Qt: load unpacked shaders, warn on shader load error

src/platform/qt/Display.h

@@ -81,7 +81,7 @@ public slots:
 	virtual void filter(bool filter);
 	virtual void swapInterval(int interval) = 0;
 	virtual void framePosted() = 0;
-	virtual void setShaders(struct VDir*) = 0;
+	virtual bool setShaders(struct VDir*) = 0;
 	virtual void clearShaders() = 0;
 	virtual void resizeContext() = 0;
 

src/platform/qt/DisplayGL.cpp

@@ -462,8 +462,10 @@ void DisplayGL::framePosted() {
 	QMetaObject::invokeMethod(m_painter.get(), "draw");
 }
 
-void DisplayGL::setShaders(struct VDir* shaders) {
-	QMetaObject::invokeMethod(m_painter.get(), "setShaders", Qt::BlockingQueuedConnection, Q_ARG(struct VDir*, shaders));
+bool DisplayGL::setShaders(struct VDir* shaders) {
+	bool success = false;
+	QMetaObject::invokeMethod(m_painter.get(), "setShaders", Qt::BlockingQueuedConnection, Q_RETURN_ARG(bool, success), Q_ARG(struct VDir*, shaders));
+	return success;
 }
 
 void DisplayGL::clearShaders() {
@@ -996,10 +998,11 @@ void PainterGL::interrupt() {
 	m_interrupter.interrupt(m_context);
 }
 
-void PainterGL::setShaders(struct VDir* dir) {
+bool PainterGL::setShaders(struct VDir* dir) {
 	if (!supportsShaders()) {
-		return;
+		return false;
 	}
+	bool success = false;
 #if defined(BUILD_GLES2) || defined(BUILD_GLES3)
 	if (!m_started) {
 		makeCurrent();
@@ -1009,7 +1012,9 @@ void PainterGL::setShaders(struct VDir* dir) {
 		mGLES2ShaderDetach(reinterpret_cast<mGLES2Context*>(m_backend));
 		mGLES2ShaderFree(&m_shader);
 	}
-	if (mGLES2ShaderLoad(&m_shader, dir)) {
+
+	success = mGLES2ShaderLoad(&m_shader, dir);
+	if (success) {
 		mGLES2ShaderAttach(reinterpret_cast<mGLES2Context*>(m_backend), static_cast<mGLES2Shader*>(m_shader.passes), m_shader.nPasses);
 	}
 
@@ -1017,6 +1022,7 @@ void PainterGL::setShaders(struct VDir* dir) {
 		m_gl->doneCurrent();
 	}
 #endif
+	return success;
 }
 
 void PainterGL::clearShaders() {

src/platform/qt/DisplayGL.h

@@ -113,7 +113,7 @@ public slots:
 	void filter(bool filter) override;
 	void swapInterval(int interval) override;
 	void framePosted() override;
-	void setShaders(struct VDir*) override;
+	bool setShaders(struct VDir*) override;
 	void clearShaders() override;
 	void resizeContext() override;
 	void setVideoScale(int scale) override;
@@ -184,7 +184,7 @@ public slots:
 	void resizeContext();
 	void setBackgroundImage(const QImage&);
 
-	void setShaders(struct VDir*);
+	bool setShaders(struct VDir*);
 	void clearShaders();
 	VideoShader* shaders();
 	QSize contentSize() const;

src/platform/qt/DisplayQt.h

@@ -41,7 +41,7 @@ public slots:
 	void swapInterval(int) override {};
 	void filter(bool filter) override;
 	void framePosted() override;
-	void setShaders(struct VDir*) override {}
+	bool setShaders(struct VDir*) override { return false; }
 	void clearShaders() override {}
 	void resizeContext() override;
 	void setBackgroundImage(const QImage&) override;

src/platform/qt/ShaderSelector.cpp

@@ -16,6 +16,7 @@
 #include <QFileDialog>
 #include <QFormLayout>
 #include <QGridLayout>
+#include <QMessageBox>
 #include <QSpinBox>
 
 #include <mgba/core/version.h>
@@ -50,7 +51,7 @@ ShaderSelector::~ShaderSelector() {
 }
 
 void ShaderSelector::saveSettings() {
-	QString oldPath = config->getOption("shader");
+	QString oldPath = m_config->getOption("shader");
 	if (oldPath != m_shaderPath) {
 		if (m_shaderPath.isEmpty()) {
 			clearShader(true);
@@ -88,7 +89,8 @@ void ShaderSelector::selectShader() {
 #if !defined(USE_LIBZIP) && !defined(USE_MINIZIP)
 	QString name = GBAApp::app()->getOpenDirectoryName(this, tr("Load shader"), path.absolutePath());
 #else
-	QString name = GBAApp::app()->getOpenFileName(this, tr("Load shader"), "mGBA Shaders (*.shader)", path.absolutePath());
+	QString filters = QStringLiteral("%1 (*.shader manifest.ini)").arg(tr("mGBA Shaders"));
+	QString name = GBAApp::app()->getOpenFileName(this, tr("Load shader"), filters, path.absolutePath());
 #endif
 	if (!name.isNull()) {
 		loadShader(name);
@@ -97,18 +99,28 @@ void ShaderSelector::selectShader() {
 }
 
 void ShaderSelector::loadShader(const QString& path, bool saveToSettings) {
-	VDir* shader = VFileDevice::openDir(path);
-	if (!shader) {
-		shader = VFileDevice::openArchive(path);
+	static const QString manifestIni = "/manifest.ini";
+	QString shaderPath = path;
+	if (shaderPath.endsWith(manifestIni)) {
+		shaderPath.chop(manifestIni.length());
 	}
+	VDir* shader = VFileDevice::openDir(shaderPath);
 	if (!shader) {
-		return;
+		shader = VFileDevice::openArchive(shaderPath);
 	}
-	m_display->setShaders(shader);
-	shader->close(shader);
-	m_shaderPath = path;
-	if (saveToSettings) {
-		m_config->setOption("shader", path);
+	bool error = !shader || !m_display->setShaders(shader);
+	if (!error) {
+		if (saveToSettings) {
+			m_config->setOption("shader", shaderPath);
+		}
+		m_shaderPath = shaderPath;
+		refreshShaders();
+	}
+	if (shader) {
+		shader->close(shader);
+	}
+	if (error) {
+		QMessageBox::warning(this, tr("Error loading shader"), tr("The shader \"%1\" could not be loaded successfully.").arg(shaderPath));
 	}
 }