skia2/gm/lcdtext.cpp
bungeman 6f9f2591c1 Fix alpha coverage for lerp_565 stage.
Like three gray with alpha blends and taking the max alpha.

Change-Id: I104c84f784979030744127f8f66905ad9d1bdf0e
Reviewed-on: https://skia-review.googlesource.com/15898
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
2017-05-10 18:20:25 +00:00

161 lines
4.5 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Tests text rendering with LCD and subpixel rendering turned on and off.
*/
#include "gm.h"
#include "sk_tool_utils.h"
#include "SkCanvas.h"
#include "SkPicture.h"
#include "SkPictureImageFilter.h"
#include "SkPictureRecorder.h"
#include "SkSurface.h"
class LcdTextGM : public skiagm::GM {
public:
LcdTextGM() {
const int pointSize = 36;
textHeight = SkIntToScalar(pointSize);
}
protected:
SkString onShortName() {
SkString name("lcdtext");
name.append(sk_tool_utils::major_platform_os_name());
return name;
}
SkISize onISize() { return SkISize::Make(640, 480); }
virtual void onDraw(SkCanvas* canvas) {
y = textHeight;
drawText(canvas, SkString("TEXT: SubpixelTrue LCDRenderTrue"),
true, true);
drawText(canvas, SkString("TEXT: SubpixelTrue LCDRenderFalse"),
true, false);
drawText(canvas, SkString("TEXT: SubpixelFalse LCDRenderTrue"),
false, true);
drawText(canvas, SkString("TEXT: SubpixelFalse LCDRenderFalse"),
false, false);
}
void drawText(SkCanvas* canvas, const SkString& string,
bool subpixelTextEnabled, bool lcdRenderTextEnabled) {
SkPaint paint;
paint.setColor(SK_ColorBLACK);
paint.setDither(true);
paint.setAntiAlias(true);
paint.setSubpixelText(subpixelTextEnabled);
paint.setLCDRenderText(lcdRenderTextEnabled);
paint.setTextSize(textHeight);
canvas->drawString(string, 0, y, paint);
y += textHeight;
}
private:
typedef skiagm::GM INHERITED;
SkScalar y, textHeight;
};
/*
* Skia will automatically disable LCD requests if the total size exceeds some limit
* (hard coded in this test for now, as it is now avaiable as an API)
*
* Test this both by changing "textsize" and by changing the computed size (textsize * CTM)
*/
class LcdTextSizeGM : public skiagm::GM {
enum {
kLCDTextSizeLimit = 48
};
static void ScaleAbout(SkCanvas* canvas, SkScalar sx, SkScalar sy, SkScalar px, SkScalar py) {
SkMatrix m;
m.setScale(sx, sy, px, py);
canvas->concat(m);
}
public:
LcdTextSizeGM() {}
protected:
SkString onShortName() {
return SkString("lcdtextsize");
}
SkISize onISize() { return SkISize::Make(320, 120); }
virtual void onDraw(SkCanvas* canvas) {
const char* lcd_text = "LCD";
const char* gray_text = "GRAY";
SkPaint paint;
paint.setAntiAlias(true);
paint.setLCDRenderText(true);
const struct {
SkPoint fLoc;
SkScalar fTextSize;
SkScalar fScale;
const char* fText;
} rec[] = {
{ { 10, 50 }, kLCDTextSizeLimit - 1, 1, lcd_text },
{ { 160, 50 }, kLCDTextSizeLimit + 1, 1, gray_text },
{ { 10, 100 }, kLCDTextSizeLimit / 2, 1.99f, lcd_text },
{ { 160, 100 }, kLCDTextSizeLimit / 2, 2.01f, gray_text },
};
for (size_t i = 0; i < SK_ARRAY_COUNT(rec); ++i) {
const SkPoint loc = rec[i].fLoc;
SkAutoCanvasRestore acr(canvas, true);
paint.setTextSize(rec[i].fTextSize);
ScaleAbout(canvas, rec[i].fScale, rec[i].fScale, loc.x(), loc.y());
canvas->drawString(rec[i].fText, loc.x(), loc.y(), paint);
}
}
private:
typedef skiagm::GM INHERITED;
};
DEF_GM( return new LcdTextGM; )
DEF_GM( return new LcdTextSizeGM; )
///////////////////////////////////////////////////////////////////////////////////////////////////
DEF_SIMPLE_GM(savelayer_lcdtext, canvas, 620, 260) {
SkPaint paint;
paint.setAntiAlias(true);
paint.setLCDRenderText(true);
paint.setTextSize(20);
canvas->drawString("Hamburgefons", 30, 30, paint);
const bool gPreserveLCDText[] = { false, true };
canvas->translate(0, 20);
for (auto preserve : gPreserveLCDText) {
preserve ? canvas->saveLayerPreserveLCDTextRequests(nullptr, nullptr)
: canvas->saveLayer(nullptr, nullptr);
canvas->drawString("Hamburgefons", 30, 60, paint);
SkPaint p;
p.setColor(0xFFCCCCCC);
canvas->drawRect(SkRect::MakeLTRB(25, 70, 200, 100), p);
canvas->drawString("Hamburgefons", 30, 90, paint);
canvas->restore();
canvas->translate(0, 80);
}
}