1 files changed, 118 insertions, 0 deletions
diff --git a/tests/java_api/ImageProcessing2/src/com/android/rs/image/threshold.rscript b/tests/java_api/ImageProcessing2/src/com/android/rs/image/threshold.rscript
new file mode 100644
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+++ b/tests/java_api/ImageProcessing2/src/com/android/rs/image/threshold.rscript
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2013 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 "ip.rsh"
+#pragma rs_fp_relaxed
+
+int height;
+int width;
+static int radius;
+
+rs_allocation InPixel;
+rs_allocation ScratchPixel1;
+rs_allocation ScratchPixel2;
+
+const int MAX_RADIUS = 25;
+
+// Store our coefficients here
+static float gaussian[MAX_RADIUS * 2 + 1];
+
+void setRadius(int rad) {
+    radius = rad;
+    // Compute gaussian weights for the blur
+    // e is the euler's number
+    float e = 2.718281828459045f;
+    float pi = 3.1415926535897932f;
+    // g(x) = ( 1 / sqrt( 2 * pi ) * sigma) * e ^ ( -x^2 / 2 * sigma^2 )
+    // x is of the form [-radius .. 0 .. radius]
+    // and sigma varies with radius.
+    // Based on some experimental radius values and sigma's
+    // we approximately fit sigma = f(radius) as
+    // sigma = radius * 0.4  + 0.6
+    // The larger the radius gets, the more our gaussian blur
+    // will resemble a box blur since with large sigma
+    // the gaussian curve begins to lose its shape
+    float sigma = 0.4f * (float)radius + 0.6f;
+
+    // Now compute the coefficints
+    // We will store some redundant values to save some math during
+    // the blur calculations
+    // precompute some values
+    float coeff1 = 1.0f / (sqrt( 2.0f * pi ) * sigma);
+    float coeff2 = - 1.0f / (2.0f * sigma * sigma);
+
+    float normalizeFactor = 0.0f;
+    float floatR = 0.0f;
+    for (int r = -radius; r <= radius; r ++) {
+        floatR = (float)r;
+        gaussian[r + radius] = coeff1 * pow(e, floatR * floatR * coeff2);
+        normalizeFactor += gaussian[r + radius];
+    }
+
+    //Now we need to normalize the weights because all our coefficients need to add up to one
+    normalizeFactor = 1.0f / normalizeFactor;
+    for (int r = -radius; r <= radius; r ++) {
+        floatR = (float)r;
+        gaussian[r + radius] *= normalizeFactor;
+    }
+}
+
+float4 RS_KERNEL copyIn(uchar4 in) {
+    return convert_float4(in);
+}
+
+uchar4 RS_KERNEL vert(uint32_t x, uint32_t y) {
+    float3 blurredPixel = 0;
+    int gi = 0;
+    uchar4 out;
+    if ((y > radius) && (y < (height - radius))) {
+        for (int r = -radius; r <= radius; r ++) {
+            float4 i = rsGetElementAt_float4(ScratchPixel2, x, y + r);
+            blurredPixel += i.xyz * gaussian[gi++];
+        }
+    } else {
+        for (int r = -radius; r <= radius; r ++) {
+            int validH = rsClamp((int)y + r, (int)0, (int)(height - 1));
+            float4 i = rsGetElementAt_float4(ScratchPixel2, x, validH);
+            blurredPixel += i.xyz * gaussian[gi++];
+        }
+    }
+
+    out.xyz = convert_uchar3(clamp(blurredPixel, 0.f, 255.f));
+    out.w = 0xff;
+    return out;
+}
+
+float4 RS_KERNEL horz(uint32_t x, uint32_t y) {
+    float4 blurredPixel = 0;
+    int gi = 0;
+    if ((x > radius) && (x < (width - radius))) {
+        for (int r = -radius; r <= radius; r ++) {
+            float4 i = rsGetElementAt_float4(ScratchPixel1, x + r, y);
+            blurredPixel += i * gaussian[gi++];
+        }
+    } else {
+        for (int r = -radius; r <= radius; r ++) {
+            // Stepping left and right away from the pixel
+            int validX = rsClamp((int)x + r, (int)0, (int)(width - 1));
+            float4 i = rsGetElementAt_float4(ScratchPixel1, validX, y);
+            blurredPixel += i * gaussian[gi++];
+        }
+    }
+
+    return blurredPixel;
+}
+