Commit c068c212 authored by Florian Müllner's avatar Florian Müllner
Browse files

gradient: Support alpha values in colors

Designers got used to RGBA support in GTK+, so the colors we pick
up from there might well have an alpha channel; update our gradient
rendering to support this - eventually we should probably port that
code to cairo ...
parent d8c47b0a
......@@ -74,14 +74,14 @@ blank_pixbuf (int width, int height)
g_return_val_if_fail (height > 0, NULL);
/* Always align rows to 32-bit boundaries */
rowstride = 4 * ((3 * width + 3) / 4);
rowstride = 4 * ((4 * width + 4) / 4);
buf = g_try_malloc (height * rowstride);
if (!buf)
return NULL;
return gdk_pixbuf_new_from_data (buf, GDK_COLORSPACE_RGB,
FALSE, 8,
TRUE, 8,
width, height, rowstride,
free_buffer, NULL);
}
......@@ -193,8 +193,8 @@ meta_gradient_create_interwoven (int width,
{
int i, j, k, l, ll;
long r1, g1, b1, dr1, dg1, db1;
long r2, g2, b2, dr2, dg2, db2;
long r1, g1, b1, a1, dr1, dg1, db1, da1;
long r2, g2, b2, a2, dr2, dg2, db2, da2;
GdkPixbuf *pixbuf;
unsigned char *ptr;
unsigned char *pixels;
......@@ -210,18 +210,22 @@ meta_gradient_create_interwoven (int width,
r1 = (long)(colors1[0].red*0xffffff);
g1 = (long)(colors1[0].green*0xffffff);
b1 = (long)(colors1[0].blue*0xffffff);
a1 = (long)(colors1[0].alpha*0xffffff);
r2 = (long)(colors2[0].red*0xffffff);
g2 = (long)(colors2[0].green*0xffffff);
b2 = (long)(colors2[0].blue*0xffffff);
a2 = (long)(colors2[0].alpha*0xffffff);
dr1 = ((colors1[1].red-colors1[0].red)*0xffffff)/(int)height;
dg1 = ((colors1[1].green-colors1[0].green)*0xffffff)/(int)height;
db1 = ((colors1[1].blue-colors1[0].blue)*0xffffff)/(int)height;
da1 = ((colors1[1].alpha-colors1[0].alpha)*0xffffff)/(int)height;
dr2 = ((colors2[1].red-colors2[0].red)*0xffffff)/(int)height;
dg2 = ((colors2[1].green-colors2[0].green)*0xffffff)/(int)height;
db2 = ((colors2[1].blue-colors2[0].blue)*0xffffff)/(int)height;
db2 = ((colors2[1].alpha-colors2[0].alpha)*0xffffff)/(int)height;
for (i=0,k=0,l=0,ll=thickness1; i<height; i++)
{
......@@ -232,17 +236,19 @@ meta_gradient_create_interwoven (int width,
ptr[0] = (unsigned char) (r1>>16);
ptr[1] = (unsigned char) (g1>>16);
ptr[2] = (unsigned char) (b1>>16);
ptr[3] = (unsigned char) (a1>>16);
}
else
{
ptr[0] = (unsigned char) (r2>>16);
ptr[1] = (unsigned char) (g2>>16);
ptr[2] = (unsigned char) (b2>>16);
ptr[3] = (unsigned char) (a2>>16);
}
for (j=1; j <= width/2; j *= 2)
memcpy (&(ptr[j*3]), ptr, j*3);
memcpy (&(ptr[j*3]), ptr, (width - j)*3);
memcpy (&(ptr[j*4]), ptr, j*4);
memcpy (&(ptr[j*4]), ptr, (width - j)*4);
if (++l == ll)
{
......@@ -261,10 +267,12 @@ meta_gradient_create_interwoven (int width,
r1+=dr1;
g1+=dg1;
b1+=db1;
a1+=da1;
r2+=dr2;
g2+=dg2;
b2+=db2;
a2+=da2;
}
return pixbuf;
......@@ -289,12 +297,12 @@ meta_gradient_create_horizontal (int width, int height,
const GdkRGBA *to)
{
int i;
long r, g, b, dr, dg, db;
long r, g, b, a, dr, dg, db, da;
GdkPixbuf *pixbuf;
unsigned char *ptr;
unsigned char *pixels;
int r0, g0, b0;
int rf, gf, bf;
int r0, g0, b0, a0;
int rf, gf, bf, af;
int rowstride;
pixbuf = blank_pixbuf (width, height);
......@@ -308,26 +316,32 @@ meta_gradient_create_horizontal (int width, int height,
r0 = (guchar) (from->red * 0xff);
g0 = (guchar) (from->green * 0xff);
b0 = (guchar) (from->blue * 0xff);
a0 = (guchar) (from->alpha * 0xff);
rf = (guchar) (to->red * 0xff);
gf = (guchar) (to->green * 0xff);
bf = (guchar) (to->blue * 0xff);
af = (guchar) (to->alpha * 0xff);
r = r0 << 16;
g = g0 << 16;
b = b0 << 16;
a = a0 << 16;
dr = ((rf-r0)<<16)/(int)width;
dg = ((gf-g0)<<16)/(int)width;
db = ((bf-b0)<<16)/(int)width;
da = ((af-a0)<<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);
*(ptr++) = (unsigned char)(a>>16);
r += dr;
g += dg;
b += db;
a += da;
}
/* copy the first line to the other lines */
......@@ -357,11 +371,11 @@ meta_gradient_create_vertical (int width, int height,
const GdkRGBA *to)
{
int i, j;
long r, g, b, dr, dg, db;
long r, g, b, a, dr, dg, db, da;
GdkPixbuf *pixbuf;
unsigned char *ptr;
int r0, g0, b0;
int rf, gf, bf;
int r0, g0, b0, a0;
int rf, gf, bf, af;
int rowstride;
unsigned char *pixels;
......@@ -375,17 +389,21 @@ meta_gradient_create_vertical (int width, int height,
r0 = (guchar) (from->red * 0xff);
g0 = (guchar) (from->green * 0xff);
b0 = (guchar) (from->blue * 0xff);
a0 = (guchar) (from->alpha * 0xff);
rf = (guchar) (to->red * 0xff);
gf = (guchar) (to->green * 0xff);
bf = (guchar) (to->blue * 0xff);
af = (guchar) (to->alpha * 0xff);
r = r0<<16;
g = g0<<16;
b = b0<<16;
a = a0<<16;
dr = ((rf-r0)<<16)/(int)height;
dg = ((gf-g0)<<16)/(int)height;
db = ((bf-b0)<<16)/(int)height;
da = ((af-a0)<<16)/(int)height;
for (i=0; i<height; i++)
{
......@@ -394,14 +412,16 @@ meta_gradient_create_vertical (int width, int height,
ptr[0] = (unsigned char)(r>>16);
ptr[1] = (unsigned char)(g>>16);
ptr[2] = (unsigned char)(b>>16);
ptr[3] = (unsigned char)(a>>16);
for (j=1; j <= width/2; j *= 2)
memcpy (&(ptr[j*3]), ptr, j*3);
memcpy (&(ptr[j*3]), ptr, (width - j)*3);
memcpy (&(ptr[j*4]), ptr, j*4);
memcpy (&(ptr[j*4]), ptr, (width - j)*4);
r+=dr;
g+=dg;
b+=db;
a+=da;
}
return pixbuf;
}
......@@ -456,12 +476,12 @@ meta_gradient_create_diagonal (int width, int height,
ptr = gdk_pixbuf_get_pixels (tmp);
a = ((float)(width - 1))/((float)(height - 1));
width = width * 3;
width = width * 4;
/* copy the first line to the other lines with corresponding offset */
for (j=0, offset=0.0; j<rowstride*height; j += rowstride)
{
memcpy (&(pixels[j]), &ptr[3*(int)offset], width);
memcpy (&(pixels[j]), &ptr[4*(int)offset], width);
offset += a;
}
......@@ -476,7 +496,7 @@ meta_gradient_create_multi_horizontal (int width, int height,
int count)
{
int i, j, k;
long r, g, b, dr, dg, db;
long r, g, b, a, dr, dg, db, da;
GdkPixbuf *pixbuf;
unsigned char *ptr;
unsigned char *pixels;
......@@ -506,6 +526,7 @@ meta_gradient_create_multi_horizontal (int width, int height,
r = (long)(colors[0].red * 0xffffff);
g = (long)(colors[0].green * 0xffffff);
b = (long)(colors[0].blue * 0xffffff);
a = (long)(colors[0].alpha * 0xffffff);
/* render the first line */
for (i=1; i<count; i++)
......@@ -513,25 +534,30 @@ meta_gradient_create_multi_horizontal (int width, int height,
dr = (int)((colors[i].red - colors[i-1].red) *0xffffff)/(int)width2;
dg = (int)((colors[i].green - colors[i-1].green)*0xffffff)/(int)width2;
db = (int)((colors[i].blue - colors[i-1].blue) *0xffffff)/(int)width2;
da = (int)((colors[i].alpha - colors[i-1].alpha) *0xffffff)/(int)width2;
for (j=0; j<width2; j++)
{
*ptr++ = (unsigned char)(r>>16);
*ptr++ = (unsigned char)(g>>16);
*ptr++ = (unsigned char)(b>>16);
*ptr++ = (unsigned char)(a>>16);
r += dr;
g += dg;
b += db;
a += da;
k++;
}
r = (long)(colors[i].red * 0xffffff);
g = (long)(colors[i].green * 0xffffff);
b = (long)(colors[i].blue * 0xffffff);
a = (long)(colors[i].alpha * 0xffffff);
}
for (j=k; j<width; j++)
{
*ptr++ = (unsigned char)(r>>16);
*ptr++ = (unsigned char)(g>>16);
*ptr++ = (unsigned char)(b>>16);
*ptr++ = (unsigned char)(a>>16);
}
/* copy the first line to the other lines */
......@@ -548,7 +574,7 @@ meta_gradient_create_multi_vertical (int width, int height,
int count)
{
int i, j, k;
long r, g, b, dr, dg, db;
long r, g, b, a, dr, dg, db, da;
GdkPixbuf *pixbuf;
unsigned char *ptr, *tmp, *pixels;
int height2;
......@@ -578,33 +604,38 @@ meta_gradient_create_multi_vertical (int width, int height,
r = (long)(colors[0].red * 0xffffff);
g = (long)(colors[0].green * 0xffffff);
b = (long)(colors[0].blue * 0xffffff);
a = (long)(colors[0].alpha * 0xffffff);
for (i=1; i<count; i++)
{
dr = (int)((colors[i].red - colors[i-1].red) *0xffffff)/(int)height2;
dg = (int)((colors[i].green - colors[i-1].green)*0xffffff)/(int)height2;
db = (int)((colors[i].blue - colors[i-1].blue) *0xffffff)/(int)height2;
da = (int)((colors[i].alpha - colors[i-1].alpha) *0xffffff)/(int)height2;
for (j=0; j<height2; j++)
{
ptr[0] = (unsigned char)(r>>16);
ptr[1] = (unsigned char)(g>>16);
ptr[2] = (unsigned char)(b>>16);
ptr[3] = (unsigned char)(a>>16);
for (x=1; x <= width/2; x *= 2)
memcpy (&(ptr[x*3]), ptr, x*3);
memcpy (&(ptr[x*3]), ptr, (width - x)*3);
memcpy (&(ptr[x*4]), ptr, x*4);
memcpy (&(ptr[x*4]), ptr, (width - x)*4);
ptr += rowstride;
r += dr;
g += dg;
b += db;
a += da;
k++;
}
r = (long)(colors[i].red * 0xffffff);
g = (long)(colors[i].green * 0xffffff);
b = (long)(colors[i].blue * 0xffffff);
a = (long)(colors[i].alpha * 0xffffff);
}
if (k<height)
......@@ -614,10 +645,11 @@ meta_gradient_create_multi_vertical (int width, int height,
ptr[0] = (unsigned char) (r>>16);
ptr[1] = (unsigned char) (g>>16);
ptr[2] = (unsigned char) (b>>16);
ptr[3] = (unsigned char) (a>>16);
for (x=1; x <= width/2; x *= 2)
memcpy (&(ptr[x*3]), ptr, x*3);
memcpy (&(ptr[x*3]), ptr, (width - x)*3);
memcpy (&(ptr[x*4]), ptr, x*4);
memcpy (&(ptr[x*4]), ptr, (width - x)*4);
ptr += rowstride;
......
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