FBO working as expected, render background on menu state

src/engine.cpp

@@ -68,6 +68,8 @@ void Engine::init()
 
 void Engine::terminate()
 {
+    changeState(NULL);
+
     // save configs
     g_config.setValue("width", Platform::getWindowWidth());
     g_config.setValue("height", Platform::getWindowHeight());

src/framebuffer.cpp

@@ -24,25 +24,31 @@
 #define GL_GLEXT_PROTOTYPES
 
 #include "framebuffer.h"
+#include "platform.h"
+#include "graphics.h"
+#include "logger.h"
 
 #include <GL/glext.h>
 #include <GL/glu.h>
-#include "platform.h"
-#include "graphics.h"
 
-FrameBuffer::FrameBuffer(int width, int height) :
+FrameBuffer::FrameBuffer(int width, int height)
-    m_fbo(0)
 {
+    m_fbo = 0;
     m_width = width;
     m_height = height;
 
-    // texture where the framebuffer will be store
+    // create FBO texture
-    m_frameTexture = TexturePtr(new Texture(width, height, 4));
+    glGenTextures(1, &m_fboTexture);
+    glBindTexture(GL_TEXTURE_2D, m_fboTexture);
+    glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
-    // we want a smooth framebuffer
+    // we want bilinear filtering (for a smooth framebuffer)
-    m_frameTexture->enableBilinearFilter();
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
-    // use FBO only if supported
+    // use FBO ext only if supported
     if(Platform::isExtensionSupported("EXT_framebuffer_object")) {
         m_fallbackOldImp = false;
 
@@ -51,18 +57,14 @@ FrameBuffer::FrameBuffer(int width, int height) :
         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);
 
         // attach 2D texture to this FBO
-        glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, m_frameTexture->getTextureId(), 0);
+        glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, m_fboTexture, 0);
-
-        // must be called before checking
-        glDrawBuffer(GL_NONE);
-        glReadBuffer(GL_NONE);
 
         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
         switch(status) {
             case GL_FRAMEBUFFER_COMPLETE_EXT:
                 //ok
                 break;
-            default:
+            default: // fallback to old implementation
                 m_fallbackOldImp = true;
                 break;
         }
@@ -74,6 +76,7 @@ FrameBuffer::FrameBuffer(int width, int height) :
 
 FrameBuffer::~FrameBuffer()
 {
+    glDeleteTextures(1, &m_fboTexture);
     if(m_fbo)
         glDeleteFramebuffersEXT(1, &m_fbo);
 }
@@ -83,18 +86,21 @@ void FrameBuffer::bind()
     if(!m_fallbackOldImp) {
         // bind framebuffer
         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);
-
-        // must be called before rendering to framebuffer
-        glDrawBuffer(GL_NONE);
-        glReadBuffer(GL_NONE);
     }
 
+    // setup framebuffer viewport
+    glViewport(0, 0, m_width, m_height);
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluOrtho2D(0.0f, m_width, 0, m_height);
+
+    // back to model view
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
     // clear framebuffer
     glClearColor(0.0, 0.0, 0.0, 0.0);
     glClear(GL_COLOR_BUFFER_BIT);
-
-    // setup framebuffer viewport
-    g_graphics.setViewport(m_width, m_height);
 }
 
 void FrameBuffer::unbind()
@@ -102,19 +108,32 @@ void FrameBuffer::unbind()
     if(!m_fallbackOldImp) {
         // bind back buffer again
         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
-
-        // must be called to render to back buffer again
         glDrawBuffer(GL_BACK);
         glReadBuffer(GL_BACK);
+
+        // restore graphics viewport
+        g_graphics.restoreViewport();
     } else {
         // copy screen to texture
-        m_frameTexture->copyFromScreen(0, 0, 0, 0, m_width, m_height);
+        glBindTexture(GL_TEXTURE_2D, m_fboTexture);
+        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, m_width, m_height);
+
+        // restore graphics viewport
+        g_graphics.restoreViewport();
 
         // clear screen
-        glClearColor(0.0, 0.0, 0.0, 0.0);
+        glClearColor(0.0, 0.0, 0.0, 1.0);
         glClear(GL_COLOR_BUFFER_BIT);
     }
-
+}
-    // restore graphics viewport
+
-    g_graphics.restoreViewport();
+void FrameBuffer::draw(int x, int y, int width, int height)
+{
+    glBindTexture(GL_TEXTURE_2D, m_fboTexture);
+    glBegin(GL_QUADS);
+    glTexCoord2i(0, 0); glVertex2i(x,       y);
+    glTexCoord2i(0, 1); glVertex2i(x,       y+height);
+    glTexCoord2i(1, 1); glVertex2i(x+width, y+height);
+    glTexCoord2i(1, 0); glVertex2i(x+width, y);
+    glEnd();
 }

src/framebuffer.h

@@ -25,24 +25,25 @@
 #ifndef FRAMEBUFFER_H
 #define FRAMEBUFFER_H
 
-#include "texture.h"
+#include <GL/gl.h>
 
 class FrameBuffer
 {
+public:
     FrameBuffer(int width, int height);
     virtual ~FrameBuffer();
 
-    /// Return the texture where everything was drawn
-    TexturePtr getFramebufferTexture();
-
     /// Bind the framebuffer, everything rendered will be draw on it
     void bind();
 
     /// Unbind the framebuffer, render on back buffer again
     void unbind();
 
+    /// Draw framebuffer
+    void draw(int x, int y, int width, int height);
+
 private:
-    TexturePtr m_frameTexture;
+    GLuint m_fboTexture;
     GLuint m_fbo;
     bool m_fallbackOldImp;
     int m_width;

src/graphics.cpp

@@ -27,6 +27,7 @@
 
 #include <GL/gl.h>
 #include <GL/glu.h>
+#include "texture.h"
 
 Graphics g_graphics;
 
@@ -43,10 +44,10 @@ Graphics::~Graphics()
 void Graphics::init()
 {
     // setup opengl
-    glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // black background
+    glEnable(GL_ALPHA_TEST); // enable alpha by default
-    glEnable(GL_ALPHA_TEST); // enable alpha
     glAlphaFunc(GL_GREATER, 0.0f); // default alpha mode
     glDisable(GL_DEPTH_TEST); // we are rendering 2D only, we don't need it
+    glEnable(GL_TEXTURE_2D); // enable textures by default
 
     notice("GPU %s", (const char*)glGetString(GL_RENDERER));
     notice("OpenGL %s", (const char*)glGetString(GL_VERSION));
@@ -64,13 +65,13 @@ void Graphics::resize(int width, int height)
     restoreViewport();
 }
 
-void Graphics::setViewport(int width, int height)
+void Graphics::restoreViewport()
 {
     // resize gl viewport
-    glViewport(0, 0, width, height);
+    glViewport(0, 0, m_width, m_height);
 
     /*
-     0 ,0---------0,w**
+     0,0---------0,w
      |           |
      |           |
      |           |
@@ -79,7 +80,7 @@ void Graphics::setViewport(int width, int height)
     // setup view region like above
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
-    gluOrtho2D(0.0f, width, height, 0.0f);
+    gluOrtho2D(0.0f, m_width, m_height, 0.0f);
 
     // back to model view
     glMatrixMode(GL_MODELVIEW);
@@ -88,6 +89,7 @@ void Graphics::setViewport(int width, int height)
 
 void Graphics::beginRender()
 {
+    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
     glClear(GL_COLOR_BUFFER_BIT);
     glLoadIdentity();
 }

src/graphics.h

@@ -25,6 +25,8 @@
 #ifndef GRAPHICS_H
 #define GRAPHICS_H
 
+class Texture;
+
 class Graphics
 {
 public:
@@ -37,18 +39,15 @@ public:
     /// Called after every window resize
     void resize(int width, int height);
 
+    /// Restore original viewport
+    void restoreViewport();
+
     /// Called before every render
     void beginRender();
 
     /// Called after every render
     void endRender();
 
-    /// Restore original viewport
-    void restoreViewport() { setViewport(m_width, m_height); }
-
-    /// Set viewport, used by FrameBuffer
-    void setViewport(int width, int height);
-
     int getWidth() { return m_width; }
     int getHeight() { return m_height; }
 

src/main.cpp

@@ -70,6 +70,7 @@ int main(int argc, const char *argv[])
     g_resources.init(argv[0]);
     if(g_resources.setWriteDir(Platform::getAppUserDir()))
         g_resources.addToSearchPath(Platform::getAppUserDir());
+    g_resources.addToSearchPath("data");
 
     // before loading configurations set the default ones
     setDefaultConfigs();

src/menustate.cpp

@@ -26,9 +26,15 @@
 #include "framebuffer.h"
 #include "graphics.h"
 #include "texturemanager.h"
+#include "logger.h"
+#include "engine.h"
+
+FrameBuffer *fbo;
+TexturePtr background;
 
 MenuState::MenuState()
 {
+
 }
 
 MenuState::~MenuState()
@@ -38,7 +44,8 @@ MenuState::~MenuState()
 
 void MenuState::onEnter()
 {
-
+    background = g_textures.get("background.png");
+    background->enableBilinearFilter();
 }
 
 void MenuState::onLeave()
@@ -48,17 +55,52 @@ void MenuState::onLeave()
 
 void MenuState::onClose()
 {
-
+    g_engine.stop();
 }
 
 void MenuState::onInputEvent(InputEvent* event)
 {
-
 }
 
 void MenuState::render()
 {
+    // draw background
+    background->bind();
 
+    int x = 0;
+    int y = 0;
+    int screenWidth = g_graphics.getWidth();
+    int screenHeight = g_graphics.getHeight();
+    int textureWidth = background->getWidth();
+    int textureHeight = background->getHeight();
+
+    int texCoordX;
+    int texCoordY;
+    int texCoordWidth;
+    int texCoordHeight;
+
+    int wantedWidth = 1240;
+    int wantedHeight = 880;
+
+    float originalRatio = (float)wantedWidth/wantedHeight;
+    float screenRatio = (float)screenWidth/screenHeight;
+    if(screenRatio >= originalRatio) {
+        texCoordHeight = wantedHeight;
+        texCoordWidth = std::min((int)(wantedHeight*screenRatio), textureWidth);
+    } else {
+        texCoordWidth = wantedWidth;
+        texCoordHeight = std::min((int)(wantedWidth/screenRatio), textureHeight);
+    }
+    texCoordX = textureWidth - texCoordWidth;
+    texCoordY = textureHeight - texCoordHeight;
+
+
+    glBegin(GL_QUADS);
+    glTexCoord2f((float)texCoordX/textureWidth,                 (float)texCoordY/textureHeight); glVertex2i(x,       y);
+    glTexCoord2f((float)texCoordX/textureWidth,                 (float)(texCoordY+texCoordHeight)/textureHeight); glVertex2i(x,       y+screenHeight);
+    glTexCoord2f((float)(texCoordX+texCoordWidth)/textureWidth, (float)(texCoordY+texCoordHeight)/textureHeight); glVertex2i(x+screenWidth, y+screenHeight);
+    glTexCoord2f((float)(texCoordX+texCoordWidth)/textureWidth, (float)texCoordY/textureHeight); glVertex2i(x+screenWidth, y);
+    glEnd();
 }
 
 void MenuState::update(int elapsedTicks)

src/texture.cpp

@@ -62,7 +62,7 @@ Texture::Texture(int width, int height, int components, unsigned char *pixels)
 
 Texture::~Texture()
 {
-    if(m_textureId > 0)
+    if(m_textureId)
         glDeleteTextures(1, &m_textureId);
 }
 
@@ -73,14 +73,23 @@ void Texture::bind()
 
 void Texture::enableBilinearFilter()
 {
-    bind();
+    glBindTexture(GL_TEXTURE_2D, m_textureId);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 }
 
-void Texture::copyFromScreen(int xoffset, int yoffset, int x, int y, int width, int height)
+void Texture::draw(int x, int y)
 {
-    bind();
+    draw(x, y, m_width, m_height);
-    glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, width, height);
 }
 
+void Texture::draw(int x, int y, int width, int height)
+{
+    glBindTexture(GL_TEXTURE_2D, m_textureId);
+    glBegin(GL_QUADS);
+    glTexCoord2i(0, 0); glVertex2i(x,       y);
+    glTexCoord2i(0, 1); glVertex2i(x,       y+height);
+    glTexCoord2i(1, 1); glVertex2i(x+width, y+height);
+    glTexCoord2i(1, 0); glVertex2i(x+width, y);
+    glEnd();
+}

src/texture.h

@@ -43,12 +43,11 @@ public:
     /// Enable texture bilinear filter (smooth scaled textures)
     void enableBilinearFilter();
 
-    /// Copy screen pixels to texture
+    void draw(int x, int y);
-    void copyFromScreen(int xoffset, int yoffset, int x, int y, int width, int height);
+    void draw(int x, int y, int width, int height);
 
     int getWidth() const { return m_width; }
     int getHeight() const { return m_height; }
-    GLuint getTextureId() const { return m_textureId; }
 
 private:
     GLuint m_textureId;