src/objectrenderer.h

   1 /**
   2  * @file objectrenderer.h
   3  * @brief Definition of ObjectRenderer class
   4  */
   5
   6 #ifndef _OBJECT_RENDERER_H
   7 #define _OBJECT_RENDERER_H
   8
   9 #include "ipdf.h"
  10 #include "graphicsbuffer.h"
  11 #include "shaderprogram.h"
  12 #include "bufferbuilder.h"
  13
  14 namespace IPDF
  15 {
  16         class View;
  17         /**
  18          * Abstract Base class representing how a particular type of object will be rendered
  19          * Includes GPU rendering and CPU rendering
  20          * For GPU rendering, pass GLSL shader source files to constructor in the constructor of a base class
  21          *      To leave unimplemented, just pass NULL filename strings
  22          * For CPU rendering, implement RenderUsingCPU in the derived class
  23          *  To leave unimplemented, just call ObjectRenderer::RenderUsingCPU in the derived class
  24          * The View class uses ObjectRenderer's; see view.h
  25          */
  26         class ObjectRenderer
  27         {
  28                 public:
  29                         /** Construct the ObjectRenderer **/
  30                         ObjectRenderer(const ObjectType & type, const char * vert_glsl_file, const char * frag_glsl_file, const char * geom_glsl_file = "");
  31                         virtual ~ObjectRenderer() {}
  32
  33                         /**
  34                          * Use the GPU to render the objects - GLSL shader approach
  35                          * This way is definitely faster, but subject to the GPU's limitations on precision
  36                          */
  37                         virtual void RenderUsingGPU();
  38
  39                         /**
  40                          * Use the CPU to render the objects - "make a bitmap and convert it to a texture" approach
  41                          * This way is definitely slower, but gives us more control over the number representations than a GPU
  42                          */
  43
  44                         struct CPURenderTarget
  45                         {
  46                                 uint8_t * pixels;
  47                                 int64_t w;
  48                                 int64_t h;
  49                         };
  50                         struct PixelBounds
  51                         {
  52                                 int64_t x; int64_t y; int64_t w; int64_t h;
  53                                 PixelBounds(const Rect & bounds) : x(Double(bounds.x)), y(Double(bounds.y)), w(Double(bounds.w)), h(Double(bounds.h)) {}
  54                         };
  55
  56                         static Rect CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target);
  57
  58
  59                         static void SaveBMP(const CPURenderTarget & target, const char * filename);
  60
  61
  62                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target) = 0;
  63
  64
  65
  66                         const ObjectType m_type; /** Type of objects **/
  67                 protected:
  68                         friend class View; //View is a friendly fellow in the world of IPDF
  69                         void PrepareBuffers(unsigned max_size);
  70                         void FinaliseBuffers();
  71                         void AddObjectToBuffers(unsigned index);
  72
  73                         /** Helper for CPU rendering that will render a line using Bresenham's algorithm. Do not use the transpose argument. **/
  74                         static void RenderLineOnCPU(int64_t x0, int64_t y0, int64_t x1, int64_t y1, const CPURenderTarget & target, const Colour & colour = Colour(0,0,0,1), bool transpose = false);
  75
  76                         ShaderProgram m_shader_program; /** GLSL shaders for GPU **/
  77                         GraphicsBuffer m_ibo; /** Index Buffer Object for GPU rendering **/
  78                         std::vector<unsigned> m_indexes; /** Index vector for CPU rendering **/
  79                         BufferBuilder<uint32_t> * m_buffer_builder; /** A BufferBuilder is temporarily used when preparing the ibo and std::vector **/
  80         };
  81
  82         /** Renderer for filled rectangles **/
  83         class RectFilledRenderer : public ObjectRenderer
  84         {
  85                 public:
  86                         RectFilledRenderer() : ObjectRenderer(RECT_FILLED, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl","shaders/rect_filled_geom.glsl") {}
  87                         virtual ~RectFilledRenderer() {}
  88                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target);
  89         };
  90         /** Renderer for outlined rectangles **/
  91         class RectOutlineRenderer : public ObjectRenderer
  92         {
  93                 public:
  94                         RectOutlineRenderer() : ObjectRenderer(RECT_OUTLINE, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
  95                         virtual ~RectOutlineRenderer() {}
  96                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target);
  97         };
  98         /** Renderer for filled circles **/
  99         class CircleFilledRenderer : public ObjectRenderer
 100         {
 101                 public:
 102                         CircleFilledRenderer() : ObjectRenderer(CIRCLE_FILLED, "shaders/rect_vert.glsl", "shaders/circle_frag.glsl", "shaders/circle_filled_geom.glsl") {}
 103                         virtual ~CircleFilledRenderer() {}
 104                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target);
 105         };
 106
 107         /** Renderer for bezier curves **/
 108         class BezierRenderer : public ObjectRenderer
 109         {
 110                 public:
 111                         BezierRenderer() : ObjectRenderer(BEZIER, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/bezier_texbuf_geom.glsl") {}
 112                         virtual ~BezierRenderer() {}
 113                         virtual void RenderUsingGPU();
 114                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target);
 115                         void PrepareBezierGPUBuffer(const Objects & objects);
 116                 private:
 117                         GraphicsBuffer m_bezier_coeffs;
 118                         GraphicsBuffer m_bezier_ids;
 119                         struct GPUBezierCoeffs
 120                         {
 121                                 float x0, y0;
 122                                 float x1, y1;
 123                                 float x2, y2;
 124                         };
 125
 126                         GLuint m_bezier_buffer_texture;
 127                         GLuint m_bezier_id_buffer_texture;
 128
 129         };
 130 }
 131
 132 #endif //_OBJECT_RENDERER_H