post-processing test

src/graphics/PostProcessing.cpp

@@ -0,0 +1,42 @@
+#include "PostProcessing.h"
+#include "Mesh.h"
+#include "Shader.h"
+#include "Texture.h"
+#include "Framebuffer.h"
+
+#include <stdexcept>
+
+PostProcessing::PostProcessing() {
+    // Fullscreen quad mesh bulding
+    float vertices[] {
+        -1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f,
+        -1.0f, -1.0f,  1.0f, 1.0f, 1.0f, -1.0f
+    };
+    vattr attrs[] {{2}, {0}};
+    quadMesh = std::make_unique<Mesh>(vertices, 6, attrs);
+}
+
+PostProcessing::~PostProcessing() {
+}
+
+void PostProcessing::use(GfxContext& context) {
+    const auto& vp = context.getViewport();
+    if (fbo) {
+        fbo->resize(vp.getWidth(), vp.getHeight());
+    } else {
+        fbo = std::make_unique<Framebuffer>(vp.getWidth(), vp.getHeight());
+    }
+    context.setFramebuffer(fbo.get());
+}
+
+void PostProcessing::render(GfxContext& context, Shader* screenShader) {
+    if (fbo == nullptr) {
+        throw std::runtime_error("'use(...)' was never called");
+    }
+
+    const auto& viewport = context.getViewport();
+    screenShader->use();
+    screenShader->uniform2i("u_screenSize", viewport.size());
+    fbo->getTexture()->bind();
+    quadMesh->draw();
+}