Use SkMatrix to compute pdf transformation. (61a53074) · Commits · e / os / android_frameworks_base

core/jni/android/graphics/pdf/PdfEditor.cpp

+18 −17

Original line number	Diff line number	Diff line
		@@ -22,7 +22,6 @@
		#include "fpdfview.h"
		#include "fpdf_edit.h"
		#include "fpdf_save.h"
		#include "fsdk_rendercontext.h"
		#include "fpdf_transformpage.h"
		#pragma GCC diagnostic pop

		@@ -176,7 +175,7 @@ static void nativeSetTransformAndClip(JNIEnv* env, jclass thiz, jlong documentPt
		jlong transformPtr, jint clipLeft, jint clipTop, jint clipRight, jint clipBottom) {
		FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);

		CPDF_Page* page = (CPDF_Page*) FPDF_LoadPage(document, pageIndex);
		FPDF_PAGE* page = (FPDF_PAGE*) FPDF_LoadPage(document, pageIndex);
		if (!page) {
		jniThrowException(env, "java/lang/IllegalStateException",
		"cannot open page");
		@@ -193,30 +192,32 @@ static void nativeSetTransformAndClip(JNIEnv* env, jclass thiz, jlong documentPt
		return;
		}

		CFX_Matrix matrix;

		SkMatrix* skTransform = reinterpret_cast<SkMatrix*>(transformPtr);
		// PDF's coordinate system origin is left-bottom while in graphics it
		// is the top-left. So, translate the PDF coordinates to ours.
		SkMatrix reflectOnX = SkMatrix::MakeScale(1, -1);
		SkMatrix moveUp = SkMatrix::MakeTrans(0, FPDF_GetPageHeight(page));
		SkMatrix coordinateChange = SkMatrix::Concat(moveUp, reflectOnX);

		// Apply the transformation what was created in our coordinates.
		SkMatrix matrix = SkMatrix::Concat(reinterpret_cast<SkMatrix>(transformPtr),
		coordinateChange);

		// Translate the result back to PDF coordinates.
		matrix.setConcat(coordinateChange, matrix);

		SkScalar transformValues[6];
		if (!skTransform->asAffine(transformValues)) {
		if (!matrix.asAffine(transformValues)) {
		jniThrowException(env, "java/lang/IllegalArgumentException",
		"transform matrix has perspective. Only affine matrices are allowed.");
		return;
		}

		// PDF's coordinate system origin is left-bottom while in graphics it
		// is the top-left. So, translate the PDF coordinates to ours.
		matrix.Set(1, 0, 0, -1, 0, page->GetPageHeight());

		// Apply the transformation what was created in our coordinates.
		matrix.Concat(transformValues[SkMatrix::kAScaleX], transformValues[SkMatrix::kASkewY],
		FS_MATRIX transform = {transformValues[SkMatrix::kAScaleX], transformValues[SkMatrix::kASkewY],
		transformValues[SkMatrix::kASkewX], transformValues[SkMatrix::kAScaleY],
		transformValues[SkMatrix::kATransX], transformValues[SkMatrix::kATransY]);

		// Translate the result back to PDF coordinates.
		matrix.Concat(1, 0, 0, -1, 0, page->GetPageHeight());
		transformValues[SkMatrix::kATransX],
		transformValues[SkMatrix::kATransY]};

		FS_MATRIX transform = {matrix.a, matrix.b, matrix.c, matrix.d, matrix.e, matrix.f};
		FS_RECTF clip = {(float) clipLeft, (float) clipTop, (float) clipRight, (float) clipBottom};

		FPDFPage_TransFormWithClip(page, &transform, &clip);

core/jni/android/graphics/pdf/PdfRenderer.cpp

+10 −6

Original line number	Diff line number	Diff line
		@@ -212,19 +212,23 @@ static void renderPageBitmap(FPDF_BITMAP bitmap, FPDF_PAGE page, int destLeft, i
		} else {
		// PDF's coordinate system origin is left-bottom while
		// in graphics it is the top-left, so remap the origin.
		matrix.Set(1, 0, 0, -1, 0, pPage->GetPageHeight());
		SkMatrix reflectOnX = SkMatrix::MakeScale(1, -1);
		SkMatrix moveUp = SkMatrix::MakeTrans(0, FPDF_GetPageHeight(page));
		SkMatrix m = SkMatrix::Concat(moveUp, reflectOnX);

		// Concatenate transformation and origin transformation
		m.setConcat(*transform, m);

		SkScalar transformValues[6];
		if (transform->asAffine(transformValues)) {
		matrix.Concat(transformValues[SkMatrix::kAScaleX], transformValues[SkMatrix::kASkewY],
		transformValues[SkMatrix::kASkewX], transformValues[SkMatrix::kAScaleY],
		transformValues[SkMatrix::kATransX], transformValues[SkMatrix::kATransY]);
		} else {
		if (!m.asAffine(transformValues)) {
		// Already checked for a return value of false in the caller, so this should never
		// happen.
		ALOGE("Error rendering page!");
		}

		matrix = {transformValues[SkMatrix::kAScaleX], transformValues[SkMatrix::kASkewY],
		transformValues[SkMatrix::kASkewX], transformValues[SkMatrix::kAScaleY],
		transformValues[SkMatrix::kATransX], transformValues[SkMatrix::kATransY]};
		}
		pageContext->AppendObjectList(pPage, &matrix);