Mercurial > hg > orthanc-stone
diff Framework/Scene2D/Internals/CairoInfoPanelRenderer.cpp @ 1325:be17fed8c7c5 broker
Added flag in InfoPanelSceneLayer to
apply the scene rotation to the
displayed image.
author | Benjamin Golinvaux <bgo@osimis.io> |
---|---|
date | Tue, 24 Mar 2020 20:34:28 +0100 |
parents | 2d8ab34c8c91 |
children |
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--- a/Framework/Scene2D/Internals/CairoInfoPanelRenderer.cpp Tue Mar 24 16:24:26 2020 +0100 +++ b/Framework/Scene2D/Internals/CairoInfoPanelRenderer.cpp Tue Mar 24 20:34:28 2020 +0100 @@ -34,9 +34,9 @@ texture_.Copy(l.GetTexture(), true); anchor_ = l.GetAnchor(); isLinearInterpolation_ = l.IsLinearInterpolation(); + applySceneRotation_ = l.ShouldApplySceneRotation(); } - void CairoInfoPanelRenderer::Render(const AffineTransform2D& transform, unsigned int canvasWidth, unsigned int canvasHeight) @@ -47,14 +47,71 @@ canvasWidth, canvasHeight); cairo_t* cr = target_.GetCairoContext(); - cairo_save(cr); - cairo_matrix_t t; - cairo_matrix_init_identity(&t); - cairo_matrix_translate(&t, dx, dy); - cairo_transform(cr, &t); + if (applySceneRotation_) + { + // the transformation is as follows: + // - originally, the image is aligned so that its top left corner + // is at 0,0 + // - first, we translate the image by -w/2,-h/2 + // - then we rotate it, so that the next rotation will make the + // image rotate around its center. + // - then, we translate the image by +w/2,+h/2 to put it + // back in place + // - the fourth and last transform is the one that brings the + // image to its desired anchored location. + + int32_t halfWidth = + static_cast<int32_t>(0.5 * texture_.GetWidth()); + + int32_t halfHeight = + static_cast<int32_t>(0.5 * texture_.GetHeight()); + + AffineTransform2D translation1 = + AffineTransform2D::CreateOffset(-halfWidth, -halfHeight); + + const Matrix& sceneTransformM = transform.GetHomogeneousMatrix(); + Matrix r; + Matrix q; + LinearAlgebra::RQDecomposition3x3(r, q, sceneTransformM); + + // first, put the scene rotation in a cairo matrix + cairo_matrix_t m; + cairo_matrix_init( + &m, q(0, 0), q(1, 0), q(0, 1), q(1, 1), q(0, 2), q(1, 2)); + // now let's build the transform piece by piece + // first translation (directly written in `transform`) + cairo_matrix_t transform; + cairo_matrix_init_identity(&transform); + cairo_matrix_translate(&transform, -halfWidth, -halfHeight); + + // then the rotation + cairo_matrix_multiply(&transform, &transform, &m); + + // then the second translation + { + cairo_matrix_t translation2; + cairo_matrix_init_translate(&translation2, halfWidth, halfHeight); + cairo_matrix_multiply(&transform, &transform, &m); + } + + // then the last translation + { + cairo_matrix_t translation3; + cairo_matrix_init_translate(&translation3, dx, dy); + cairo_matrix_multiply(&transform, &transform, &translation3); + } + cairo_transform(cr, &transform); + } + else + { + cairo_matrix_t t; + cairo_matrix_init_identity(&t); + cairo_matrix_translate(&t, dx, dy); + cairo_transform(cr, &t); + } cairo_set_operator(cr, CAIRO_OPERATOR_OVER); cairo_set_source_surface(cr, texture_.GetObject(), 0, 0);