#include <gtk/gtk.h>

#include "sp-color-scales.h"

#include "preferences.h"

#define SLIDER_WIDTH 96

#define SLIDER_HEIGHT 8

#define ARROW_SIZE 7

enum {

GRABBED,

DRAGGED,

RELEASED,

CHANGED,

LAST_SIGNAL

};

static void sp_color_slider_class_init (SPColorSliderClass *klass);

static void sp_color_slider_init (SPColorSlider *slider);

static void sp_color_slider_dispose(GObject *object);

static void sp_color_slider_realize (GtkWidget *widget);

static void sp_color_slider_size_request (GtkWidget *widget, GtkRequisition *requisition);

#if GTK_CHECK_VERSION(3,0,0)

static void sp_color_slider_get_preferred_width(GtkWidget *widget,

gint *minimal_width,

gint *natural_width);

static void sp_color_slider_get_preferred_height(GtkWidget *widget,

gint *minimal_height,

gint *natural_height);

#else

static gboolean sp_color_slider_expose(GtkWidget *widget, GdkEventExpose *event);

#endif

static void sp_color_slider_size_allocate (GtkWidget *widget, GtkAllocation *allocation);

static gboolean sp_color_slider_draw(GtkWidget *widget, cairo_t *cr);

static gint sp_color_slider_button_press (GtkWidget *widget, GdkEventButton *event);

static gint sp_color_slider_button_release (GtkWidget *widget, GdkEventButton *event);

static gint sp_color_slider_motion_notify (GtkWidget *widget, GdkEventMotion *event);

static void sp_color_slider_adjustment_changed (GtkAdjustment *adjustment, SPColorSlider *slider);

static void sp_color_slider_adjustment_value_changed (GtkAdjustment *adjustment, SPColorSlider *slider);

static const guchar *sp_color_slider_render_gradient (gint x0, gint y0, gint width, gint height,

gint c[], gint dc[], guint b0, guint b1, guint mask);

static const guchar *sp_color_slider_render_map (gint x0, gint y0, gint width, gint height,

guchar *map, gint start, gint step, guint b0, guint b1, guint mask);

static GtkWidgetClass *parent_class;

static guint slider_signals[LAST_SIGNAL] = {0};

sp_color_slider_get_type (void)

{

static GType type = 0;

if (!type) {

GTypeInfo info = {

sizeof (SPColorSliderClass),

NULL, NULL,

(GClassInitFunc) sp_color_slider_class_init,

NULL, NULL,

sizeof (SPColorSlider),

0,

(GInstanceInitFunc) sp_color_slider_init,

NULL

};

type = g_type_register_static (GTK_TYPE_WIDGET, "SPColorSlider", &info, (GTypeFlags)0);

}

return type;

}

static void sp_color_slider_class_init(SPColorSliderClass *klass)

{

GObjectClass *object_class = G_OBJECT_CLASS(klass);

GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);

parent_class = GTK_WIDGET_CLASS(g_type_class_peek_parent(klass));

slider_signals[GRABBED] = g_signal_new ("grabbed",

G_TYPE_FROM_CLASS(object_class),

(GSignalFlags)(G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE),

G_STRUCT_OFFSET (SPColorSliderClass, grabbed),

NULL, NULL,

g_cclosure_marshal_VOID__VOID,

G_TYPE_NONE, 0);

slider_signals[DRAGGED] = g_signal_new ("dragged",

G_TYPE_FROM_CLASS(object_class),

(GSignalFlags)(G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE),

G_STRUCT_OFFSET (SPColorSliderClass, dragged),

NULL, NULL,

g_cclosure_marshal_VOID__VOID,

G_TYPE_NONE, 0);

slider_signals[RELEASED] = g_signal_new ("released",

G_TYPE_FROM_CLASS(object_class),

(GSignalFlags)(G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE),

G_STRUCT_OFFSET (SPColorSliderClass, released),

NULL, NULL,

g_cclosure_marshal_VOID__VOID,

G_TYPE_NONE, 0);

slider_signals[CHANGED] = g_signal_new ("changed",

G_TYPE_FROM_CLASS(object_class),

(GSignalFlags)(G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE),

G_STRUCT_OFFSET (SPColorSliderClass, changed),

NULL, NULL,

g_cclosure_marshal_VOID__VOID,

G_TYPE_NONE, 0);

object_class->dispose = sp_color_slider_dispose;

widget_class->realize = sp_color_slider_realize;

#if GTK_CHECK_VERSION(3,0,0)

widget_class->get_preferred_width = sp_color_slider_get_preferred_width;

widget_class->get_preferred_height = sp_color_slider_get_preferred_height;

widget_class->draw = sp_color_slider_draw;

#else

widget_class->size_request = sp_color_slider_size_request;

widget_class->expose_event = sp_color_slider_expose;

#endif

widget_class->size_allocate = sp_color_slider_size_allocate;

widget_class->button_press_event = sp_color_slider_button_press;

widget_class->button_release_event = sp_color_slider_button_release;

widget_class->motion_notify_event = sp_color_slider_motion_notify;

}

static void

sp_color_slider_init (SPColorSlider *slider)

{

/* We are widget with window */

gtk_widget_set_has_window (GTK_WIDGET(slider), TRUE);

slider->dragging = FALSE;

slider->adjustment = NULL;

slider->value = 0.0;

slider->c0[0] = 0x00;

slider->c0[1] = 0x00;

slider->c0[2] = 0x00;

slider->c0[3] = 0xff;

slider->cm[0] = 0xff;

slider->cm[1] = 0x00;

slider->cm[2] = 0x00;

slider->cm[3] = 0xff;

slider->c1[0] = 0xff;

slider->c1[1] = 0xff;

slider->c1[2] = 0xff;

slider->c1[3] = 0xff;

slider->b0 = 0x5f;

slider->b1 = 0xa0;

slider->bmask = 0x08;

slider->map = NULL;

}

static void sp_color_slider_dispose(GObject *object)

{

SPColorSlider *slider = SP_COLOR_SLIDER (object);

if (slider->adjustment) {

g_signal_handlers_disconnect_matched (G_OBJECT (slider->adjustment), G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, slider);

g_object_unref (slider->adjustment);

slider->adjustment = NULL;

}

if ((G_OBJECT_CLASS(parent_class))->dispose)

(* (G_OBJECT_CLASS(parent_class))->dispose) (object);

}

static void

sp_color_slider_realize (GtkWidget *widget)

{

GdkWindowAttr attributes;

gint attributes_mask;

GtkAllocation allocation;

gtk_widget_get_allocation(widget, &allocation);

gtk_widget_set_realized (widget, TRUE);

attributes.window_type = GDK_WINDOW_CHILD;

attributes.x = allocation.x;

attributes.y = allocation.y;

attributes.width = allocation.width;

attributes.height = allocation.height;

attributes.wclass = GDK_INPUT_OUTPUT;

attributes.visual = gdk_screen_get_system_visual(gdk_screen_get_default());

#if !GTK_CHECK_VERSION(3,0,0)

attributes.colormap = gdk_screen_get_system_colormap(gdk_screen_get_default());

#endif

attributes.event_mask = gtk_widget_get_events (widget);

attributes.event_mask |= (GDK_EXPOSURE_MASK |

GDK_BUTTON_PRESS_MASK |

GDK_BUTTON_RELEASE_MASK |

GDK_POINTER_MOTION_MASK |

GDK_ENTER_NOTIFY_MASK |

GDK_LEAVE_NOTIFY_MASK);

#if GTK_CHECK_VERSION(3,0,0)

attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;

#else

attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;

#endif

gtk_widget_set_window(widget,

gdk_window_new(gtk_widget_get_parent_window(widget),

&attributes, attributes_mask));

gdk_window_set_user_data(gtk_widget_get_window(widget), widget);

#if !GTK_CHECK_VERSION(3,0,0)

// This doesn't do anything in GTK+ 3

gtk_widget_set_style(widget,

gtk_style_attach(gtk_widget_get_style(widget),

gtk_widget_get_window(widget)));

#endif

}

static void

sp_color_slider_size_request (GtkWidget *widget, GtkRequisition *requisition)

{

GtkStyle *style = gtk_widget_get_style(widget);

requisition->width = SLIDER_WIDTH + style->xthickness * 2;

requisition->height = SLIDER_HEIGHT + style->ythickness * 2;

}

#if GTK_CHECK_VERSION(3,0,0)

static void sp_color_slider_get_preferred_width(GtkWidget *widget, gint *minimal_width, gint *natural_width)

{

GtkRequisition requisition;

sp_color_slider_size_request(widget, &requisition);

*minimal_width = *natural_width = requisition.width;

}

static void sp_color_slider_get_preferred_height(GtkWidget *widget, gint *minimal_height, gint *natural_height)

{

GtkRequisition requisition;

sp_color_slider_size_request(widget, &requisition);

*minimal_height = *natural_height = requisition.height;

}

#endif

static void

sp_color_slider_size_allocate (GtkWidget *widget, GtkAllocation *allocation)

{

gtk_widget_set_allocation(widget, allocation);

if (gtk_widget_get_realized (widget)) {

/* Resize GdkWindow */

gdk_window_move_resize(gtk_widget_get_window(widget),

allocation->x, allocation->y,

allocation->width, allocation->height);

}

}

#if !GTK_CHECK_VERSION(3,0,0)

static gboolean sp_color_slider_expose(GtkWidget *widget, GdkEventExpose * /*event*/)

{

gboolean result = FALSE;

if (gtk_widget_is_drawable(widget)) {

GdkWindow *window = gtk_widget_get_window(widget);

cairo_t *cr = gdk_cairo_create(window);

result = sp_color_slider_draw(widget, cr);

cairo_destroy(cr);

}

return result;

}

#endif

static gint

sp_color_slider_button_press (GtkWidget *widget, GdkEventButton *event)

{

SPColorSlider *slider;

slider = SP_COLOR_SLIDER (widget);

if (event->button == 1) {

GtkAllocation allocation;

gtk_widget_get_allocation(widget, &allocation);

gint cx, cw;

cx = gtk_widget_get_style(widget)->xthickness;

cw = allocation.width - 2 * cx;

g_signal_emit (G_OBJECT (slider), slider_signals[GRABBED], 0);

slider->dragging = TRUE;

slider->oldvalue = slider->value;

ColorScales::setScaled( slider->adjustment, CLAMP ((gfloat) (event->x - cx) / cw, 0.0, 1.0) );

g_signal_emit (G_OBJECT (slider), slider_signals[DRAGGED], 0);

#if GTK_CHECK_VERSION(3,0,0)

gdk_device_grab(gdk_event_get_device(reinterpret_cast<GdkEvent *>(event)),

gtk_widget_get_window(widget),

GDK_OWNERSHIP_NONE,

FALSE,

static_cast<GdkEventMask>(GDK_POINTER_MOTION_MASK | GDK_BUTTON_RELEASE_MASK),

NULL,

event->time);

#else

gdk_pointer_grab(gtk_widget_get_window(widget), FALSE,

static_cast<GdkEventMask>(GDK_POINTER_MOTION_MASK | GDK_BUTTON_RELEASE_MASK),

NULL, NULL, event->time);

#endif

}

return FALSE;

}

static gint

sp_color_slider_button_release (GtkWidget *widget, GdkEventButton *event)

{

SPColorSlider *slider;

slider = SP_COLOR_SLIDER (widget);

if (event->button == 1) {

#if GTK_CHECK_VERSION(3,0,0)

gdk_device_ungrab(gdk_event_get_device(reinterpret_cast<GdkEvent *>(event)),

gdk_event_get_time(reinterpret_cast<GdkEvent *>(event)));

#else

gdk_pointer_ungrab (event->time);

#endif

slider->dragging = FALSE;

g_signal_emit (G_OBJECT (slider), slider_signals[RELEASED], 0);

if (slider->value != slider->oldvalue) g_signal_emit (G_OBJECT (slider), slider_signals[CHANGED], 0);

}

return FALSE;

}

static gint

sp_color_slider_motion_notify (GtkWidget *widget, GdkEventMotion *event)

{

SPColorSlider *slider;

slider = SP_COLOR_SLIDER (widget);

if (slider->dragging) {

gint cx, cw;

GtkAllocation allocation;

gtk_widget_get_allocation(widget, &allocation);

cx = gtk_widget_get_style(widget)->xthickness;

cw = allocation.width - 2 * cx;

ColorScales::setScaled( slider->adjustment, CLAMP ((gfloat) (event->x - cx) / cw, 0.0, 1.0) );

g_signal_emit (G_OBJECT (slider), slider_signals[DRAGGED], 0);

}

return FALSE;

}

GtkWidget *sp_color_slider_new(GtkAdjustment *adjustment)

{

SPColorSlider *slider = SP_COLOR_SLIDER(g_object_new(SP_TYPE_COLOR_SLIDER, NULL));

sp_color_slider_set_adjustment (slider, adjustment);

return GTK_WIDGET (slider);

}

void sp_color_slider_set_adjustment(SPColorSlider *slider, GtkAdjustment *adjustment)

{

g_return_if_fail (slider != NULL);

g_return_if_fail (SP_IS_COLOR_SLIDER (slider));

if (!adjustment) {

adjustment = GTK_ADJUSTMENT(gtk_adjustment_new(0.0, 0.0, 1.0, 0.01, 0.0, 0.0));

} else {

gtk_adjustment_set_page_increment(adjustment, 0.0);

gtk_adjustment_set_page_size(adjustment, 0.0);

}

if (slider->adjustment != adjustment) {

if (slider->adjustment) {

g_signal_handlers_disconnect_matched (G_OBJECT (slider->adjustment), G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, slider);

g_object_unref (slider->adjustment);

}

slider->adjustment = adjustment;

g_object_ref (adjustment);

g_object_ref_sink (adjustment);

g_signal_connect (G_OBJECT (adjustment), "changed",

G_CALLBACK (sp_color_slider_adjustment_changed), slider);

g_signal_connect (G_OBJECT (adjustment), "value_changed",

G_CALLBACK (sp_color_slider_adjustment_value_changed), slider);

slider->value = ColorScales::getScaled( adjustment );

sp_color_slider_adjustment_changed (adjustment, slider);

}

}

sp_color_slider_set_colors (SPColorSlider *slider, guint32 start, guint32 mid, guint32 end)

{

g_return_if_fail (slider != NULL);

g_return_if_fail (SP_IS_COLOR_SLIDER (slider));

// Remove any map, if set

slider->map = 0;

slider->c0[0] = start >> 24;

slider->c0[1] = (start >> 16) & 0xff;

slider->c0[2] = (start >> 8) & 0xff;

slider->c0[3] = start & 0xff;

slider->cm[0] = mid >> 24;

slider->cm[1] = (mid >> 16) & 0xff;

slider->cm[2] = (mid >> 8) & 0xff;

slider->cm[3] = mid & 0xff;

slider->c1[0] = end >> 24;

slider->c1[1] = (end >> 16) & 0xff;

slider->c1[2] = (end >> 8) & 0xff;

slider->c1[3] = end & 0xff;

gtk_widget_queue_draw (GTK_WIDGET (slider));

}

sp_color_slider_set_map (SPColorSlider *slider, const guchar *map)

{

g_return_if_fail (slider != NULL);

g_return_if_fail (SP_IS_COLOR_SLIDER (slider));

slider->map = const_cast<guchar *>(map);

gtk_widget_queue_draw (GTK_WIDGET (slider));

}

sp_color_slider_set_background (SPColorSlider *slider, guint dark, guint light, guint size)

{

g_return_if_fail (slider != NULL);

g_return_if_fail (SP_IS_COLOR_SLIDER (slider));

slider->b0 = dark;

slider->b1 = light;

slider->bmask = size;

gtk_widget_queue_draw (GTK_WIDGET (slider));

}

static void

sp_color_slider_adjustment_changed (GtkAdjustment */*adjustment*/, SPColorSlider *slider)

{

gtk_widget_queue_draw (GTK_WIDGET (slider));

}

static void

sp_color_slider_adjustment_value_changed (GtkAdjustment *adjustment, SPColorSlider *slider)

{

GtkWidget *widget;

widget = GTK_WIDGET (slider);

if (slider->value != ColorScales::getScaled( adjustment )) {

gint cx, cy, cw, ch;

GtkStyle *style = gtk_widget_get_style(widget);

GtkAllocation allocation;

gtk_widget_get_allocation(widget, &allocation);

cx = style->xthickness;

cy = style->ythickness;

cw = allocation.width - 2 * cx;

ch = allocation.height - 2 * cy;

if ((gint) (ColorScales::getScaled( adjustment ) * cw) != (gint) (slider->value * cw)) {

gint ax, ay;

gfloat value;

value = slider->value;

slider->value = ColorScales::getScaled( adjustment );

ax = (int)(cx + value * cw - ARROW_SIZE / 2 - 2);

ay = cy;

gtk_widget_queue_draw_area (widget, ax, ay, ARROW_SIZE + 4, ch);

ax = (int)(cx + slider->value * cw - ARROW_SIZE / 2 - 2);

ay = cy;

gtk_widget_queue_draw_area (widget, ax, ay, ARROW_SIZE + 4, ch);

} else {

slider->value = ColorScales::getScaled( adjustment );

}

}

}

static gboolean sp_color_slider_draw(GtkWidget *widget, cairo_t *cr)

{

SPColorSlider *slider = SP_COLOR_SLIDER(widget);

gboolean colorsOnTop = Inkscape::Preferences::get()->getBool("/options/workarounds/colorsontop", false);

GtkAllocation allocation;

gtk_widget_get_allocation(widget, &allocation);

#if GTK_CHECK_VERSION(3,0,0)

GtkStyleContext *context = gtk_widget_get_style_context(widget);

#else

GdkWindow *window = gtk_widget_get_window(widget);

GtkStyle *style = gtk_widget_get_style(widget);

#endif

// Draw shadow

if (colorsOnTop) {

#if GTK_CHECK_VERSION(3,0,0)

gtk_render_frame(context,

cr,

0, 0,

allocation.width, allocation.height);

#else

gtk_paint_shadow( style, window,

gtk_widget_get_state(widget), GTK_SHADOW_IN,

NULL, widget, "colorslider",

0, 0,

allocation.width, allocation.height);

#endif

}

/* Paintable part of color gradient area */

GdkRectangle carea;

#if GTK_CHECK_VERSION(3,0,0)

GtkBorder padding;

gtk_style_context_get_padding(context,

gtk_widget_get_state_flags(widget),

&padding);

carea.x = padding.left;

carea.y = padding.top;

#else

carea.x = style->xthickness;

carea.y = style->ythickness;

#endif

carea.width = allocation.width - 2 * carea.x;

carea.height = allocation.height - 2 * carea.y;

if (slider->map) {

/* Render map pixelstore */

gint d = (1024 << 16) / carea.width;

gint s = 0;

const guchar *b = sp_color_slider_render_map(0, 0, carea.width, carea.height,

slider->map, s, d,

slider->b0, slider->b1, slider->bmask);

if (b != NULL && carea.width > 0) {

GdkPixbuf *pb = gdk_pixbuf_new_from_data (b, GDK_COLORSPACE_RGB,

0, 8, carea.width, carea.height, carea.width * 3, NULL, NULL);

gdk_cairo_set_source_pixbuf(cr, pb, carea.x, carea.y);

cairo_paint(cr);

g_object_unref(pb);

}

} else {

gint c[4], dc[4];

/* Render gradient */

// part 1: from c0 to cm

if (carea.width > 0) {

for (gint i = 0; i < 4; i++) {

c[i] = slider->c0[i] << 16;

dc[i] = ((slider->cm[i] << 16) - c[i]) / (carea.width/2);

}

guint wi = carea.width/2;

const guchar *b = sp_color_slider_render_gradient(0, 0, wi, carea.height,

c, dc, slider->b0, slider->b1, slider->bmask);

/* Draw pixelstore 1 */

if (b != NULL && wi > 0) {

GdkPixbuf *pb = gdk_pixbuf_new_from_data (b, GDK_COLORSPACE_RGB,

0, 8, wi, carea.height, wi * 3, NULL, NULL);

gdk_cairo_set_source_pixbuf(cr, pb, carea.x, carea.y);

cairo_paint(cr);

g_object_unref(pb);

}

}

// part 2: from cm to c1

if (carea.width > 0) {

for (gint i = 0; i < 4; i++) {

c[i] = slider->cm[i] << 16;

dc[i] = ((slider->c1[i] << 16) - c[i]) / (carea.width/2);

}

guint wi = carea.width/2;

const guchar *b = sp_color_slider_render_gradient(carea.width/2, 0, wi, carea.height,

c, dc,

slider->b0, slider->b1, slider->bmask);

/* Draw pixelstore 2 */

if (b != NULL && wi > 0) {

GdkPixbuf *pb = gdk_pixbuf_new_from_data (b, GDK_COLORSPACE_RGB,

0, 8, wi, carea.height, wi * 3, NULL, NULL);

gdk_cairo_set_source_pixbuf(cr, pb, carea.width/2 + carea.x, carea.y);

cairo_paint(cr);

g_object_unref(pb);

}

}

}

/* Draw shadow */

if (!colorsOnTop) {

#if GTK_CHECK_VERSION(3,0,0)

gtk_render_frame(context,

cr,

0, 0,

allocation.width, allocation.height);

#else

gtk_paint_shadow( style, window,

gtk_widget_get_state(widget), GTK_SHADOW_IN,

NULL, widget, "colorslider",

0, 0,

allocation.width, allocation.height);

#endif

}

/* Draw arrow */

gint x = (int)(slider->value * (carea.width - 1) - ARROW_SIZE / 2 + carea.x);

gint y1 = carea.y;

gint y2 = carea.y + carea.height - 1;

cairo_set_line_width(cr, 1.0);

// Define top arrow

cairo_move_to(cr, x - 0.5, y1 + 0.5);

cairo_line_to(cr, x + ARROW_SIZE - 0.5, y1 + 0.5);

cairo_line_to(cr, x + (ARROW_SIZE-1)/2.0, y1 + ARROW_SIZE/2.0 + 0.5);

cairo_line_to(cr, x - 0.5, y1 + 0.5);

// Define bottom arrow

cairo_move_to(cr, x - 0.5, y2 + 0.5);

cairo_line_to(cr, x + ARROW_SIZE - 0.5, y2 + 0.5);

cairo_line_to(cr, x + (ARROW_SIZE-1)/2.0, y2 - ARROW_SIZE/2.0 + 0.5);

cairo_line_to(cr, x - 0.5, y2 + 0.5);

// Render both arrows

cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);

cairo_stroke_preserve(cr);

cairo_set_source_rgb(cr, 0.0, 0.0, 0.0);

cairo_fill(cr);

return FALSE;

}

static const guchar *

sp_color_slider_render_gradient (gint x0, gint y0, gint width, gint height,

gint c[], gint dc[], guint b0, guint b1, guint mask)

{

static guchar *buf = NULL;

static gint bs = 0;

guchar *dp;

gint x, y;

guint r, g, b, a;

if (buf && (bs < width * height)) {

g_free (buf);

buf = NULL;

}

if (!buf) {

buf = g_new (guchar, width * height * 3);

bs = width * height;

}

dp = buf;

r = c[0];

g = c[1];

b = c[2];

a = c[3];

for (x = x0; x < x0 + width; x++) {

gint cr, cg, cb, ca;

guchar *d;

cr = r >> 16;

cg = g >> 16;

cb = b >> 16;

ca = a >> 16;

d = dp;

for (y = y0; y < y0 + height; y++) {

guint bg, fc;

/* Background value */

bg = ((x & mask) ^ (y & mask)) ? b0 : b1;

fc = (cr - bg) * ca;

d[0] = bg + ((fc + (fc >> 8) + 0x80) >> 8);

fc = (cg - bg) * ca;

d[1] = bg + ((fc + (fc >> 8) + 0x80) >> 8);

fc = (cb - bg) * ca;

d[2] = bg + ((fc + (fc >> 8) + 0x80) >> 8);

d += 3 * width;

}

r += dc[0];

g += dc[1];

b += dc[2];

a += dc[3];

dp += 3;

}

return buf;

}

static const guchar *

sp_color_slider_render_map (gint x0, gint y0, gint width, gint height,

guchar *map, gint start, gint step, guint b0, guint b1, guint mask)

{

static guchar *buf = NULL;

static gint bs = 0;

guchar *dp, *sp;

gint x, y;

if (buf && (bs < width * height)) {

g_free (buf);

buf = NULL;

}

if (!buf) {

buf = g_new (guchar, width * height * 3);

bs = width * height;

}

dp = buf;

for (x = x0; x < x0 + width; x++) {

gint cr, cg, cb, ca;

guchar *d;

sp = map + 4 * (start >> 16);

cr = *sp++;

cg = *sp++;

cb = *sp++;

ca = *sp++;

d = dp;

for (y = y0; y < y0 + height; y++) {

guint bg, fc;

/* Background value */

bg = ((x & mask) ^ (y & mask)) ? b0 : b1;

fc = (cr - bg) * ca;

d[0] = bg + ((fc + (fc >> 8) + 0x80) >> 8);

fc = (cg - bg) * ca;

d[1] = bg + ((fc + (fc >> 8) + 0x80) >> 8);

fc = (cb - bg) * ca;

d[2] = bg + ((fc + (fc >> 8) + 0x80) >> 8);

d += 3 * width;

}

dp += 3;

start += step;

}

return buf;

}