qt: OpenGL ES 3.0 support

src/qt/qt_mainwindow.cpp

@@ -231,6 +231,8 @@ MainWindow::MainWindow(QWidget *parent) :
     ui->actionHardware_Renderer_OpenGL_ES->setVisible(QOpenGLContext::openGLModuleType() == QOpenGLContext::LibGLES);
     if (QOpenGLContext::openGLModuleType() != QOpenGLContext::LibGLES && vid_api == 2) vid_api = 1;
 #endif
+    ui->actionHardware_Renderer_OpenGL->setVisible(QOpenGLContext::openGLModuleType() != QOpenGLContext::LibGLES);
+    if (QOpenGLContext::openGLModuleType() == QOpenGLContext::LibGLES && vid_api == 1) vid_api = 0;
 
     if (QApplication::platformName().contains("eglfs") && vid_api >= 1) {
         fprintf(stderr, "OpenGL renderers are unsupported on EGLFS.\n");

src/qt/qt_opengloptions.cpp

@@ -45,6 +45,25 @@ void main() {\n\
     color = texture(texsampler, tex);\n\
 }\n";
 
+/* Default vertex shader (OpenGL ES 3). */
+static const GLchar *vertex_shader_es3 = "#version 300 es\n\
+in vec2 VertexCoord;\n\
+in vec2 TexCoord;\n\
+out vec2 tex;\n\
+void main(){\n\
+    gl_Position = vec4(VertexCoord, 0.0, 1.0);\n\
+    tex = TexCoord;\n\
+}\n";
+
+/* Default fragment shader (OpenGL ES 3). */
+static const GLchar *fragment_shader_es3 = "#version 300 es\n\
+in vec2 tex;\n\
+uniform sampler2D texsampler;\n\
+out vec4 color;\n\
+void main() {\n\
+    color = texture(texsampler, tex);\n\
+}\n";
+
 OpenGLOptions::OpenGLOptions(QObject *parent, bool loadConfig)
     : QObject(parent)
 {
@@ -149,6 +168,11 @@ OpenGLOptions::addShader(const QString &path)
         shader_text.remove(version);
     }
 
+    if (QOpenGLContext::currentContext() && QOpenGLContext::currentContext()->isOpenGLES())
+    {
+        /* Force #version 300 es (the default of #version 100 es is too old and too limited) */
+        version_line = "#version 300 es";
+    }
     auto shader = new QOpenGLShaderProgram(this);
 
     auto throw_shader_error = [path, shader](const QString &what) {
@@ -175,8 +199,8 @@ void
 OpenGLOptions::addDefaultShader()
 {
     auto shader = new QOpenGLShaderProgram(this);
-    shader->addShaderFromSourceCode(QOpenGLShader::Vertex, vertex_shader);
-    shader->addShaderFromSourceCode(QOpenGLShader::Fragment, fragment_shader);
+    shader->addShaderFromSourceCode(QOpenGLShader::Vertex, QOpenGLContext::currentContext() && QOpenGLContext::currentContext()->isOpenGLES() ? vertex_shader_es3 : vertex_shader);
+    shader->addShaderFromSourceCode(QOpenGLShader::Fragment, QOpenGLContext::currentContext() && QOpenGLContext::currentContext()->isOpenGLES() ? fragment_shader_es3 : fragment_shader);
     shader->link();
     m_shaders << OpenGLShaderPass(shader, QString());
 }

src/qt/qt_opengloptions.hpp

@@ -19,6 +19,7 @@
 
 #include <QList>
 #include <QObject>
+#include <QOpenGLContext>
 #include <QOpenGLShaderProgram>
 
 class OpenGLShaderPass {

src/qt/qt_openglrenderer.cpp

@@ -43,6 +43,7 @@ OpenGLRenderer::OpenGLRenderer(QWidget *parent)
     format.setProfile(QSurfaceFormat::OpenGLContextProfile::CoreProfile);
     format.setMajorVersion(3);
     format.setMinorVersion(0);
+    if (QOpenGLContext::openGLModuleType() == QOpenGLContext::LibGLES) format.setRenderableType(QSurfaceFormat::OpenGLES);
 
     setFormat(format);
 
@@ -389,4 +390,4 @@ OpenGLRenderer::onBlit(int buf_idx, int x, int y, int w, int h)
 
     if (options->renderBehavior() == OpenGLOptions::SyncWithVideo)
         render();
-}
+}

src/qt/qt_openglrenderer.hpp

@@ -23,7 +23,7 @@
 #include <QTimer>
 #include <QWidget>
 #include <QWindow>
-#ifndef Q_OS_MACOS
+#if !defined Q_OS_MACOS && !(QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
 #    include <QtOpenGLExtensions/QOpenGLExtensions>
 #endif