tested and fixed rasterizer

include/scigl_render/example/depth_offscreen_render.hpp

@@ -2,6 +2,7 @@
 #include <scigl_render/gl_context.hpp>
 #include <scigl_render/render/depth_simulator.hpp>
 #include <scigl_render/render/offscreen_render.hpp>
+#include <scigl_render/render/rasterizer.hpp>
 #include <scigl_render/render/texture_fullscreen_render.hpp>
 #include <memory>
 #include <vector>
@@ -56,8 +57,8 @@ private:
   TextureFullscreenRender texture_render;
   // buffer for reading from the offscreen render
   std::vector<unsigned char> image_buffer;
-  // renders the 3D scene
-  Shader scene_shader;
+  // display different views
+  Rasterizer rasterizer;
 
   /*!
   Display the data from the framebuffer

src/example/depth_offscreen_render.cpp

@@ -22,7 +22,10 @@ DepthOffscreenRender::DepthOffscreenRender(
                      gl_context->get_height(),
                      tex_internal_format),
       image_buffer(gl_context->get_width() * gl_context->get_height() *
-                   pixel_size)
+                   pixel_size),
+      rasterizer(gl_context->get_width() / 2,
+                 gl_context->get_height() / 2,
+                 2, 2)
 {
   check_gl_error("example render created");
 }
@@ -34,12 +37,21 @@ void DepthOffscreenRender::next_frame(
 {
   using namespace std::placeholders;
   check_gl_error("next frame begin");
-  // render to fbo
+  // clear all the space
   offscreen_render.clear_fbo();
   offscreen_render.activate_fbo();
   check_gl_error("activated fbo");
-  depth_simulator->render_pose(model_pose.to_quaternion_pose(),
-                               camera_pose.to_quaternion_pose());
+  // render 4 poses via rasterization
+  for (int i = 0; i < 4; i++)
+  {
+    auto m_pose = model_pose;
+    m_pose.orientation.x += i * M_PI_2;
+    rasterizer.activate_view(i);
+    depth_simulator->render_pose(m_pose.to_quaternion_pose(),
+                                 camera_pose.to_quaternion_pose());
+  }
+  // back to default
+  rasterizer.activate_all();
   offscreen_render.deactivate_fbo();
   // read asynchronously using the pbos
   offscreen_render.start_read(texture_format, texture_type);

src/render/rasterizer.cpp

@@ -11,7 +11,7 @@ Rasterizer::Rasterizer(size_t width, size_t height, size_t views_per_row,
 {
   // create the offscreen render object
   texture_width = width * views_per_row;
-  texture_height = width * views_per_column;
+  texture_height = height * views_per_column;
 }
 
 void Rasterizer::activate_view(size_t row, size_t column)