Apply graphic effects in TargetPainter

Author: adazem009

src/targetpainter.cpp

@@ -8,6 +8,7 @@
 #include "irenderedtarget.h"
 #include "spritemodel.h"
 #include "bitmapskin.h"
+#include "shadermanager.h"
 
 using namespace scratchcpprender;
 
@@ -59,15 +60,57 @@ void TargetPainter::paint(QNanoPainter *painter)
         return;
     }
 
-    // Blit the FBO to the Qt Quick FBO
-    glF.glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
-    glF.glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFbo->handle());
-    glF.glBlitFramebuffer(0, 0, texture.width(), texture.height(), 0, 0, targetFbo->width(), targetFbo->height(), GL_COLOR_BUFFER_BIT, GL_NEAREST);
+    // Get the shader program for the current set of effects
+    ShaderManager *shaderManager = ShaderManager::instance();
+
+    const auto &effects = m_target->graphicEffects();
+    QOpenGLShaderProgram *shaderProgram = shaderManager->getShaderProgram(effects);
+    Q_ASSERT(shaderProgram);
+    Q_ASSERT(shaderProgram->isLinked());
+
+    // Set up vertex data and buffers for a quad
+    float vertices[] = {
+        -1.0f, -1.0f, 0.0f, 0.0f, 1.0f, -1.0f, 1.0f, 0.0f, -1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    };
+
+    GLuint VBO, VAO;
+    glF.glGenVertexArrays(1, &VAO);
+    glF.glGenBuffers(1, &VBO);
+
+    glF.glBindVertexArray(VAO);
+
+    glF.glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glF.glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    // Position attribute
+    glF.glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void *)0);
+    glF.glEnableVertexAttribArray(0);
+
+    // Texture coordinate attribute
+    glF.glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void *)(2 * sizeof(float)));
+    glF.glEnableVertexAttribArray(1);
+
+    // Render to the target framebuffer
     glF.glBindFramebuffer(GL_FRAMEBUFFER, targetFbo->handle());
+    shaderProgram->bind();
+    glF.glBindVertexArray(VAO);
+    glF.glActiveTexture(GL_TEXTURE0);
+    glF.glBindTexture(GL_TEXTURE_2D, texture.handle());
+    shaderManager->setUniforms(shaderProgram, 0, effects); // set texture and effect uniforms
+    glF.glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+    // Process the resulting texture
+    // NOTE: This must happen now, not later, because the alpha channel can be used here
+    m_target->updateHullPoints(targetFbo);
 
+    // Cleanup
+    shaderProgram->release();
+    glF.glBindFramebuffer(GL_FRAMEBUFFER, 0);
     glF.glDeleteFramebuffers(1, &fbo);
 
-    m_target->updateHullPoints(targetFbo);
+    // Delete vertex array and buffer
+    glF.glDeleteVertexArrays(1, &VAO);
+    glF.glDeleteBuffers(1, &VBO);
 }
 
 void TargetPainter::synchronize(QNanoQuickItem *item)

test/color_effects.png

@@ -11,31 +11,29 @@ using ::testing::ReturnRef;
 class TargetPainterTest : public testing::Test
 {
     public:
-        void createContextAndSurface(QOpenGLContext *context, QOffscreenSurface *surface)
+        void SetUp() override
         {
-            QSurfaceFormat surfaceFormat;
-            surfaceFormat.setMajorVersion(4);
-            surfaceFormat.setMinorVersion(3);
+            m_context.create();
+            ASSERT_TRUE(m_context.isValid());
 
-            context->setFormat(surfaceFormat);
-            context->create();
-            ASSERT_TRUE(context->isValid());
-
-            surface->setFormat(surfaceFormat);
-            surface->create();
-            ASSERT_TRUE(surface->isValid());
+            m_surface.setFormat(m_context.format());
+            m_surface.create();
+            Q_ASSERT(m_surface.isValid());
+            m_context.makeCurrent(&m_surface);
+        }
 
-            context->makeCurrent(surface);
-            ASSERT_EQ(QOpenGLContext::currentContext(), context);
+        void TearDown() override
+        {
+            ASSERT_EQ(m_context.surface(), &m_surface);
+            m_context.doneCurrent();
         }
+
+        QOpenGLContext m_context;
+        QOffscreenSurface m_surface;
 };
 
 TEST_F(TargetPainterTest, Paint)
 {
-    QOpenGLContext context;
-    QOffscreenSurface surface;
-    createContextAndSurface(&context, &surface);
-
     QOpenGLFramebufferObjectFormat format;
     format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
 
@@ -48,8 +46,10 @@ TEST_F(TargetPainterTest, Paint)
     // Paint reference
     refPainter.setAntialias(0);
     refPainter.setStrokeStyle(QNanoColor(255, 0, 0, 128));
-    refPainter.ellipse(refFbo.width() / 2, refFbo.height() / 2, refFbo.width() / 2, refFbo.height() / 2);
+    refPainter.setFillStyle(QNanoColor(0, 0, 100, 150));
+    refPainter.rect(5, 5, refFbo.width() - 10, refFbo.height() - 10);
     refPainter.stroke();
+    refPainter.fill();
     refPainter.endFrame();
 
     // Begin painting
@@ -76,17 +76,38 @@ TEST_F(TargetPainterTest, Paint)
 
     // Paint
     Texture texture(refFbo.texture(), refFbo.size());
+    std::unordered_map<ShaderManager::Effect, double> effects;
     EXPECT_CALL(target, texture()).WillOnce(Return(texture));
+    EXPECT_CALL(target, graphicEffects()).WillOnce(ReturnRef(effects));
     EXPECT_CALL(target, updateHullPoints(&fbo));
     targetPainter.paint(&painter);
     painter.endFrame();
 
     // Compare resulting images
     ASSERT_EQ(fbo.toImage(), refFbo.toImage());
 
+    // Paint with color effects
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+    effects[ShaderManager::Effect::Color] = 46;
+    effects[ShaderManager::Effect::Brightness] = 20;
+    effects[ShaderManager::Effect::Ghost] = 84;
+    EXPECT_CALL(target, texture()).WillOnce(Return(texture));
+    EXPECT_CALL(target, graphicEffects()).WillOnce(ReturnRef(effects));
+    EXPECT_CALL(target, updateHullPoints(&fbo));
+    targetPainter.paint(&painter);
+    painter.endFrame();
+    effects.clear();
+
+    // Compare with reference image
+    QBuffer refBuffer1;
+    fbo.toImage().save(&refBuffer1, "png");
+    QFile ref1("color_effects.png");
+    ref1.open(QFile::ReadOnly);
+    refBuffer1.open(QBuffer::ReadOnly);
+    ASSERT_EQ(ref1.readAll(), refBuffer1.readAll());
+
     // Release
     fbo.release();
     refFbo.release();
-
-    context.doneCurrent();
 }