Add GLWidget

include/rack.hpp

@@ -19,6 +19,7 @@
 #include "widgets/ZoomWidget.hpp"
 #include "widgets/SVGWidget.hpp"
 #include "widgets/FramebufferWidget.hpp"
+#include "widgets/GLWidget.hpp"
 
 #include "ui/SequentialLayout.hpp"
 #include "ui/Label.hpp"

include/widgets/FramebufferWidget.hpp

@@ -28,7 +28,7 @@ struct FramebufferWidget : Widget {
 	FramebufferWidget();
 	~FramebufferWidget();
 	void draw(NVGcontext *vg) override;
-	virtual void drawFramebuffer(NVGcontext *vg);
+	virtual void drawFramebuffer();
 	int getImageHandle();
 
 	void onZoom(const event::Zoom &e) override {

include/widgets/GLWidget.hpp

@@ -0,0 +1,14 @@
+#pragma once
+#include "widgets/FramebufferWidget.hpp"
+
+
+namespace rack {
+
+
+struct GLWidget : FramebufferWidget {
+	void step() override;
+	void drawFramebuffer() override;
+};
+
+
+} // namespace rack

src/widgets/FramebufferWidget.cpp

@@ -69,7 +69,7 @@ void FramebufferWidget::draw(NVGcontext *vg) {
 			return;
 
 		nvgluBindFramebuffer(fb);
-		drawFramebuffer(app()->window->fbVg);
+		drawFramebuffer();
 		nvgluBindFramebuffer(NULL);
 	}
 
@@ -101,7 +101,9 @@ void FramebufferWidget::draw(NVGcontext *vg) {
 	nvgRestore(vg);
 }
 
-void FramebufferWidget::drawFramebuffer(NVGcontext *vg) {
+void FramebufferWidget::drawFramebuffer() {
+	NVGcontext *vg = app()->window->fbVg;
+
 	float pixelRatio = fbSize.x / fbBox.size.x;
 	nvgBeginFrame(vg, fbBox.size.x, fbBox.size.y, pixelRatio);
 

src/widgets/GLWidget.cpp

@@ -0,0 +1,34 @@
+#include "widgets/GLWidget.hpp"
+#include "app.hpp"
+
+
+namespace rack {
+
+
+void GLWidget::step() {
+	// Render every frame
+	dirty = true;
+}
+
+
+void GLWidget::drawFramebuffer() {
+	glViewport(0.0, 0.0, fbSize.x, fbSize.y);
+	glClearColor(0.0, 0.0, 0.0, 1.0);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glOrtho(0.0, fbSize.x, 0.0, fbSize.y, -1.0, 1.0);
+
+	glBegin(GL_TRIANGLES);
+	glColor3f(1, 0, 0);
+	glVertex3f(0, 0, 0);
+	glColor3f(0, 1, 0);
+	glVertex3f(fbSize.x, 0, 0);
+	glColor3f(0, 0, 1);
+	glVertex3f(0, fbSize.y, 0);
+	glEnd();
+}
+
+
+} // namespace rack

src/window.cpp

@@ -243,6 +243,11 @@ Window::Window() {
 	// GLEW generates GL error because it calls glGetString(GL_EXTENSIONS), we'll consume it here.
 	glGetError();
 
+	const GLubyte *renderer = glGetString(GL_RENDERER);
+	const GLubyte *version = glGetString(GL_VERSION);
+	INFO("Renderer: %s", renderer);
+	INFO("OpenGL: %s", version);
+
 	glfwSetWindowSizeLimits(win, 800, 600, GLFW_DONT_CARE, GLFW_DONT_CARE);
 
 	// Set up NanoVG