Exposed SkMeshSpecification

Exposed SkMeshSpecification through MeshSpecification, exposing Make
methods as well as constructing a Attribute and Varying data classes.

Bug: b/254354404
Test: build hwui
Change-Id: I1040bde091575ac4bb786f7600d016b7c9168831
diff --git a/graphics/java/android/graphics/MeshSpecification.java b/graphics/java/android/graphics/MeshSpecification.java
new file mode 100644
index 0000000..b27c5e0
--- /dev/null
+++ b/graphics/java/android/graphics/MeshSpecification.java
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.graphics;
+
+import android.annotation.IntDef;
+
+import libcore.util.NativeAllocationRegistry;
+
+/**
+ * Class responsible for holding specifications for {@link Mesh} creations. This class
+ * generates a {@link MeshSpecification} via the Make method, where multiple parameters to set up
+ * the mesh are supplied, including attributes, vertex stride, varyings, and
+ * vertex/fragment shaders. There are also additional methods to provide an optional
+ * {@link ColorSpace} as well as an alpha type.
+ *
+ * Note that there are several limitations on various mesh specifications:
+ * 1. The max amount of attributes allowed is 8.
+ * 2. The offset alignment length is 4 bytes.
+ * 2. The max stride length is 1024.
+ * 3. The max amount of varyings is 6.
+ *
+ * These should be kept in mind when generating a mesh specification, as exceeding them will
+ * lead to errors.
+ *
+ * @hide
+ */
+public class MeshSpecification {
+    private long mNativeMeshSpec;
+
+    /**
+     * Constants for {@link #make(Attribute[], int, Varying[], String, String, ColorSpace, int)}
+     * to determine alpha type
+     */
+    @IntDef({UNKNOWN, OPAQUE, PREMUL, UNPREMULT})
+    public @interface AlphaType {
+    }
+
+    public static final int UNKNOWN = 0;
+    public static final int OPAQUE = 1;
+    public static final int PREMUL = 2;
+    public static final int UNPREMULT = 3;
+
+    /**
+     * Constants for {@link Attribute} and {@link Varying} for determining the data type.
+     */
+    @IntDef({FLOAT, FLOAT2, FLOAT3, FLOAT4, UBYTE4})
+    public @interface Type {
+    }
+
+    public static final int FLOAT = 0;
+    public static final int FLOAT2 = 1;
+    public static final int FLOAT3 = 2;
+    public static final int FLOAT4 = 3;
+    public static final int UBYTE4 = 4;
+
+    /**
+     * Data class to represent a single attribute in a shader. Note that type parameter must be
+     * one of {@link #FLOAT}, {@link #FLOAT2}, {@link #FLOAT3}, {@link #FLOAT4}, or {@link #UBYTE4}.
+     */
+    public static class Attribute {
+        @Type
+        private int mType;
+        private int mOffset;
+        private String mName;
+
+        public Attribute(@Type int type, int offset, String name) {
+            mType = type;
+            mOffset = offset;
+            mName = name;
+        }
+    }
+
+    /**
+     * Data class to represent a single varying variable. Note that type parameter must be
+     * one of {@link #FLOAT}, {@link #FLOAT2}, {@link #FLOAT3}, {@link #FLOAT4}, or {@link #UBYTE4}.
+     */
+    public static class Varying {
+        @Type
+        private int mType;
+        private String mName;
+
+        public Varying(@Type int type, String name) {
+            mType = type;
+            mName = name;
+        }
+    }
+
+    private static class MeshSpecificationHolder {
+        public static final NativeAllocationRegistry MESH_SPECIFICATION_REGISTRY =
+                NativeAllocationRegistry.createMalloced(
+                        MeshSpecification.class.getClassLoader(), nativeGetFinalizer());
+    }
+
+    /**
+     * Creates a {@link MeshSpecification} object.
+     *
+     * @param attributes     list of attributes represented by {@link Attribute}. Can hold a max of
+     *                       8.
+     * @param vertexStride   length of vertex stride. Max of 1024 is accepted.
+     * @param varyings       List of varyings represented by {@link Varying}. Can hold a max of 6.
+     * @param vertexShader   vertex shader to be supplied to the mesh.
+     * @param fragmentShader fragment shader to be suppied to the mesh.
+     * @return {@link MeshSpecification} object for use when creating {@link Mesh}
+     */
+    public static MeshSpecification make(Attribute[] attributes, int vertexStride,
+            Varying[] varyings, String vertexShader, String fragmentShader) {
+        long nativeMeshSpec =
+                nativeMake(attributes, vertexStride, varyings, vertexShader, fragmentShader);
+        if (nativeMeshSpec == 0) {
+            throw new IllegalArgumentException("MeshSpecification construction failed");
+        }
+        return new MeshSpecification(nativeMeshSpec);
+    }
+
+    /**
+     * Creates a {@link MeshSpecification} object.
+     *
+     * @param attributes     list of attributes represented by {@link Attribute}. Can hold a max of
+     *                       8.
+     * @param vertexStride   length of vertex stride. Max of 1024 is accepted.
+     * @param varyings       List of varyings represented by {@link Varying}. Can hold a max of
+     *                       6.
+     * @param vertexShader   vertex shader to be supplied to the mesh.
+     * @param fragmentShader fragment shader to be supplied to the mesh.
+     * @param colorSpace     {@link ColorSpace} to tell what color space to work in.
+     * @return {@link MeshSpecification} object for use when creating {@link Mesh}
+     */
+    public static MeshSpecification make(Attribute[] attributes, int vertexStride,
+            Varying[] varyings, String vertexShader, String fragmentShader, ColorSpace colorSpace) {
+        long nativeMeshSpec = nativeMakeWithCS(attributes, vertexStride, varyings, vertexShader,
+                fragmentShader, colorSpace.getNativeInstance());
+        if (nativeMeshSpec == 0) {
+            throw new IllegalArgumentException("MeshSpecification construction failed");
+        }
+        return new MeshSpecification(nativeMeshSpec);
+    }
+
+    /**
+     * Creates a {@link MeshSpecification} object.
+     *
+     * @param attributes     list of attributes represented by {@link Attribute}. Can hold a max of
+     *                       8.
+     * @param vertexStride   length of vertex stride. Max of 1024 is accepted.
+     * @param varyings       List of varyings represented by {@link Varying}. Can hold a max of 6.
+     * @param vertexShader   vertex shader code to be supplied to the mesh.
+     * @param fragmentShader fragment shader code to be suppied to the mesh.
+     * @param colorSpace     {@link ColorSpace} to tell what color space to work in.
+     * @param alphaType      Describes how to interpret the alpha component for a pixel. Must be
+     *                       one of {@link AlphaType} values.
+     * @return {@link MeshSpecification} object for use when creating {@link Mesh}
+     */
+    public static MeshSpecification make(Attribute[] attributes, int vertexStride,
+            Varying[] varyings, String vertexShader, String fragmentShader, ColorSpace colorSpace,
+            @AlphaType int alphaType) {
+        long nativeMeshSpec = nativeMakeWithAlpha(attributes, vertexStride, varyings, vertexShader,
+                fragmentShader, colorSpace.getNativeInstance(), alphaType);
+        if (nativeMeshSpec == 0) {
+            throw new IllegalArgumentException("MeshSpecification construction failed");
+        }
+        return new MeshSpecification(nativeMeshSpec);
+    }
+
+    private MeshSpecification(long meshSpec) {
+        mNativeMeshSpec = meshSpec;
+        MeshSpecificationHolder.MESH_SPECIFICATION_REGISTRY.registerNativeAllocation(
+                this, meshSpec);
+    }
+
+    private static native long nativeGetFinalizer();
+
+    private static native long nativeMake(Attribute[] attributes, int vertexStride,
+            Varying[] varyings, String vertexShader, String fragmentShader);
+
+    private static native long nativeMakeWithCS(Attribute[] attributes, int vertexStride,
+            Varying[] varyings, String vertexShader, String fragmentShader, long colorSpace);
+
+    private static native long nativeMakeWithAlpha(Attribute[] attributes, int vertexStride,
+            Varying[] varyings, String vertexShader, String fragmentShader, long colorSpace,
+            int alphaType);
+}
diff --git a/libs/hwui/jni/MeshSpecification.cpp b/libs/hwui/jni/MeshSpecification.cpp
new file mode 100644
index 0000000..22fa4d3
--- /dev/null
+++ b/libs/hwui/jni/MeshSpecification.cpp
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <SkMesh.h>
+
+#include "GraphicsJNI.h"
+#include "graphics_jni_helpers.h"
+
+namespace android {
+
+using Attribute = SkMeshSpecification::Attribute;
+using Varying = SkMeshSpecification::Varying;
+
+static struct {
+    jclass clazz{};
+    jfieldID type{};
+    jfieldID offset{};
+    jfieldID name{};
+} gAttributeInfo;
+
+static struct {
+    jclass clazz{};
+    jfieldID type{};
+    jfieldID name{};
+} gVaryingInfo;
+
+std::vector<Attribute> extractAttributes(JNIEnv* env, jobjectArray attributes) {
+    int size = env->GetArrayLength(attributes);
+    std::vector<Attribute> attVector;
+    attVector.reserve(size);
+    for (int i = 0; i < size; i++) {
+        jobject attribute = env->GetObjectArrayElement(attributes, i);
+        auto name = (jstring)env->GetObjectField(attribute, gAttributeInfo.name);
+        auto attName = ScopedUtfChars(env, name);
+        Attribute temp{Attribute::Type(env->GetIntField(attribute, gAttributeInfo.type)),
+                       static_cast<size_t>(env->GetIntField(attribute, gAttributeInfo.offset)),
+                       SkString(attName.c_str())};
+        attVector.push_back(std::move(temp));
+    }
+
+    return attVector;
+}
+
+std::vector<Varying> extractVaryings(JNIEnv* env, jobjectArray varyings) {
+    int size = env->GetArrayLength(varyings);
+    std::vector<Varying> varyVector;
+    varyVector.reserve(size);
+    for (int i = 0; i < size; i++) {
+        jobject varying = env->GetObjectArrayElement(varyings, i);
+        auto name = (jstring)env->GetObjectField(varying, gVaryingInfo.name);
+        auto varyName = ScopedUtfChars(env, name);
+        Varying temp{Varying::Type(env->GetIntField(varying, gVaryingInfo.type)),
+                     SkString(varyName.c_str())};
+        varyVector.push_back(std::move(temp));
+    }
+
+    return varyVector;
+}
+
+static jlong Make(JNIEnv* env, jobject thiz, jobjectArray attributeArray, jint vertexStride,
+                  jobjectArray varyingArray, jstring vertexShader, jstring fragmentShader) {
+    auto attributes = extractAttributes(env, attributeArray);
+    auto varyings = extractVaryings(env, varyingArray);
+    auto skVertexShader = ScopedUtfChars(env, vertexShader);
+    auto skFragmentShader = ScopedUtfChars(env, fragmentShader);
+    auto meshSpec = SkMeshSpecification::Make(attributes, vertexStride, varyings,
+                                              SkString(skVertexShader.c_str()),
+                                              SkString(skFragmentShader.c_str()))
+                            .specification;
+    return reinterpret_cast<jlong>(meshSpec.release());
+}
+
+static jlong MakeWithCS(JNIEnv* env, jobject thiz, jobjectArray attributeArray, jint vertexStride,
+                        jobjectArray varyingArray, jstring vertexShader, jstring fragmentShader,
+                        jlong colorSpace) {
+    auto attributes = extractAttributes(env, attributeArray);
+    auto varyings = extractVaryings(env, varyingArray);
+    auto skVertexShader = ScopedUtfChars(env, vertexShader);
+    auto skFragmentShader = ScopedUtfChars(env, fragmentShader);
+    auto meshSpec = SkMeshSpecification::Make(attributes, vertexStride, varyings,
+                                              SkString(skVertexShader.c_str()),
+                                              SkString(skFragmentShader.c_str()),
+                                              GraphicsJNI::getNativeColorSpace(colorSpace))
+                            .specification;
+
+    return reinterpret_cast<jlong>(meshSpec.release());
+}
+
+static jlong MakeWithAlpha(JNIEnv* env, jobject thiz, jobjectArray attributeArray,
+                           jint vertexStride, jobjectArray varyingArray, jstring vertexShader,
+                           jstring fragmentShader, jlong colorSpace, jint alphaType) {
+    auto attributes = extractAttributes(env, attributeArray);
+    auto varyings = extractVaryings(env, varyingArray);
+    auto skVertexShader = ScopedUtfChars(env, vertexShader);
+    auto skFragmentShader = ScopedUtfChars(env, fragmentShader);
+    auto meshSpec = SkMeshSpecification::Make(
+                            attributes, vertexStride, varyings, SkString(skVertexShader.c_str()),
+                            SkString(skFragmentShader.c_str()),
+                            GraphicsJNI::getNativeColorSpace(colorSpace), SkAlphaType(alphaType))
+                            .specification;
+    return reinterpret_cast<jlong>(meshSpec.release());
+}
+
+static void MeshSpecification_safeUnref(SkMeshSpecification* meshSpec) {
+    SkSafeUnref(meshSpec);
+}
+
+static jlong getMeshSpecificationFinalizer() {
+    return static_cast<jlong>(reinterpret_cast<uintptr_t>(&MeshSpecification_safeUnref));
+}
+
+static const JNINativeMethod gMeshSpecificationMethods[] = {
+        {"nativeGetFinalizer", "()J", (void*)getMeshSpecificationFinalizer},
+        {"nativeMake",
+         "([Landroid/graphics/MeshSpecification$Attribute;I[Landroid/graphics/"
+         "MeshSpecification$Varying;"
+         "Ljava/lang/String;Ljava/lang/String;)J",
+         (void*)Make},
+        {"nativeMakeWithCS",
+         "([Landroid/graphics/MeshSpecification$Attribute;I"
+         "[Landroid/graphics/MeshSpecification$Varying;Ljava/lang/String;Ljava/lang/String;J)J",
+         (void*)MakeWithCS},
+        {"nativeMakeWithAlpha",
+         "([Landroid/graphics/MeshSpecification$Attribute;I"
+         "[Landroid/graphics/MeshSpecification$Varying;Ljava/lang/String;Ljava/lang/String;JI)J",
+         (void*)MakeWithAlpha}};
+
+int register_android_graphics_MeshSpecification(JNIEnv* env) {
+    android::RegisterMethodsOrDie(env, "android/graphics/MeshSpecification",
+                                  gMeshSpecificationMethods, NELEM(gMeshSpecificationMethods));
+
+    gAttributeInfo.clazz = env->FindClass("android/graphics/MeshSpecification$Attribute");
+    gAttributeInfo.type = env->GetFieldID(gAttributeInfo.clazz, "mType", "I");
+    gAttributeInfo.offset = env->GetFieldID(gAttributeInfo.clazz, "mOffset", "I");
+    gAttributeInfo.name = env->GetFieldID(gAttributeInfo.clazz, "mName", "Ljava/lang/String;");
+
+    gVaryingInfo.clazz = env->FindClass("android/graphics/MeshSpecification$Varying");
+    gVaryingInfo.type = env->GetFieldID(gVaryingInfo.clazz, "mType", "I");
+    gVaryingInfo.name = env->GetFieldID(gVaryingInfo.clazz, "mName", "Ljava/lang/String;");
+    return 0;
+}
+
+}  // namespace android
\ No newline at end of file