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Diffstat (limited to 'libs/gui/GLConsumerUtils.cpp')
| -rw-r--r-- | libs/gui/GLConsumerUtils.cpp | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/libs/gui/GLConsumerUtils.cpp b/libs/gui/GLConsumerUtils.cpp new file mode 100644 index 0000000000..7a06c3d801 --- /dev/null +++ b/libs/gui/GLConsumerUtils.cpp @@ -0,0 +1,125 @@ +/* + * 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. + */ + +#define LOG_TAG "GLConsumerUtils" +//#define LOG_NDEBUG 0 + +#include <gui/GLConsumer.h> +#include <math/mat4.h> +#include <system/window.h> +#include <utils/Log.h> + +namespace android { + +void GLConsumer::computeTransformMatrix(float outTransform[16], + const sp<GraphicBuffer>& buf, const Rect& cropRect, uint32_t transform, + bool filtering) { + // Transform matrices + static const mat4 mtxFlipH( + -1, 0, 0, 0, + 0, 1, 0, 0, + 0, 0, 1, 0, + 1, 0, 0, 1 + ); + static const mat4 mtxFlipV( + 1, 0, 0, 0, + 0, -1, 0, 0, + 0, 0, 1, 0, + 0, 1, 0, 1 + ); + static const mat4 mtxRot90( + 0, 1, 0, 0, + -1, 0, 0, 0, + 0, 0, 1, 0, + 1, 0, 0, 1 + ); + + mat4 xform; + if (transform & NATIVE_WINDOW_TRANSFORM_FLIP_H) { + xform *= mtxFlipH; + } + if (transform & NATIVE_WINDOW_TRANSFORM_FLIP_V) { + xform *= mtxFlipV; + } + if (transform & NATIVE_WINDOW_TRANSFORM_ROT_90) { + xform *= mtxRot90; + } + + if (!cropRect.isEmpty()) { + float tx = 0.0f, ty = 0.0f, sx = 1.0f, sy = 1.0f; + float bufferWidth = buf->getWidth(); + float bufferHeight = buf->getHeight(); + float shrinkAmount = 0.0f; + if (filtering) { + // In order to prevent bilinear sampling beyond the edge of the + // crop rectangle we may need to shrink it by 2 texels in each + // dimension. Normally this would just need to take 1/2 a texel + // off each end, but because the chroma channels of YUV420 images + // are subsampled we may need to shrink the crop region by a whole + // texel on each side. + switch (buf->getPixelFormat()) { + case PIXEL_FORMAT_RGBA_8888: + case PIXEL_FORMAT_RGBX_8888: + case PIXEL_FORMAT_RGBA_FP16: + case PIXEL_FORMAT_RGBA_1010102: + case PIXEL_FORMAT_RGB_888: + case PIXEL_FORMAT_RGB_565: + case PIXEL_FORMAT_BGRA_8888: + // We know there's no subsampling of any channels, so we + // only need to shrink by a half a pixel. + shrinkAmount = 0.5; + break; + + default: + // If we don't recognize the format, we must assume the + // worst case (that we care about), which is YUV420. + shrinkAmount = 1.0; + break; + } + } + + // Only shrink the dimensions that are not the size of the buffer. + if (cropRect.width() < bufferWidth) { + tx = (float(cropRect.left) + shrinkAmount) / bufferWidth; + sx = (float(cropRect.width()) - (2.0f * shrinkAmount)) / + bufferWidth; + } + if (cropRect.height() < bufferHeight) { + ty = (float(bufferHeight - cropRect.bottom) + shrinkAmount) / + bufferHeight; + sy = (float(cropRect.height()) - (2.0f * shrinkAmount)) / + bufferHeight; + } + + mat4 crop( + sx, 0, 0, 0, + 0, sy, 0, 0, + 0, 0, 1, 0, + tx, ty, 0, 1 + ); + xform = crop * xform; + } + + // GLConsumer uses the GL convention where (0, 0) is the bottom-left + // corner and (1, 1) is the top-right corner. Add an additional vertical + // flip after all other transforms to map from GL convention to buffer + // queue memory layout, where (0, 0) is the top-left corner. + xform = mtxFlipV * xform; + + memcpy(outTransform, xform.asArray(), sizeof(xform)); +} + +}; // namespace android |