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/*
* Copyright 2015 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 "SkColorPriv.h"
#include "SkLightingShader.h"
static SkBitmap make_checkerboard(int texSize) {
SkBitmap bitmap;
bitmap.allocN32Pixels(texSize, texSize);
SkCanvas canvas(bitmap);
sk_tool_utils::draw_checkerboard(&canvas,
sk_tool_utils::color_to_565(0x0),
sk_tool_utils::color_to_565(0xFF804020),
2);
return bitmap;
}
// Create a hemispherical normal map
static SkBitmap make_hemi_normalmap(int texSize) {
SkBitmap hemi;
hemi.allocN32Pixels(texSize, texSize);
for (int y = 0; y < texSize; ++y) {
for (int x = 0; x < texSize; ++x) {
SkScalar locX = (x + 0.5f - texSize/2.0f) / (texSize/2.0f);
SkScalar locY = (y + 0.5f - texSize/2.0f) / (texSize/2.0f);
SkScalar locZ = locX * locX + locY * locY;
if (locZ >= 1.0f) {
locX = 0.0f;
locY = 0.0f;
locZ = 0.0f;
}
locZ = sqrtf(1.0f - locZ);
unsigned char r = static_cast<unsigned char>((0.5f * locX + 0.5f) * 255);
unsigned char g = static_cast<unsigned char>((-0.5f * locY + 0.5f) * 255);
unsigned char b = static_cast<unsigned char>((0.5f * locZ + 0.5f) * 255);
*hemi.getAddr32(x, y) = SkPackARGB32(0xFF, r, g, b);
}
}
return hemi;
}
// Create a truncated pyramid normal map
static SkBitmap make_frustum_normalmap(int texSize) {
SkBitmap frustum;
frustum.allocN32Pixels(texSize, texSize);
SkIRect inner = SkIRect::MakeWH(texSize, texSize);
inner.inset(texSize/4, texSize/4);
SkPoint3 norm;
const SkPoint3 left = SkPoint3::Make(-SK_ScalarRoot2Over2, 0.0f, SK_ScalarRoot2Over2);
const SkPoint3 up = SkPoint3::Make(0.0f, -SK_ScalarRoot2Over2, SK_ScalarRoot2Over2);
const SkPoint3 right = SkPoint3::Make(SK_ScalarRoot2Over2, 0.0f, SK_ScalarRoot2Over2);
const SkPoint3 down = SkPoint3::Make(0.0f, SK_ScalarRoot2Over2, SK_ScalarRoot2Over2);
for (int y = 0; y < texSize; ++y) {
for (int x = 0; x < texSize; ++x) {
if (inner.contains(x, y)) {
norm.set(0.0f, 0.0f, 1.0f);
} else {
SkScalar locX = x + 0.5f - texSize/2.0f;
SkScalar locY = y + 0.5f - texSize/2.0f;
if (locX >= 0.0f) {
if (locY > 0.0f) {
norm = locX >= locY ? right : down; // LR corner
} else {
norm = locX > -locY ? right : up; // UR corner
}
} else {
if (locY > 0.0f) {
norm = -locX > locY ? left : down; // LL corner
} else {
norm = locX > locY ? up : left; // UL corner
}
}
}
SkASSERT(SkScalarNearlyEqual(norm.length(), 1.0f));
unsigned char r = static_cast<unsigned char>((0.5f * norm.fX + 0.5f) * 255);
unsigned char g = static_cast<unsigned char>((-0.5f * norm.fY + 0.5f) * 255);
unsigned char b = static_cast<unsigned char>((0.5f * norm.fZ + 0.5f) * 255);
*frustum.getAddr32(x, y) = SkPackARGB32(0xFF, r, g, b);
}
}
return frustum;
}
namespace skiagm {
// This GM exercises lighting shaders.
class LightingShaderGM : public GM {
public:
LightingShaderGM() {
this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
fLight.fColor = SkColor3f::Make(1.0f, 1.0f, 1.0f);
fLight.fDirection.fX = 0.0f;
fLight.fDirection.fY = 0.0f;
fLight.fDirection.fZ = 1.0f;
fAmbient = SkColor3f::Make(0.1f, 0.1f, 0.1f);
}
protected:
SkString onShortName() override {
return SkString("lightingshader");
}
SkISize onISize() override {
return SkISize::Make(kGMSize, kGMSize);
}
void onOnceBeforeDraw() override {
fDiffuse = make_checkerboard(kTexSize);
fHemiNormalMap = make_hemi_normalmap(kTexSize);
fFrustumNormalMap = make_frustum_normalmap(kTexSize);
}
void drawRect(SkCanvas* canvas, const SkRect& r, bool hemi) {
SkRect bitmapBounds = SkRect::MakeIWH(fDiffuse.width(), fDiffuse.height());
SkMatrix matrix;
matrix.setRectToRect(bitmapBounds, r, SkMatrix::kFill_ScaleToFit);
SkAutoTUnref<SkShader> fShader(SkLightingShader::Create(
fDiffuse,
hemi ? fHemiNormalMap : fFrustumNormalMap,
fLight, fAmbient,
&matrix));
SkPaint paint;
paint.setShader(fShader);
canvas->drawRect(r, paint);
}
void onDraw(SkCanvas* canvas) override {
SkRect r = SkRect::MakeWH(SkIntToScalar(kTexSize), SkIntToScalar(kTexSize));
this->drawRect(canvas, r, true);
r.offset(kGMSize - kTexSize, 0);
this->drawRect(canvas, r, false);
r.offset(0, kGMSize - kTexSize);
this->drawRect(canvas, r, true);
r.offset(kTexSize - kGMSize, 0);
this->drawRect(canvas, r, false);
}
private:
static const int kTexSize = 128;
static const int kGMSize = 512;
SkBitmap fDiffuse;
SkBitmap fHemiNormalMap;
SkBitmap fFrustumNormalMap;
SkLightingShader::Light fLight;
SkColor3f fAmbient;
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM( return SkNEW(LightingShaderGM); )
}
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