Am I usingJava 8 的一个功能或misusing it?
请参阅下面的代码和解释以了解为什么选择这样。
public interface Drawable {
public void compileProgram();
public Program getProgram();
default public boolean isTessellated() {
return false;
}
default public boolean isInstanced() {
return false;
}
default public int getInstancesCount() {
return 0;
}
public int getDataSize();
public FloatBuffer putData(final FloatBuffer dataBuffer);
public int getDataMode();
public boolean isShadowReceiver();
public boolean isShadowCaster(); //TODO use for AABB calculations
default public void drawDepthPass(final int offset, final Program depthNormalProgram, final Program depthTessellationProgram) {
Program depthProgram = (isTessellated()) ? depthTessellationProgram : depthNormalProgram;
if (isInstanced()) {
depthProgram.use().drawArraysInstanced(getDataMode(), offset, getDataSize(), getInstancesCount());
}
else {
depthProgram.use().drawArrays(getDataMode(), offset, getDataSize());
}
}
default public void draw(final int offset) {
if (isInstanced()) {
getProgram().use().drawArraysInstanced(getDataMode(), offset, getDataSize(), getInstancesCount());
}
else {
getProgram().use().drawArrays(getDataMode(), offset, getDataSize());
}
}
default public void delete() {
getProgram().delete();
}
public static int countDataSize(final Collection<Drawable> drawables) {
return drawables.stream()
.mapToInt(Drawable::getDataSize)
.sum();
}
public static FloatBuffer putAllData(final List<Drawable> drawables) {
FloatBuffer dataBuffer = BufferUtils.createFloatBuffer(countDataSize(drawables) * 3);
drawables.stream().forEachOrdered(drawable -> drawable.putData(dataBuffer));
return (FloatBuffer)dataBuffer.clear();
}
public static void drawAllDepthPass(final List<Drawable> drawables, final Program depthNormalProgram, final Program depthTessellationProgram) {
int offset = 0;
for (Drawable drawable : drawables) {
if (drawable.isShadowReceiver()) {
drawable.drawDepthPass(offset, depthNormalProgram, depthTessellationProgram);
}
offset += drawable.getDataSize(); //TODO count offset only if not shadow receiver?
}
}
public static void drawAll(final List<Drawable> drawables) {
int offset = 0;
for (Drawable drawable : drawables) {
drawable.draw(offset);
offset += drawable.getDataSize();
}
}
public static void deleteAll(final List<Drawable> drawables) {
drawables.stream().forEach(Drawable::delete);
}
}
public interface TessellatedDrawable extends Drawable {
@Override
default public boolean isTessellated() {
return true;
}
}
public interface InstancedDrawable extends Drawable {
@Override
default public boolean isInstanced() {
return true;
}
@Override
public int getInstancesCount();
}
public class Box implements TessellatedDrawable, InstancedDrawable {
//<editor-fold defaultstate="collapsed" desc="keep-imports">
static {
int KEEP_LWJGL_IMPORTS = GL_2_BYTES | GL_ALIASED_LINE_WIDTH_RANGE | GL_ACTIVE_TEXTURE | GL_BLEND_COLOR | GL_ARRAY_BUFFER | GL_ACTIVE_ATTRIBUTE_MAX_LENGTH | GL_COMPRESSED_SLUMINANCE | GL_ALPHA_INTEGER | GL_ACTIVE_UNIFORM_BLOCK_MAX_NAME_LENGTH | GL_ALREADY_SIGNALED | GL_ANY_SAMPLES_PASSED | GL_ACTIVE_SUBROUTINE_UNIFORM_MAX_LENGTH | GL_ACTIVE_PROGRAM | GL_ACTIVE_ATOMIC_COUNTER_BUFFERS | GL_ACTIVE_RESOURCES | GL_BUFFER_IMMUTABLE_STORAGE;
int KEEP_OWN_IMPORTS = UNIFORM_PROJECTION_MATRIX.getLocation() | VS_POSITION.getLocation();
}
//</editor-fold>
private FloatBuffer data;
private Program program;
private final float width, height, depth;
public Box(final float width, final float height, final float depth) {
this.width = width;
this.height = height;
this.depth = depth;
data = generateBox();
data.clear();
}
@Override
public void compileProgram() {
program = new Program(
new VertexShader("data/shaders/box.vs.glsl").compile(),
new FragmentShader("data/shaders/box.fs.glsl").compile()
).compile().usingUniforms(
UNIFORM_MODEL_MATRIX,
UNIFORM_VIEW_MATRIX,
UNIFORM_PROJECTION_MATRIX,
UNIFORM_SHADOW_MATRIX
);
}
@Override
public int getInstancesCount() {
return 100;
}
@Override
public Program getProgram() {
return program;
}
@Override
public int getDataSize() {
return 6 * 6;
}
@Override
public FloatBuffer putData(final FloatBuffer dataBuffer) {
FloatBuffer returnData = dataBuffer.put(data);
data.clear(); //clear to reset data state
return returnData;
}
@Override
public int getDataMode() {
return GL_TRIANGLES;
}
@Override
public boolean isShadowReceiver() {
return true;
}
@Override
public boolean isShadowCaster() {
return true;
}
private FloatBuffer generateBox() {
FloatBuffer boxData = BufferUtils.createFloatBuffer(6 * 6 * 3);
//put data into boxData
return (FloatBuffer)boxData.clear();
}
}
首先是我如何得到这段代码的步骤：
我从Drawable接口和每个实现都有自己的drawDepthPass, draw and delete方法。
重构delete to a default方法简单、琐碎，应该不会出错。
然而能够重构drawDepthPass and draw我需要访问是否Drawable被细分和/或实例化，所以我添加了公共（非默认） 方法isTessellated(), isInstanced() and getInstancesCount().
然后我发现这会有点麻烦，因为我们程序员很懒，在每个地方都实现它们Drawable.
结果我添加了default方法Drawable，给出最基本的行为Drawable.
然后我发现我仍然很懒，也不想为镶嵌和实例化变体手动实现它。
所以我创建了TessellatedDrawable and InstancedDrawable提供default isTessellated() and isInstanced()分别。并且在InstancedDrawable我撤销了default实施getInstancesCount().
结果我可以得到以下结果：
- Normal
Drawable: public class A implements Drawable
- 镶嵌的
Drawable: public class A implements TessellatedDrawable
- 实例化
Drawable: public class A implements InstancedDrawable
- 镶嵌和实例化
Drawable: public class A implements InstancedDrawable, TessellatedDrawable.
只是为了向您保证，这一切都可以正常编译并运行，implements InstancedDrawable, TessellatedDrawableJava 8 完美地处理了这个问题，因为功能应该来自哪个接口没有任何歧义。
现在开始我自己的 OOP 设计评估：
- Every
Drawable实际上是一个Drawable, so Collection<Drawable>不会破裂。
- 可以对所有的进行分组
TessellatedDrawable and/or InstancedDrawable，与具体如何实施无关。
我的其他想法：
我还考虑过构建器模式，但是这是在创建某个对象的许多唯一实例时使用的模式，这不是我们在这里所做的，也不是关于对象的构造函数的。
所以第一个也是最后一个问题是：我是usingJava 8 的一个功能或misusing it?
