gui: OpenGL testing

Author: Lunix-420

src/dmt/gui/display/DisfluxDisplay.h

@@ -31,6 +31,7 @@
 
 #include "dsp/data/FifoAudioBuffer.h"
 #include "gui/display/HelloWorldDisplay.h"
+#include "gui/display/ImpulseResponseDisplay.h"
 #include "gui/display/MultiDisplay.h"
 #include "gui/display/OscilloscopeDisplay.h"
 #include <JuceHeader.h>
@@ -62,6 +63,8 @@ class alignas(64) DisfluxDisplay : public dmt::gui::display::MultiDisplay
           std::vector<std::unique_ptr<AbstractDisplay>> displays;
           displays.push_back(
             std::make_unique<HelloWorldDisplay>());
+          displays.push_back(
+            std::make_unique<ImpulseResponseDisplay>());
           displays.push_back(
             std::make_unique<OscilloscopeDisplay<float>>(_fifoBuffer,
                                                          _apvts,

src/dmt/gui/display/ImpulseResponseDisplay.h

@@ -0,0 +1,150 @@
+#pragma once
+
+//==============================================================================
+
+#include "gui/display/AbstractDisplay.h"
+#include "gui/widget/Label.h"
+// #include "utility/Settings.h"
+#include "utility/Fonts.h"
+#include <JuceHeader.h>
+
+//==============================================================================
+
+namespace dmt {
+namespace gui {
+namespace display {
+
+//==============================================================================
+
+/**
+ * @class ImpulseResponseDisplay
+ * @brief Specialized display component inheriting from
+ * AbstractDisplay.
+ */
+class ImpulseResponseDisplay
+  : public dmt::gui::display::AbstractDisplay
+  , public juce::OpenGLRenderer
+{
+  using Label = dmt::gui::widget::Label;
+  using Settings = dmt::Settings;
+  using Fonts = dmt::utility::Fonts;
+  using Colour = juce::Colour;
+
+public:
+  explicit ImpulseResponseDisplay()
+    : AbstractDisplay()
+    , label("Impulse Response", fonts.bold, rawFontSize, juce::Colours::white)
+  {
+    // addAndMakeVisible(label);
+    openGLContext.setRenderer(this);
+    openGLContext.attachTo(*this);
+    openGLContext.setContinuousRepainting(true);
+    openGLContext.setComponentPaintingEnabled(true);
+  }
+
+  ~ImpulseResponseDisplay() override { openGLContext.detach(); }
+
+  void newOpenGLContextCreated() override
+  {
+    shaderProgram.reset(new juce::OpenGLShaderProgram(openGLContext));
+
+    if (!shaderProgram->addVertexShader(vertexShaderSource) ||
+        !shaderProgram->addFragmentShader(fragmentShaderSource) ||
+        !shaderProgram->link()) {
+      jassertfalse; // shader compile/link failed
+    }
+
+    positionAttributeID = openGLContext.extensions.glGetAttribLocation(
+      shaderProgram->getProgramID(), "aPos");
+    jassert(positionAttributeID >= 0);
+    createTriangle();
+  }
+
+  void renderOpenGL() override
+  {
+    juce::OpenGLHelpers::clear(juce::Colours::black);
+
+    juce::OpenGLContext::getCurrentContext()->extensions.glUseProgram(
+      shaderProgram->getProgramID());
+
+    auto& gl = openGLContext.extensions;
+
+    gl.glEnableVertexAttribArray(positionAttributeID);
+
+    gl.glBindBuffer(juce::gl::GL_ARRAY_BUFFER, vbo);
+
+    gl.glVertexAttribPointer(positionAttributeID,
+                             2,
+                             juce::gl::GL_FLOAT,
+                             juce::gl::GL_FALSE,
+                             sizeof(float) * 2,
+                             nullptr);
+
+    juce::gl::glDrawArrays(juce::gl::GL_TRIANGLES, 0, 3);
+
+    gl.glDisableVertexAttribArray(positionAttributeID);
+  }
+
+  void resized() noexcept override { label.setBounds(getLocalBounds()); }
+
+  void paint(juce::Graphics& _g) noexcept override
+  {
+    if (Settings::debugBounds) {
+      _g.setColour(juce::Colours::cyan);
+      _g.drawRect(getLocalBounds(), 1);
+    }
+    _g.fillAll(juce::Colours::cyan);
+  }
+
+  void openGLContextClosing() override
+  {
+    auto& gl = openGLContext.extensions;
+    shaderProgram.reset();
+    gl.glDeleteBuffers(1, &vbo);
+  }
+
+private:
+  juce::OpenGLContext openGLContext;
+  std::unique_ptr<juce::OpenGLShaderProgram> shaderProgram;
+  int positionAttributeID = -1;
+  GLuint vbo = 0;
+  void createTriangle()
+  {
+    float vertices[] = { -0.5f, -0.5f, 0.5f, -0.5f, 0.0f, 0.5f };
+    auto& gl = openGLContext.extensions;
+    gl.glGenBuffers(1, &vbo);
+    gl.glBindBuffer(juce::gl::GL_ARRAY_BUFFER, vbo);
+    gl.glBufferData(juce::gl::GL_ARRAY_BUFFER,
+                    sizeof(vertices),
+                    vertices,
+                    juce::gl::GL_STATIC_DRAW);
+  }
+  const char* vertexShaderSource = R"(
+        #version 330 core
+        layout(location = 0) in vec2 aPos;
+
+        void main()
+        {
+            gl_Position = vec4(aPos, 0.0, 1.0);
+        }
+    )";
+
+  const char* fragmentShaderSource = R"(
+        #version 330 core
+        out vec4 FragColor;
+
+        void main()
+        {
+            FragColor = vec4(1.0, 0.6, 0.2, 1.0);
+        }
+    )";
+
+  Label label;
+  Fonts fonts;
+  float rawFontSize = 24.0f;
+
+  JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(ImpulseResponseDisplay)
+};
+} // namespace display
+} // namespace gui
+} // namespace dmt

src/dmt/gui/widget/SimpleButton.h

@@ -100,7 +100,7 @@ class SimpleButton
       g.drawRect(outerBounds, borderThickness);
     }
 
-    g.fillAll(juce::Colours::red);
+    // g.fillAll(juce::Colours::red);
   }
 
   //==============================================================================

src/dmt/shaders/basic_frag.glsl

@@ -0,0 +1,7 @@
+#version 330 core
+out vec4 FragColor;
+
+void main()
+{
+    FragColor = vec4(1.0, 0.6, 0.2, 1.0);
+}

src/dmt/shaders/basic_vertex.glsl

@@ -0,0 +1,8 @@
+#version 330 core
+
+layout(location = 0) in vec2 aPos;
+
+void main()
+{
+    gl_Position = vec4(aPos, 0.0, 1.0);
+}