static jlong nativeOpenPageAndGetSize(JNIEnv* env, jclass thiz, jlong documentPtr,
jint pageIndex, jobject outSize) {
FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
FPDF_PAGE page = FPDF_LoadPage(document, pageIndex);
if (!page) {
jniThrowException(env, "java/lang/IllegalStateException",
"cannot load page");
return -1;
}
double width = 0;
double height = 0;
const int result = FPDF_GetPageSizeByIndex(document, pageIndex, &width, &height);
if (!result) {
jniThrowException(env, "java/lang/IllegalStateException",
"cannot get page size");
return -1;
}
env->SetIntField(outSize, gPointClassInfo.x, width);
env->SetIntField(outSize, gPointClassInfo.y, height);
return reinterpret_cast<jlong>(page);
}
static void nativeSetTransformAndClip(JNIEnv* env, jclass thiz, jlong documentPtr, jint pageIndex,
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);
if (!page) {
jniThrowException(env, "java/lang/IllegalStateException",
"cannot open page");
return;
}
double width = 0;
double height = 0;
const int result = FPDF_GetPageSizeByIndex(document, pageIndex, &width, &height);
if (!result) {
jniThrowException(env, "java/lang/IllegalStateException",
"cannot get page size");
return;
}
CFX_AffineMatrix matrix;
SkMatrix* skTransform = reinterpret_cast<SkMatrix*>(transformPtr);
SkScalar transformValues[6];
if (!skTransform->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],
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());
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);
FPDF_ClosePage(page);
}
