From 9db6ce0ba499eba53db236558d783a4ff7aa3896 Mon Sep 17 00:00:00 2001
From: Show Liu <show.liu@linaro.org>
Date: Fri, 11 Sep 2020 16:55:13 +0800
Subject: qcam: Add ViewFinderGL class to accelerate the format conversion

The viewfinderGL accelerates the format conversion by using OpenGL ES
shader.

The minimum Qt version is bumped to v5.4, as QOpenGLWidget wasn't
available before that.

Signed-off-by: Show Liu <show.liu@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/qcam/viewfinder_gl.h | 96 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 src/qcam/viewfinder_gl.h

(limited to 'src/qcam/viewfinder_gl.h')

diff --git a/src/qcam/viewfinder_gl.h b/src/qcam/viewfinder_gl.h
new file mode 100644
index 00000000..69502b7a
--- /dev/null
+++ b/src/qcam/viewfinder_gl.h
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Linaro
+ *
+ * viewfinder_GL.h - OpenGL Viewfinder for rendering by OpenGL shader
+ *
+ */
+#ifndef __VIEWFINDER_GL_H__
+#define __VIEWFINDER_GL_H__
+
+#include <QImage>
+#include <QMutex>
+#include <QOpenGLBuffer>
+#include <QOpenGLFunctions>
+#include <QOpenGLShader>
+#include <QOpenGLShaderProgram>
+#include <QOpenGLTexture>
+#include <QOpenGLWidget>
+#include <QSize>
+
+#include <libcamera/buffer.h>
+#include <libcamera/formats.h>
+
+#include "viewfinder.h"
+
+class ViewFinderGL : public QOpenGLWidget,
+		     public ViewFinder,
+		     protected QOpenGLFunctions
+{
+	Q_OBJECT
+
+public:
+	ViewFinderGL(QWidget *parent = nullptr);
+	~ViewFinderGL();
+
+	const QList<libcamera::PixelFormat> &nativeFormats() const override;
+
+	int setFormat(const libcamera::PixelFormat &format, const QSize &size) override;
+	void render(libcamera::FrameBuffer *buffer, MappedBuffer *map) override;
+	void stop() override;
+
+	QImage getCurrentImage() override;
+
+Q_SIGNALS:
+	void renderComplete(libcamera::FrameBuffer *buffer);
+
+protected:
+	void initializeGL() override;
+	void paintGL() override;
+	void resizeGL(int w, int h) override;
+	QSize sizeHint() const override;
+
+private:
+	bool selectFormat(const libcamera::PixelFormat &format);
+
+	void configureTexture(unsigned int id);
+	bool createFragmentShader();
+	bool createVertexShader();
+	void removeShader();
+	void doRender();
+
+	/* Captured image size, format and buffer */
+	libcamera::FrameBuffer *buffer_;
+	libcamera::PixelFormat format_;
+	QSize size_;
+	unsigned char *yuvData_;
+
+	/* OpenGL components for rendering */
+	QOpenGLShader *fragmentShader_;
+	QOpenGLShader *vertexShader_;
+	QOpenGLShaderProgram shaderProgram_;
+
+	/* Vertex buffer */
+	QOpenGLBuffer vertexBuffer_;
+
+	/* Fragment and Vertex shader file name */
+	QString fragmentShaderSrc_;
+	QString vertexShaderSrc_;
+
+	/* YUV texture planars and parameters */
+	GLuint id_u_;
+	GLuint id_v_;
+	GLuint id_y_;
+	GLuint textureUniformU_;
+	GLuint textureUniformV_;
+	GLuint textureUniformY_;
+	QOpenGLTexture textureU_;
+	QOpenGLTexture textureV_;
+	QOpenGLTexture textureY_;
+	unsigned int horzSubSample_;
+	unsigned int vertSubSample_;
+
+	QMutex mutex_; /* Prevent concurrent access to image_ */
+};
+
+#endif /* __VIEWFINDER_GL_H__ */
-- 
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