = (unsigned char)(b>>16);
r += dr;
g += dg;
b += db;
k++;
}
r = colors[i]->red << 16;
g = colors[i]->green << 16;
b = colors[i]->blue << 16;
}
for (j=k; j<width; j++) {
*ptr++ = (unsigned char)(r>>16);
*ptr++ = (unsigned char)(g>>16);
*ptr++ = (unsigned char)(b>>16);
}
/* copy the first line to the other lines */
for (i=1; i<height; i++) {
memcpy(&(image->data[i*lineSize]), image->data, lineSize);
}
return image;
}
static RImage*
renderMVGradient(unsigned width, unsigned height, RColor **colors, int count)
{
int i, j, k;
long r, g, b, dr, dg, db;
unsigned lineSize = width*3;
RImage *image;
unsigned char *ptr, *tmp;
unsigned height2;
int x;
unsigned char rr, gg, bb;
assert(count > 2);
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
ptr = image->data;
if (count > height)
count = height;
if (count > 1)
height2 = height/(count-1);
else
height2 = height;
k = 0;
r = colors[0]->red << 16;
g = colors[0]->green << 16;
b = colors[0]->blue << 16;
for (i=1; i<count; i++) {
dr = ((int)(colors[i]->red - colors[i-1]->red) <<16)/(int)height2;
dg = ((int)(colors[i]->green - colors[i-1]->green)<<16)/(int)height2;
db = ((int)(colors[i]->blue - colors[i-1]->blue) <<16)/(int)height2;
for (j=0; j<height2; j++) {
rr = r>>16;
gg = g>>16;
bb = b>>16;
for (x=0; x<width/4; x++) {
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
}
switch (width%4) {
case 3: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
case 2: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
case 1: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
}
r += dr;
g += dg;
b += db;
k++;
}
r = colors[i]->red << 16;
g = colors[i]->green << 16;
b = colors[i]->blue << 16;
}
rr = r>>16;
gg = g>>16;
bb = b>>16;
if (k<height) {
tmp = ptr;
for (x=0; x<width/4; x++) {
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
*ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
}
switch (width%4) {
case 3: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
case 2: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
case 1: *ptr++ = rr; *ptr++ = gg; *ptr++ = bb;
default: break;
}
for (j=k+1; j<height; j++) {
memcpy(ptr, tmp, lineSize);
ptr += lineSize;
}
}
return image;
}
static RImage*
renderMDGradient(unsigned width, unsigned height, RColor **colors, int count)
{
RImage *image, *tmp;
float a, offset;
int j;
unsigned char *ptr;
assert(count > 2);
if (width == 1)
return renderMVGradient(width, height, colors, count);
else if (height == 1)
return renderMHGradient(width, height, colors, count);
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
if (count > width)
count = width;
if (count > height)
count = height;
if (count > 2)
tmp = renderMHGradient(2*width-1, 1, colors, count);
else
tmp = renderHGradient(2*width-1, 1, colors[0]->red<<8,
colors[0]->green<<8, colors[0]->blue<<8,
colors[1]->red<<8, colors[1]->green<<8,
colors[1]->blue<<8);
if (!tmp) {
RReleaseImage(image);
return NULL;
}
ptr = tmp->data;
a = ((float)(width - 1))/((float)(height - 1));
width = width * 3;
/* copy the first line to the other lines with corresponding offset */
for (j=0, offset=0; j<width*height; j += width) {
memcpy(&(image->data[j]), &ptr[3*(int)offset], width);
offset += a;
}
RReleaseImage(tmp);
return image;
}
RImage*
RRenderInterwovenGradient(unsigned width, unsigned height,
RColor colors1[2], int thickness1,
RColor colors2[2], int thickness2)
{
int i, j, k, l, ll;
long r1, g1, b1, dr1, dg1, db1;
long r2, g2, b2, dr2, dg2, db2;
RImage *image;
unsigned char *ptr;
unsigned char rr, gg, bb;
image = RCreateImage(width, height, False);
if (!image) {
return NULL;
}
ptr = image->data;
r1 = colors1[0].red<<16;
g1 = colors1[0].green<<16;
b1 = colors1[0].blue<<16;
r2 = colors2[0].red<<16;
g2 = colors2[0].green<<16;
b2 = colors2[0].blue<<16;
dr1 = ((colors1[1].red-colors1[0].red)<<16)/(int)height;
dg1 = ((colors1[1].green-colors1[0].green)<<16)/(int)height;
db1 = ((colors1[1].blue-colors1[0].blue)<<16)/(int)height;
dr2 = ((colors2[1].red-colors2[0].red)<<16)/(int)height;
dg2 = ((colors2[1].green-colors2[0].green)<<16)/(int)height;
db2 = ((colors2[1].blue-colors2[0].blue)<<16)/(int)height;
for (i=0,k=0,l=0,ll=thickness1; i<height; i++) {
if (k == 0) {
rr = r1>>16;
gg = g1>>16;
bb = b1>>16;
} else {
rr = r2>>16;
gg = g2>>16;
bb = b2>>16;
}
for (j=0; j<width/8; j++) {
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
*(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
}
switch (width%8) {
case 7: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 6: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 5: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 4: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 3: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 2: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
case 1: *(ptr++) = rr; *(ptr++) = gg; *(ptr++) = bb;
}
if (++l == ll) {
if (k == 0) {
k = 1;
ll = thickness2;
} else {
k = 0;
ll = thickness1;
}
l = 0;
}
r1+=dr1;
g1+=dg1;
b1+=db1;
r2+=dr2;
g2+=dg2;
b2+=db2;
}
return image;
}
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