blob: c5e43c8130f5bb61264f084e7c34aa175ab0efa3 [file] [log] [blame]
/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm.h"
#include "sk_tool_utils.h"
#include "SkCanvas.h"
#include "SkFont.h"
#include "SkTypeface.h"
/* This test tries to define the effect of using hairline strokes on text.
* Provides non-hairline images for reference and consistency checks.
* glyph_pos_(h/n)_(s/f/b)
* -> test hairline/non-hairline stroke/fill/stroke+fill.
*/
constexpr SkScalar kTextHeight = 14.0f;
constexpr char kText[] = "Proportional Hamburgefons #% fi";
static void drawTestCase(SkCanvas* canvas,
SkScalar textScale,
SkScalar strokeWidth,
SkPaint::Style strokeStyle);
static void draw_gm(SkCanvas* canvas,
SkScalar strokeWidth,
SkPaint::Style strokeStyle) {
// There's a black pixel at 40, 40 for reference.
canvas->drawPoint(40, 40, SkPaint());
// Two reference images.
canvas->translate(50.0f, 50.0f);
drawTestCase(canvas, 1.0f, strokeWidth, strokeStyle);
canvas->translate(0.0f, 50.0f);
drawTestCase(canvas, 3.0f, strokeWidth, strokeStyle);
// Uniform scaling test.
canvas->translate(0.0f, 100.0f);
canvas->save();
canvas->scale(3.0f, 3.0f);
drawTestCase(canvas, 1.0f, strokeWidth, strokeStyle);
canvas->restore();
// Non-uniform scaling test.
canvas->translate(0.0f, 100.0f);
canvas->save();
canvas->scale(3.0f, 6.0f);
drawTestCase(canvas, 1.0f, strokeWidth, strokeStyle);
canvas->restore();
// Skew test.
canvas->translate(0.0f, 80.0f);
canvas->save();
canvas->scale(3.0f, 3.0f);
SkMatrix skew;
skew.setIdentity();
skew.setSkewX(8.0f / 25.0f);
skew.setSkewY(2.0f / 25.0f);
canvas->concat(skew);
drawTestCase(canvas, 1.0f, strokeWidth, strokeStyle);
canvas->restore();
// Perspective test.
canvas->translate(0.0f, 80.0f);
canvas->save();
SkMatrix perspective;
perspective.setIdentity();
perspective.setPerspX(-SkScalarInvert(340));
perspective.setSkewX(8.0f / 25.0f);
perspective.setSkewY(2.0f / 25.0f);
canvas->concat(perspective);
drawTestCase(canvas, 1.0f, strokeWidth, strokeStyle);
canvas->restore();
}
static void drawTestCase(SkCanvas* canvas,
SkScalar textScale,
SkScalar strokeWidth,
SkPaint::Style strokeStyle) {
SkPaint paint;
paint.setColor(SK_ColorBLACK);
paint.setAntiAlias(true);
paint.setStrokeWidth(strokeWidth);
paint.setStyle(strokeStyle);
SkFont font(sk_tool_utils::create_portable_typeface(), kTextHeight * textScale);
// This demonstrates that we can not measure the text if
// there's a device transform. The canvas total matrix will
// end up being a device transform.
bool drawRef = !(canvas->getTotalMatrix().getType() &
~(SkMatrix::kIdentity_Mask | SkMatrix::kTranslate_Mask));
SkRect bounds;
if (drawRef) {
SkScalar advance = font.measureText(kText, sizeof(kText) - 1, kUTF8_SkTextEncoding,
&bounds, &paint);
paint.setStrokeWidth(0.0f);
paint.setStyle(SkPaint::kStroke_Style);
// Green box is the measured text bounds.
paint.setColor(SK_ColorGREEN);
canvas->drawRect(bounds, paint);
// Red line is the measured advance from the 0,0 of the text position.
paint.setColor(SK_ColorRED);
canvas->drawLine(0.0f, 0.0f, advance, 0.0f, paint);
}
// Black text is the testcase, eg. the text.
paint.setColor(SK_ColorBLACK);
paint.setStrokeWidth(strokeWidth);
paint.setStyle(strokeStyle);
canvas->drawSimpleText(kText, sizeof(kText) - 1, kUTF8_SkTextEncoding, 0.0f, 0.0f, font, paint);
if (drawRef) {
const size_t len = sizeof(kText) - 1;
SkGlyphID glyphs[len];
const int count = font.textToGlyphs(kText, len, kUTF8_SkTextEncoding, glyphs, len);
SkScalar widths[len]; // len is conservative. we really only need 'count'
font.getWidthsBounds(glyphs, count, widths, nullptr, &paint);
paint.setStrokeWidth(0.0f);
paint.setStyle(SkPaint::kStroke_Style);
// Magenta lines are the positions for the characters.
paint.setColor(SK_ColorMAGENTA);
SkScalar w = bounds.x();
for (size_t i = 0; i < sizeof(kText) - 1; ++i) {
canvas->drawLine(w, 0.0f, w, 5.0f, paint);
w += widths[i];
}
}
}
DEF_SIMPLE_GM(glyph_pos_h_b, c, 800, 600) {
draw_gm(c, 0.0f, SkPaint::kStrokeAndFill_Style);
}
DEF_SIMPLE_GM(glyph_pos_n_b, c, 800, 600) {
draw_gm(c, 1.2f, SkPaint::kStrokeAndFill_Style);
}
DEF_SIMPLE_GM(glyph_pos_h_s, c, 800, 600) {
draw_gm(c, 0.0f, SkPaint::kStroke_Style);
}
DEF_SIMPLE_GM(glyph_pos_n_s, c, 800, 600) {
draw_gm(c, 1.2f, SkPaint::kStroke_Style);
}
DEF_SIMPLE_GM(glyph_pos_h_f, c, 800, 600) {
draw_gm(c, 0.0f, SkPaint::kFill_Style);
}
DEF_SIMPLE_GM(glyph_pos_n_f, c, 800, 600) {
draw_gm(c, 1.2f, SkPaint::kFill_Style);
}