darling-cocotron/AppKit/NSGradient.m

255 lines
9.1 KiB
Objective-C

/* Copyright (c) 2008 Sijmen Mulder
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
#import <AppKit/NSGradient.h>
#import <AppKit/NSBezierPath.h>
#import <AppKit/NSColor.h>
#import <AppKit/NSColorSpace.h>
#import <AppKit/NSGraphicsContext.h>
#import <AppKit/NSRaise.h>
@implementation NSGradient
static void evaluate(void *info,CGFloat const *input,CGFloat *output) {
NSGradient *self=(NSGradient *)info;
CGFloat **components=self->_components;
CGFloat *locations=self->_locations;
// Find where we are within the gradient location range - this will establish
// which color pair we are blending between
NSInteger colorIndex = 0;
for(colorIndex = 0; colorIndex < self->_numberOfColors; colorIndex++) {
if(locations[colorIndex]>=input[0]) {
// We've found the right side of the color range
break;
}
}
NSInteger startColorIndex = 0, endColorIndex = 0;
// it could be right at the limit
if (colorIndex >= self->_numberOfColors) {
startColorIndex = endColorIndex = self->_numberOfColors - 1;
} else {
endColorIndex = colorIndex;
// Start index must then be the preceding index
startColorIndex = colorIndex - 1;
if (startColorIndex < 0) {
// Make sure we don't go out of range to the left
startColorIndex = 0;
}
}
// Now here's the tricky part, we need to find out the ratio between the two colors.
// This means figuring out the distance between the two and then figuring out how far along we
// are between them
CGFloat start = locations[startColorIndex];
CGFloat length = locations[endColorIndex] - locations[startColorIndex];
CGFloat offset = input[0] - start;
CGFloat ratio = 0;
// Make sure we don't divide by 0!
if (length > 0) {
ratio = offset/length;
}
// now blend all the components using the ratio
NSInteger componentIndex;
for(componentIndex = 0; componentIndex < self->_numberOfComponents; componentIndex++){
output[componentIndex] = (components[startColorIndex][componentIndex] +
(ratio * (components[endColorIndex][componentIndex] - components[startColorIndex][componentIndex])));
}
}
-initWithStartingColor:(NSColor *)startingColor endingColor:(NSColor *)endingColor {
NSArray *colors=[NSArray arrayWithObjects:startingColor,endingColor,nil];
CGFloat locations[2]={0.0,1.0};
return [self initWithColors:colors atLocations:locations colorSpace:[NSColorSpace deviceRGBColorSpace]];
}
-initWithColors:(NSArray *)colors {
NSAssert([colors count] > 1, @"A gradient needs at least 2 colors!");
NSInteger count=[colors count];
CGFloat locations[count];
NSInteger i;
for (i = 0; i < count; i++)
locations[i]=i/(CGFloat)(count-1);
return [self initWithColors:colors atLocations:locations colorSpace:[NSColorSpace deviceRGBColorSpace]];
}
-initWithColorsAndLocations:(NSColor *)firstColor,... {
NSMutableArray *colors=[NSMutableArray array];
CGFloat locations[256]; // FIXME: seems reasonable for now
NSInteger i;
va_list arguments;
va_start(arguments,firstColor);
NSColor *color=firstColor;
for(i=0;color!=nil && i<256;i++){
[colors addObject:color];
locations[i]=va_arg(arguments,double);
color=va_arg(arguments,NSColor *);
}
va_end(arguments);
return [self initWithColors:colors atLocations:locations colorSpace:[NSColorSpace deviceRGBColorSpace]];
}
-initWithColors:(NSArray *)colors atLocations:(const CGFloat *)locations colorSpace:(NSColorSpace *)colorSpace {
_colorSpace=[[NSColorSpace deviceRGBColorSpace] retain];
_numberOfColors=[colors count];
_numberOfComponents=4;
_components=NSZoneMalloc(NULL,sizeof(CGFloat *)*_numberOfColors);
_locations=NSZoneMalloc(NULL,sizeof(CGFloat)*_numberOfColors);
NSInteger i;
for(i=0;i<_numberOfColors;i++){
NSColor *color=[colors objectAtIndex:i];
color=[color colorUsingColorSpaceName:NSDeviceRGBColorSpace];
_components[i]=NSZoneMalloc(NULL,sizeof(CGFloat)*_numberOfComponents);
[color getComponents:_components[i]];
_locations[i]=locations[i];
}
return self;
}
-(void)dealloc {
NSInteger i;
[_colorSpace release];
for(i=0;i<_numberOfColors;i++)
NSZoneFree(NULL,_components[i]);
NSZoneFree(NULL,_components);
NSZoneFree(NULL,_locations);
[super dealloc];
}
-(void)drawFromPoint:(NSPoint)startingPoint toPoint:(NSPoint)endingPoint options:(NSGradientDrawingOptions)options {
CGContextRef context=[[NSGraphicsContext currentContext] graphicsPort];
CGFunctionCallbacks callbacks = { 0, evaluate, NULL };
CGFunctionRef function = CGFunctionCreate(self, 1, NULL, _numberOfComponents, NULL, &callbacks);
CGColorSpaceRef colorSpace = [_colorSpace CGColorSpace];
CGShadingRef shading = CGShadingCreateAxial(colorSpace, startingPoint, endingPoint, function, NO, NO);
CGContextDrawShading(context,shading);
CGFunctionRelease(function);
CGShadingRelease(shading);
}
- (void)drawFromCenter:(NSPoint)startCenter radius:(CGFloat)startRadius toCenter:(NSPoint)endCenter radius:(CGFloat)endRadius options:(NSGradientDrawingOptions)options {
NSUnimplementedMethod();
}
- (void)drawInRect:(NSRect)rect angle:(CGFloat)angle
{
if (_numberOfColors < 2 || 0 == rect.size.width)
return;
CGPoint start; //start coordinate of gradient
CGPoint end; //end coordinate of gradient
//tanSize is the rectangle size for atan2 operation. It is the size of the rect in relation to the offset start point
CGPoint tanSize;
angle = (CGFloat)fmod(angle, 360);
if (angle < 90)
{
start = CGPointMake(rect.origin.x, rect.origin.y);
tanSize = CGPointMake(rect.size.width, rect.size.height);
}
else if (angle < 180)
{
start = CGPointMake(rect.origin.x + rect.size.width, rect.origin.y);
tanSize = CGPointMake(-rect.size.width, rect.size.height);
}
else if (angle < 270)
{
start = CGPointMake(rect.origin.x + rect.size.width, rect.origin.y + rect.size.height);
tanSize = CGPointMake(-rect.size.width, -rect.size.height);
}
else
{
start = CGPointMake(rect.origin.x, rect.origin.y + rect.size.height);
tanSize = CGPointMake(rect.size.width, -rect.size.height);
}
CGFloat radAngle = angle / 180 * M_PI; //Angle in radians
//The trig for this is difficult to describe without an illustration, so I'm attaching an illustration
//to Cocotron issue number 438 along with this patch
CGFloat distanceToEnd = cos(atan2(tanSize.y,tanSize.x) - radAngle) * sqrt(rect.size.width * rect.size.width + rect.size.height * rect.size.height);
end = CGPointMake(cos(radAngle) * distanceToEnd + start.x, sin(radAngle) * distanceToEnd + start.y);
CGContextRef context =[[NSGraphicsContext currentContext] graphicsPort];
CGContextSaveGState(context);
CGContextClipToRect(context, rect);
[self drawFromPoint:start toPoint:end options:NSGradientDrawsBeforeStartingLocation|NSGradientDrawsAfterEndingLocation];
CGContextRestoreGState(context);
}
-(void)drawInBezierPath:(NSBezierPath *)path angle:(CGFloat)angle {
NSRect rect=[path bounds];
[NSGraphicsContext saveGraphicsState];
[path addClip];
[self drawInRect:rect angle:angle];
[NSGraphicsContext restoreGraphicsState];
}
-(void)drawInRect:(NSRect)rect relativeCenterPosition:(NSPoint)center {
NSUnimplementedMethod();
}
-(void)drawInBezierPath:(NSBezierPath *)path relativeCenterPosition:(NSPoint)center {
NSUnimplementedMethod();
}
- (NSColorSpace *)colorSpace {
return _colorSpace;
}
- (NSInteger)numberOfColorStops {
return _numberOfColors;
}
-(void)getColor:(NSColor **)color location:(CGFloat *)location atIndex:(NSInteger)index {
if (location)
*location=_locations[index];
if (color)
*color=[NSColor colorWithCalibratedRed:_components[index][0] green:_components[index][1] blue:_components[index][2] alpha:_components[index][3]];
}
-(NSColor *)interpolatedColorAtLocation:(CGFloat)location {
CGFloat input[1]={location};
CGFloat output[4];
evaluate(self,input,output);
return [NSColor colorWithCalibratedRed:output[0] green:output[1] blue:output[2] alpha:output[3]];
}
@end