awesome/color.c

226 lines
6.9 KiB
C

/*
* color.c - color functions
*
* Copyright © 2008-2009 Julien Danjou <julien@danjou.info>
* Copyright © 2009 Uli Schlachter <psychon@znc.in>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include "color.h"
#include "globalconf.h"
#include <ctype.h>
/* 0xFFFF / 0xFF == 0x101 (257) */
#define RGB_8TO16(i) (((i) & 0xff) * 0x101)
#define RGB_16TO8(i) (((i) & 0xffff) / 0x101)
/** Parse an hexadecimal color string to its component.
* \param colstr The color string.
* \param len The color string length.
* \param red A pointer to the red color to fill.
* \param green A pointer to the green color to fill.
* \param blue A pointer to the blue color to fill.
* \return True if everything alright.
*/
static bool
color_parse(const char *colstr, ssize_t len,
uint8_t *red, uint8_t *green, uint8_t *blue, uint8_t *alpha)
{
unsigned long colnum;
char *p;
*alpha = 0xff;
colnum = strtoul(colstr + 1, &p, 16);
if(len == 9 && (p - colstr) == 9)
{
*alpha = colnum & 0xff;
colnum >>= 8;
len -= 2;
p -= 2;
}
if(len != 7 || colstr[0] != '#' || (p - colstr) != 7)
{
warn("awesome: error, invalid color '%s'", colstr);
return false;
}
*red = (colnum >> 16) & 0xff;
*green = (colnum >> 8) & 0xff;
*blue = colnum & 0xff;
return true;
}
/** Given a color component value in the range from 0x00 to 0xff and a mask that
* specifies where the component is, move the component into place. For example,
* component=0x12 and mask=0xff00 return 0x1200. Note that the mask can have a
* different width, for example component=0x12 and mask=0xf00 return 0x100.
* \param component The intensity of a color component.
* \param mask A mask containing a consecutive number of bits set to 1 defining
* where the component is.
* \return A pixel value containing the giving component in the given component.
*/
static uint32_t
apply_mask(uint8_t component, uint32_t mask)
{
unsigned int shift = 0;
unsigned int width = 0;
// Shift the mask right until the first set bit appears
while (mask != 0 && (mask & 0x1) == 0) {
shift++;
mask >>= 1;
}
// Shift the mask right until we saw all set bits
while ((mask & 0x1) == 1) {
width++;
mask >>= 1;
}
// The mask consists of [width] set bits followed by [shift] unset bits.
// Modify the component accordingly.
uint32_t result = component;
// Scale the result up to the desired width
if (width < 8)
result >>= (8 - width);
if (width > 8)
result <<= (width - 8);
return result << shift;
}
/** Send a request to initialize a X color.
* \param color color_t struct to store color into.
* \param colstr Color specification.
* \param len The length of colstr (which still MUST be NULL terminated).
* \param visual The visual for which the color is to be allocated.
* \return request information.
*/
color_init_request_t
color_init_unchecked(color_t *color, const char *colstr, ssize_t len, xcb_visualtype_t *visual)
{
color_init_request_t req;
uint8_t red, green, blue, alpha;
p_clear(&req, 1);
if(!len)
{
req.has_error = true;
return req;
}
req.color = color;
/* The color is given in RGB value */
if(!color_parse(colstr, len, &red, &green, &blue, &alpha))
{
warn("awesome: error, invalid color '%s'", colstr);
req.has_error = true;
return req;
}
req.colstr = colstr;
req.has_error = false;
if (visual->_class == XCB_VISUAL_CLASS_TRUE_COLOR || visual->_class == XCB_VISUAL_CLASS_DIRECT_COLOR) {
uint32_t pixel = 0;
pixel |= apply_mask(red, visual->red_mask);
pixel |= apply_mask(blue, visual->blue_mask);
pixel |= apply_mask(green, visual->green_mask);
if (draw_visual_depth(globalconf.screen, visual->visual_id) == 32) {
/* This is not actually in the X11 protocol, but we assume that this
* is an ARGB visual and everything unset in some mask is alpha.
*/
pixel |= apply_mask(alpha, ~(visual->red_mask | visual->blue_mask | visual->green_mask));
}
req.color->pixel = pixel;
req.color->red = RGB_8TO16(red);
req.color->green = RGB_8TO16(green);
req.color->blue = RGB_8TO16(blue);
req.color->alpha = RGB_8TO16(alpha);
req.color->initialized = true;
return req;
}
req.cookie_hexa = xcb_alloc_color_unchecked(globalconf.connection,
globalconf.screen_cmap,
RGB_8TO16(red),
RGB_8TO16(green),
RGB_8TO16(blue));
return req;
}
/** Initialize a X color.
* \param req color_init request.
* \return True if color allocation was successful.
*/
bool
color_init_reply(color_init_request_t req)
{
if(req.has_error)
return false;
if(req.color->initialized)
return true;
xcb_alloc_color_reply_t *hexa_color;
if((hexa_color = xcb_alloc_color_reply(globalconf.connection,
req.cookie_hexa, NULL)))
{
req.color->pixel = hexa_color->pixel;
req.color->red = hexa_color->red;
req.color->green = hexa_color->green;
req.color->blue = hexa_color->blue;
req.color->alpha = 0xffff;
req.color->initialized = true;
p_delete(&hexa_color);
return true;
}
warn("awesome: error, cannot allocate color '%s'", req.colstr);
return false;
}
/** Push a color as a string onto the stack
* \param L The Lua VM state.
* \param c The color to push.
* \return The number of elements pushed on stack.
*/
int
luaA_pushcolor(lua_State *L, const color_t c)
{
uint8_t r = RGB_16TO8(c.red);
uint8_t g = RGB_16TO8(c.green);
uint8_t b = RGB_16TO8(c.blue);
uint8_t a = RGB_16TO8(c.alpha);
char s[1 + 4*2 + 1];
int len;
if (a >= 0xff)
len = snprintf(s, sizeof(s), "#%02x%02x%02x", r, g, b);
else
len = snprintf(s, sizeof(s), "#%02x%02x%02x%02x", r, g, b, a);
lua_pushlstring(L, s, len);
return 1;
}
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