Add support for drawLines(), with anti-aliasing
Change-Id: I16c0593c5671490909dec13a85df601e1428a1a6
diff --git a/libs/hwui/Line.h b/libs/hwui/Line.h
new file mode 100644
index 0000000..48e18eb
--- /dev/null
+++ b/libs/hwui/Line.h
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#ifndef ANDROID_UI_LINE_H
+#define ANDROID_UI_LINE_H
+
+#include <GLES2/gl2.h>
+
+#include <cmath>
+
+#include <sys/types.h>
+
+#include "Patch.h"
+
+namespace android {
+namespace uirenderer {
+
+///////////////////////////////////////////////////////////////////////////////
+// Globals
+///////////////////////////////////////////////////////////////////////////////
+
+// Alpha8 texture used to perform texture anti-aliasing
+static const uint8_t gLineTexture[] = {
+ 0, 0, 0, 0, 0,
+ 0, 255, 255, 255, 0,
+ 0, 255, 255, 255, 0,
+ 0, 255, 255, 255, 0,
+ 0, 0, 0, 0, 0
+};
+static const GLsizei gLineTextureWidth = 5;
+static const GLsizei gLineTextureHeight = 5;
+static const float gLineAABias = 1.0f;
+
+///////////////////////////////////////////////////////////////////////////////
+// Line
+///////////////////////////////////////////////////////////////////////////////
+
+class Line {
+public:
+ Line(): mXDivsCount(2), mYDivsCount(2) {
+ mPatch = new Patch(mXDivsCount, mYDivsCount);
+ mXDivs = new int32_t[mXDivsCount];
+ mYDivs = new int32_t[mYDivsCount];
+
+ mXDivs[0] = mYDivs[0] = 2;
+ mXDivs[1] = mYDivs[1] = 3;
+
+ glGenTextures(1, &mTexture);
+ glBindTexture(GL_TEXTURE_2D, mTexture);
+
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+ glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, gLineTextureWidth, gLineTextureHeight, 0,
+ GL_ALPHA, GL_UNSIGNED_BYTE, gLineTexture);
+ }
+
+ ~Line() {
+ delete mPatch;
+ delete mXDivs;
+ delete mYDivs;
+
+ glDeleteTextures(1, &mTexture);
+ }
+
+ void update(float x1, float y1, float x2, float y2, float lineWidth, float& tx, float& ty) {
+ const float length = sqrtf((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));
+ const float half = lineWidth * 0.5f;
+
+ mPatch->updateVertices(gLineTextureWidth, gLineTextureHeight,
+ -gLineAABias, -half - gLineAABias, length + gLineAABias, half + gLineAABias,
+ mXDivs, mYDivs, mXDivsCount, mYDivsCount);
+
+ tx = -gLineAABias;
+ ty = -half - gLineAABias;
+ }
+
+ inline GLvoid* getVertices() const {
+ return &mPatch->vertices[0].position[0];
+ }
+
+ inline GLvoid* getTexCoords() const {
+ return &mPatch->vertices[0].texture[0];
+ }
+
+ inline GLsizei getElementsCount() const {
+ return mPatch->verticesCount;
+ }
+
+ inline GLuint getTexture() const {
+ return mTexture;
+ }
+
+private:
+ uint32_t mXDivsCount;
+ uint32_t mYDivsCount;
+
+ int32_t* mXDivs;
+ int32_t* mYDivs;
+
+ Patch* mPatch;
+
+ GLuint mTexture;
+}; // class Line
+
+}; // namespace uirenderer
+}; // namespace android
+
+#endif // ANDROID_UI_LINE_H