From 4b9a774a4c1c5fbefd056f2d1f617b657b7238b5 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Mon, 12 Oct 2020 22:18:04 +0300
Subject: qcam: viewfinder_gl: Fix fragment shader rebuild when setting format
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When setting a new format, the existing fragment shader is deleted and a
new shader should be created. However, the shader pointer isn't set to
nullptr after deleting it, resulting in the deleter shader being reused.
Fix it by managing shader pointers with std::unique_ptr<> to prevent
similar bugs from happening in the future.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
---
 src/qcam/viewfinder_gl.cpp | 19 ++++++-------------
 src/qcam/viewfinder_gl.h   |  6 ++++--
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/src/qcam/viewfinder_gl.cpp b/src/qcam/viewfinder_gl.cpp
index 0b5c9426..03a576ba 100644
--- a/src/qcam/viewfinder_gl.cpp
+++ b/src/qcam/viewfinder_gl.cpp
@@ -33,7 +33,6 @@ static const QList<libcamera::PixelFormat> supportedFormats{
 
 ViewFinderGL::ViewFinderGL(QWidget *parent)
 	: QOpenGLWidget(parent), buffer_(nullptr), yuvData_(nullptr),
-	  vertexShader_(nullptr), fragmentShader_(nullptr),
 	  vertexBuffer_(QOpenGLBuffer::VertexBuffer),
 	  textureU_(QOpenGLTexture::Target2D),
 	  textureV_(QOpenGLTexture::Target2D),
@@ -58,8 +57,8 @@ int ViewFinderGL::setFormat(const libcamera::PixelFormat &format,
 	if (fragmentShader_) {
 		if (shaderProgram_.isLinked()) {
 			shaderProgram_.release();
-			shaderProgram_.removeShader(fragmentShader_);
-			delete fragmentShader_;
+			shaderProgram_.removeShader(fragmentShader_.get());
+			fragmentShader_.reset();
 		}
 	}
 
@@ -185,7 +184,7 @@ bool ViewFinderGL::selectFormat(const libcamera::PixelFormat &format)
 bool ViewFinderGL::createVertexShader()
 {
 	/* Create Vertex Shader */
-	vertexShader_ = new QOpenGLShader(QOpenGLShader::Vertex, this);
+	vertexShader_ = std::make_unique<QOpenGLShader>(QOpenGLShader::Vertex, this);
 
 	/* Compile the vertex shader */
 	if (!vertexShader_->compileSourceFile(":YUV.vert")) {
@@ -193,7 +192,7 @@ bool ViewFinderGL::createVertexShader()
 		return false;
 	}
 
-	shaderProgram_.addShader(vertexShader_);
+	shaderProgram_.addShader(vertexShader_.get());
 	return true;
 }
 
@@ -207,7 +206,7 @@ bool ViewFinderGL::createFragmentShader()
 	 * program. The #define macros stored in fragmentShaderDefines_, if
 	 * any, are prepended to the source code.
 	 */
-	fragmentShader_ = new QOpenGLShader(QOpenGLShader::Fragment, this);
+	fragmentShader_ = std::make_unique<QOpenGLShader>(QOpenGLShader::Fragment, this);
 
 	QFile file(fragmentShaderFile_);
 	if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
@@ -224,7 +223,7 @@ bool ViewFinderGL::createFragmentShader()
 		return false;
 	}
 
-	shaderProgram_.addShader(fragmentShader_);
+	shaderProgram_.addShader(fragmentShader_.get());
 
 	/* Link shader pipeline */
 	if (!shaderProgram_.link()) {
@@ -287,12 +286,6 @@ void ViewFinderGL::removeShader()
 		shaderProgram_.release();
 		shaderProgram_.removeAllShaders();
 	}
-
-	if (fragmentShader_)
-		delete fragmentShader_;
-
-	if (vertexShader_)
-		delete vertexShader_;
 }
 
 void ViewFinderGL::initializeGL()
diff --git a/src/qcam/viewfinder_gl.h b/src/qcam/viewfinder_gl.h
index ad1e195e..40c04dc5 100644
--- a/src/qcam/viewfinder_gl.h
+++ b/src/qcam/viewfinder_gl.h
@@ -8,6 +8,8 @@
 #ifndef __VIEWFINDER_GL_H__
 #define __VIEWFINDER_GL_H__
 
+#include <memory>
+
 #include <QImage>
 #include <QMutex>
 #include <QOpenGLBuffer>
@@ -67,8 +69,8 @@ private:
 
 	/* Shaders */
 	QOpenGLShaderProgram shaderProgram_;
-	QOpenGLShader *vertexShader_;
-	QOpenGLShader *fragmentShader_;
+	std::unique_ptr<QOpenGLShader> vertexShader_;
+	std::unique_ptr<QOpenGLShader> fragmentShader_;
 	QString fragmentShaderFile_;
 	QStringList fragmentShaderDefines_;
 
-- 
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