AuroraMiddleware/skia2
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add subpixel tweaking

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Bug: skia:
Change-Id: Ibf5fdf00694e29cb3f3268ea577a8d317e6c7614
Reviewed-on: https://skia-review.googlesource.com/c/193697
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
This commit is contained in:
Mike Reed 2019-02-21 10:42:07 -05:00
parent f0aefa2bc1
commit 11bfaf160b
1 changed files with 30 additions and 8 deletions
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38
gm/mac_aa_explorer.cpp
View File

@ -12,6 +12,25 @@
#import <ApplicationServices/ApplicationServices.h>
static void std_cg_setup(CGContextRef ctx) {
CGContextSetAllowsFontSubpixelQuantization(ctx, false);
CGContextSetShouldSubpixelQuantizeFonts(ctx, false);
// Because CG always draws from the horizontal baseline,
// if there is a non-integral translation from the horizontal origin to the vertical origin,
// then CG cannot draw the glyph in the correct location without subpixel positioning.
CGContextSetAllowsFontSubpixelPositioning(ctx, true);
CGContextSetShouldSubpixelPositionFonts(ctx, true);
CGContextSetAllowsFontSmoothing(ctx, true);
CGContextSetShouldAntialias(ctx, true);
CGContextSetTextDrawingMode(ctx, kCGTextFill);
// Draw black on white to create mask. (Special path exists to speed this up in CG.)
CGContextSetGrayFillColor(ctx, 0.0f, 1.0f);
}
static CGContextRef make_cg_ctx(const SkPixmap& pm) {
CGBitmapInfo info;
CGColorSpaceRef cs;
@ -32,14 +51,15 @@ static CGContextRef make_cg_ctx(const SkPixmap& pm) {
default:
return nullptr;
}
return CGBitmapContextCreate(pm.writable_addr(), pm.width(), pm.height(), 8, pm.rowBytes(),
cs, info);
auto ctx = CGBitmapContextCreate(pm.writable_addr(), pm.width(), pm.height(), 8, pm.rowBytes(),
cs, info);
std_cg_setup(ctx);
return ctx;
}
static void test_mac_fonts(SkCanvas* canvas, SkScalar size) {
static void test_mac_fonts(SkCanvas* canvas, SkScalar size, SkScalar xpos) {
int w = 32;
int h = 32;
bool shouldAA = true;
canvas->scale(10, 10);
SkScalar y = 1;
@ -50,15 +70,13 @@ static void test_mac_fonts(SkCanvas* canvas, SkScalar size) {
SkPixmap pm;
surf->peekPixels(&pm);
CGContextRef ctx = make_cg_ctx(pm);
CGContextSetAllowsFontSmoothing(ctx, true);
CGContextSetShouldAntialias(ctx, shouldAA);
CGContextSelectFont(ctx, "Helvetica", size, kCGEncodingMacRoman);
SkScalar x = 1;
for (bool smooth : {false, true}) {
surf->getCanvas()->clear(ct == kGray_8_SkColorType ? 0xFFFFFFFF : 0);
CGContextSetShouldSmoothFonts(ctx, smooth);
CGContextShowTextAtPoint(ctx, 2, 2, "A", 1);
CGContextShowTextAtPoint(ctx, 2 + xpos, 2, "A", 1);
surf->draw(canvas, x, y, nullptr);
x += pm.width();
@ -69,13 +87,15 @@ static void test_mac_fonts(SkCanvas* canvas, SkScalar size) {
class MacAAFontsGM : public skiagm::GM {
SkScalar fSize = 16;
SkScalar fXPos = 0;
public:
MacAAFontsGM() {}
~MacAAFontsGM() override {}
protected:
DrawResult onDraw(SkCanvas* canvas, SkString* errorMsg) override {
test_mac_fonts(canvas, fSize);
test_mac_fonts(canvas, fSize, fXPos);
return DrawResult::kOk;
}
@ -88,6 +108,8 @@ protected:
switch (uni) {
case 'i': fSize += 1; return true;
case 'k': fSize -= 1; return true;
case 'j': fXPos -= 1.0f/16; return true;
case 'l': fXPos += 1.0f/16; return true;
default: break;
}
return false;