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Either solved, dropped, or relegated to LONGTERM many of drawtext.m's TODOs.

This commit is contained in:
Pietro Gagliardi 2016-05-28 23:37:07 -04:00
parent 58d59f4370
commit 84d3df031f
2 changed files with 28 additions and 30 deletions
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48
darwin/drawtext.m
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@ -4,8 +4,7 @@
// TODO // TODO
#define complain(...) implbug(__VA_ARGS__) #define complain(...) implbug(__VA_ARGS__)
// TODO for all relevant routines, make sure we are freeing memory correctly // TODO double-check that we are properly handling allocation failures (or just toll free bridge from cocoa)
// TODO make sure allocation failures throw exceptions?
struct uiDrawFontFamilies { struct uiDrawFontFamilies {
CFArrayRef fonts; CFArrayRef fonts;
}; };
@ -15,7 +14,6 @@ uiDrawFontFamilies *uiDrawListFontFamilies(void)
uiDrawFontFamilies *ff; uiDrawFontFamilies *ff;
ff = uiNew(uiDrawFontFamilies); ff = uiNew(uiDrawFontFamilies);
// TODO is there a way to get an error reason?
ff->fonts = CTFontManagerCopyAvailableFontFamilyNames(); ff->fonts = CTFontManagerCopyAvailableFontFamilyNames();
if (ff->fonts == NULL) if (ff->fonts == NULL)
implbug("error getting available font names (no reason specified) (TODO)"); implbug("error getting available font names (no reason specified) (TODO)");
@ -33,7 +31,7 @@ char *uiDrawFontFamiliesFamily(uiDrawFontFamilies *ff, uintmax_t n)
char *family; char *family;
familystr = (CFStringRef) CFArrayGetValueAtIndex(ff->fonts, n); familystr = (CFStringRef) CFArrayGetValueAtIndex(ff->fonts, n);
// TODO create a uiDarwinCFStringToText()? // toll-free bridge
family = uiDarwinNSStringToText((NSString *) familystr); family = uiDarwinNSStringToText((NSString *) familystr);
// Get Rule means we do not free familystr // Get Rule means we do not free familystr
return family; return family;
@ -155,12 +153,11 @@ static void addFontSmallCapsAttr(CFMutableDictionaryRef attr)
#define ourNSFontWeightBlack 0.620000 #define ourNSFontWeightBlack 0.620000
static const CGFloat ctWeights[] = { static const CGFloat ctWeights[] = {
// yeah these two have their names swapped; blame Pango // yeah these two have their names swapped; blame Pango
// TODO note that these names do not necessarily line up with their OS names
[uiDrawTextWeightThin] = ourNSFontWeightUltraLight, [uiDrawTextWeightThin] = ourNSFontWeightUltraLight,
[uiDrawTextWeightUltraLight] = ourNSFontWeightThin, [uiDrawTextWeightUltraLight] = ourNSFontWeightThin,
[uiDrawTextWeightLight] = ourNSFontWeightLight, [uiDrawTextWeightLight] = ourNSFontWeightLight,
// for this one let's go between Light and Regular // for this one let's go between Light and Regular
// TODO figure out if we can rely on the order for these (and the one below) // we're doing nearest so if there happens to be an exact value hopefully it's close enough
[uiDrawTextWeightBook] = ourNSFontWeightLight + ((ourNSFontWeightRegular - ourNSFontWeightLight) / 2), [uiDrawTextWeightBook] = ourNSFontWeightLight + ((ourNSFontWeightRegular - ourNSFontWeightLight) / 2),
[uiDrawTextWeightNormal] = ourNSFontWeightRegular, [uiDrawTextWeightNormal] = ourNSFontWeightRegular,
[uiDrawTextWeightMedium] = ourNSFontWeightMedium, [uiDrawTextWeightMedium] = ourNSFontWeightMedium,
@ -174,7 +171,7 @@ static const CGFloat ctWeights[] = {
// Unfortunately there are still no named constants for these. // Unfortunately there are still no named constants for these.
// Let's just use normalized widths. // Let's just use normalized widths.
// As far as I can tell (OS X only has condensed fonts, not expanded fonts; TODO), regardless of condensed or expanded, negative means condensed and positive means expanded. // As far as I can tell (OS X only ships with condensed fonts, not expanded fonts; TODO), regardless of condensed or expanded, negative means condensed and positive means expanded.
// TODO verify this is correct // TODO verify this is correct
static const CGFloat ctStretches[] = { static const CGFloat ctStretches[] = {
[uiDrawTextStretchUltraCondensed] = -1.0, [uiDrawTextStretchUltraCondensed] = -1.0,
@ -199,7 +196,6 @@ struct closeness {
// Stupidity: CTFont requires an **exact match for the entire traits dictionary**, otherwise it will **drop ALL the traits**. // Stupidity: CTFont requires an **exact match for the entire traits dictionary**, otherwise it will **drop ALL the traits**.
// We have to implement the closest match ourselves. // We have to implement the closest match ourselves.
// Also we have to do this before adding the small caps flags, because the matching descriptors won't have those. // Also we have to do this before adding the small caps flags, because the matching descriptors won't have those.
// TODO document that font matching is closest match but the search method is OS defined
CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight weight, uiDrawTextItalic italic, uiDrawTextStretch stretch) CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight weight, uiDrawTextItalic italic, uiDrawTextStretch stretch)
{ {
CGFloat targetWeight; CGFloat targetWeight;
@ -254,7 +250,7 @@ CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight we
traits = CTFontDescriptorCopyAttribute(current, kCTFontTraitsAttribute); traits = CTFontDescriptorCopyAttribute(current, kCTFontTraitsAttribute);
if (traits == NULL) { if (traits == NULL) {
// couldn't get traits; be safe by ranking it lowest // couldn't get traits; be safe by ranking it lowest
// TODO figure out what the longest possible distances are // LONGTERM figure out what the longest possible distances are
closeness[i].weight = 3; closeness[i].weight = 3;
closeness[i].italic = 2; closeness[i].italic = 2;
closeness[i].stretch = 3; closeness[i].stretch = 3;
@ -277,13 +273,13 @@ CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight we
if (cfnum != NULL) { if (cfnum != NULL) {
CGFloat val; CGFloat val;
// TODO instead of complaining for this and width, should we just fall through to the default? // LONGTERM instead of complaining for this and width and possibly also symbolic traits above, should we just fall through to the default?
if (CFNumberGetValue(cfnum, kCFNumberCGFloatType, &val) == false) if (CFNumberGetValue(cfnum, kCFNumberCGFloatType, &val) == false)
complain("error getting weight value in matchTraits()"); complain("error getting weight value in matchTraits()");
closeness[i].weight = val - targetWeight; closeness[i].weight = val - targetWeight;
} else } else
// okay there's no weight key; let's try the literal meaning of the symbolic constant // okay there's no weight key; let's try the literal meaning of the symbolic constant
// TODO is the weight key guaranteed? // LONGTERM is the weight key guaranteed?
if ((symbolic & kCTFontBoldTrait) != 0) if ((symbolic & kCTFontBoldTrait) != 0)
closeness[i].weight = ourNSFontWeightBold - targetWeight; closeness[i].weight = ourNSFontWeightBold - targetWeight;
else else
@ -316,7 +312,7 @@ CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight we
// now try width // now try width
// TODO this does not seem to be enough for Skia's extended variants; the width trait is 0 but the Expanded flag is on // TODO this does not seem to be enough for Skia's extended variants; the width trait is 0 but the Expanded flag is on
// TODO verify the rest of this matrix // TODO verify the rest of this matrix (what matrix?)
cfnum = CFDictionaryGetValue(traits, kCTFontWidthTrait); cfnum = CFDictionaryGetValue(traits, kCTFontWidthTrait);
if (cfnum != NULL) { if (cfnum != NULL) {
CGFloat val; CGFloat val;
@ -326,7 +322,7 @@ CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight we
closeness[i].stretch = val - targetStretch; closeness[i].stretch = val - targetStretch;
} else } else
// okay there's no width key; let's try the literal meaning of the symbolic constant // okay there's no width key; let's try the literal meaning of the symbolic constant
// TODO is the width key guaranteed? // LONGTERM is the width key guaranteed?
if ((symbolic & kCTFontExpandedTrait) != 0) if ((symbolic & kCTFontExpandedTrait) != 0)
closeness[i].stretch = 1.0 - targetStretch; closeness[i].stretch = 1.0 - targetStretch;
else if ((symbolic & kCTFontCondensedTrait) != 0) else if ((symbolic & kCTFontCondensedTrait) != 0)
@ -354,7 +350,7 @@ CTFontDescriptorRef matchTraits(CTFontDescriptorRef against, uiDrawTextWeight we
const struct closeness *b = (const struct closeness *) bb; const struct closeness *b = (const struct closeness *) bb;
// via http://www.gnu.org/software/libc/manual/html_node/Comparison-Functions.html#Comparison-Functions // via http://www.gnu.org/software/libc/manual/html_node/Comparison-Functions.html#Comparison-Functions
// TODO is this really the best way? isn't it the same as if (*a < *b) return -1; if (*a > *b) return 1; return 0; ? // LONGTERM is this really the best way? isn't it the same as if (*a < *b) return -1; if (*a > *b) return 1; return 0; ?
return (a->distance > b->distance) - (a->distance < b->distance); return (a->distance > b->distance) - (a->distance < b->distance);
}); });
// and the first element of the sorted array is what we want // and the first element of the sorted array is what we want
@ -397,14 +393,7 @@ uiDrawTextFont *uiDrawLoadClosestFont(const uiDrawTextFontDescriptor *desc)
cfdesc = CTFontDescriptorCreateWithAttributes(attr); cfdesc = CTFontDescriptorCreateWithAttributes(attr);
// TODO release attr? // TODO release attr?
cfdesc = matchTraits(cfdesc, desc->Weight, desc->Italic, desc->Stretch); cfdesc = matchTraits(cfdesc, desc->Weight, desc->Italic, desc->Stretch);
/*TODO
attr = extractAttributes(cfdesc);
CFRelease(cfdesc);
// and NOW create the final descriptor
cfdesc = CTFontDescriptorCreateWithAttributes(attr);
// TODO release attr?
*/
// specify the initial size again just to be safe // specify the initial size again just to be safe
f = CTFontCreateWithFontDescriptor(cfdesc, desc->Size, NULL); f = CTFontCreateWithFontDescriptor(cfdesc, desc->Size, NULL);
// TODO release cfdesc? // TODO release cfdesc?
@ -425,7 +414,7 @@ uintptr_t uiDrawTextFontHandle(uiDrawTextFont *font)
void uiDrawTextFontDescribe(uiDrawTextFont *font, uiDrawTextFontDescriptor *desc) void uiDrawTextFontDescribe(uiDrawTextFont *font, uiDrawTextFontDescriptor *desc)
{ {
// TODO TODO TODO TODO // TODO
} }
// text sizes and user space points are identical: // text sizes and user space points are identical:
@ -473,9 +462,9 @@ uiDrawTextLayout *uiDrawNewTextLayout(const char *str, uiDrawTextFont *defaultFo
uiDrawTextLayoutSetWidth(layout, width); uiDrawTextLayoutSetWidth(layout, width);
// unfortunately the CFRanges for attributes expect UTF-16 codepoints // unfortunately the CFRanges for attributes expect UTF-16 codepoints
// we want full characters // we want graphemes
// fortunately CFStringGetRangeOfComposedCharactersAtIndex() is here for us // fortunately CFStringGetRangeOfComposedCharactersAtIndex() is here for us
// https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Strings/Articles/stringsClusters.html says that this does work on surrogate pairs (despite the name), and that this is the preferred function for this particular job anyway // https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Strings/Articles/stringsClusters.html says that this does work on all multi-codepoint graphemes (despite the name), and that this is the preferred function for this particular job anyway
backing = CFAttributedStringGetString(layout->mas); backing = CFAttributedStringGetString(layout->mas);
n = CFStringGetLength(backing); n = CFStringGetLength(backing);
// allocate one extra, just to be safe // allocate one extra, just to be safe
@ -493,7 +482,6 @@ uiDrawTextLayout *uiDrawNewTextLayout(const char *str, uiDrawTextFont *defaultFo
// and set the last one // and set the last one
layout->charsToRanges[j].location = i; layout->charsToRanges[j].location = i;
layout->charsToRanges[j].length = 0; layout->charsToRanges[j].length = 0;
// TODO how will this affect drawing things that aren't surrogate pairs?
return layout; return layout;
} }
@ -548,8 +536,8 @@ static void freeFramesetter(struct framesetter *fs)
CFRelease(fs->fs); CFRelease(fs->fs);
} }
// TODO document that the extent width can be greater than the requested width if the requested width is small enough that only one character can fit // LONGTERM allow line separation and leading to be factored into a wrapping text layout
// TODO figure out how line separation and leading plays into this
// TODO reconcile differences in character wrapping on platforms // TODO reconcile differences in character wrapping on platforms
void uiDrawTextLayoutExtents(uiDrawTextLayout *layout, double *width, double *height) void uiDrawTextLayoutExtents(uiDrawTextLayout *layout, double *width, double *height)
{ {
@ -609,15 +597,15 @@ void doDrawText(CGContextRef c, CGFloat cheight, double x, double y, uiDrawTextL
CGContextRestoreGState(c); CGContextRestoreGState(c);
} }
// TODO provide an equivalent to CTLineGetTypographicBounds() on uiDrawTextLayout? // LONGTERM provide an equivalent to CTLineGetTypographicBounds() on uiDrawTextLayout?
// TODO keep this for TODO and documentation purposes // LONGTERM keep this for later features and documentation purposes
#if 0 #if 0
w = CTLineGetTypographicBounds(line, &ascent, &descent, NULL); w = CTLineGetTypographicBounds(line, &ascent, &descent, NULL);
// though CTLineGetTypographicBounds() returns 0 on error, it also returns 0 on an empty string, so we can't reasonably check for error // though CTLineGetTypographicBounds() returns 0 on error, it also returns 0 on an empty string, so we can't reasonably check for error
CFRelease(line); CFRelease(line);
// TODO provide a way to get the image bounds as a separate function later // LONGTERM provide a way to get the image bounds as a separate function later
bounds = CTLineGetImageBounds(line, c); bounds = CTLineGetImageBounds(line, c);
// though CTLineGetImageBounds() returns CGRectNull on error, it also returns CGRectNull on an empty string, so we can't reasonably check for error // though CTLineGetImageBounds() returns CGRectNull on error, it also returns CGRectNull on an empty string, so we can't reasonably check for error

10
doc/drawtext
View File

@ -1 +1,11 @@
on some unix systems, alpha blending fonts may not be available; this depends on your installed version of pango and is determined at runtime by libui on some unix systems, alpha blending fonts may not be available; this depends on your installed version of pango and is determined at runtime by libui
uiDrawTextLayoutExtents: document that the extent width can be greater than the requested width if the requested width is small enough that only one character can fit
font matching is closest match but the search method is OS defined
weight names in libui do not necessarily line up with their OS names