src/framebuffer.cpp

   1 #include "framebuffer.h"
   2 #include "gl_core44.h"
   3
   4 using namespace IPDF;
   5
   6 void FrameBuffer::Create(int w, int h)
   7 {
   8         if (m_render_texture)
   9         {
  10                 // FrameBuffer was already Created, destroy it before creating again
  11                 Destroy();
  12         }
  13         m_width = w;
  14         m_height = h;
  15         glGenTextures(1, &m_render_texture);
  16         glGenFramebuffers(1, &m_render_fbo);
  17
  18         glBindTexture(GL_TEXTURE_2D, m_render_texture);
  19         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
  20
  21         glBindFramebuffer(GL_FRAMEBUFFER, m_render_fbo);
  22
  23         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_render_texture, 0);
  24
  25         glBindFramebuffer(GL_FRAMEBUFFER, 0);
  26         glBindTexture(GL_TEXTURE_2D, 0);
  27 }
  28
  29 void FrameBuffer::Destroy()
  30 {
  31         if (!m_render_texture) return; // wasn't Created (or already Destroyed)
  32         glDeleteFramebuffers(1, &m_render_fbo);
  33         glDeleteTextures(1, &m_render_texture);
  34 }
  35
  36 void FrameBuffer::Bind()
  37 {
  38         // will draw to this FrameBuffer
  39         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_render_fbo);
  40 }
  41
  42 void FrameBuffer::UnBind()
  43 {
  44         glBindFramebuffer(GL_FRAMEBUFFER, 0); // will both draw to and read pixels from screen
  45 }
  46
  47 void FrameBuffer::Blit()
  48 {
  49         glBindFramebuffer(GL_READ_FRAMEBUFFER, m_render_fbo); // read pixels from this FrameBuffer
  50         glBlitFramebuffer(0, 0, m_width, m_height, 0, 0, m_width, m_height, GL_COLOR_BUFFER_BIT, GL_NEAREST); // draw pixels
  51 }
  52
  53 void FrameBuffer::Clear(float r, float g, float b, float a)
  54 {
  55         Bind();
  56         glClearColor(r,g,b,a);
  57         glClear(GL_COLOR_BUFFER_BIT);
  58 }
  59