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
  15 namespace IPDF
  16 {
  17         class View;
  18         /**
  19          * Abstract Base class representing how a particular type of object will be rendered
  20          * Includes GPU rendering and CPU rendering
  21          * For GPU rendering, pass GLSL shader source files to constructor in the constructor of a base class
  22          *      To leave unimplemented, just pass NULL filename strings
  23          * For CPU rendering, implement RenderUsingCPU in the derived class
  24          *  To leave unimplemented, just call ObjectRenderer::RenderUsingCPU in the derived class
  25          * The View class uses ObjectRenderer's; see view.h
  26          */
  27         class ObjectRenderer
  28         {
  29                 public:
  30                         /** Construct the ObjectRenderer **/
  31                         ObjectRenderer(const ObjectType & type, const char * vert_glsl_file, const char * frag_glsl_file, const char * geom_glsl_file = "");
  32                         virtual ~ObjectRenderer() {}
  33
  34                         /**
  35                          * Use the GPU to render the objects - GLSL shader approach
  36                          * This way is definitely faster, but subject to the GPU's limitations on precision
  37                          */
  38                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
  39
  40                         /**
  41                          * Use the CPU to render the objects - "make a bitmap and convert it to a texture" approach
  42                          * This way is definitely slower, but gives us more control over the number representations than a GPU
  43                          */
  44
  45                         struct CPURenderTarget
  46                         {
  47                                 uint8_t * pixels;
  48                                 int64_t w;
  49                                 int64_t h;
  50
  51
  52
  53                         };
  54
  55                         static Colour GetColour(const CPURenderTarget & target, int64_t x, int64_t y)
  56                         {
  57                                 int64_t index = 4*(x+y*target.w);
  58                                 return Colour(Real(target.pixels[index+0])/Real(255),
  59                                         Real(target.pixels[index+1])/Real(255),
  60                                         Real(target.pixels[index+2])/Real(255),
  61                                         Real(target.pixels[index+3])/Real(255));
  62                         }
  63
  64                         static void SetColour(const CPURenderTarget & target, int64_t x, int64_t y, const Colour & c)
  65                         {
  66                                 int64_t index = 4*(x+y*target.w);
  67                                 target.pixels[index+0] = c.r*255;
  68                                 target.pixels[index+1] = c.g*255;
  69                                 target.pixels[index+2] = c.b*255;
  70                                 target.pixels[index+3] = c.a*255;
  71                         }
  72
  73                         struct PixelBounds
  74                         {
  75                                 int64_t x; int64_t y; int64_t w; int64_t h;
  76                                 PixelBounds(const Rect & bounds) : x(Double(bounds.x)), y(Double(bounds.y)), w(Double(bounds.w)), h(Double(bounds.h)) {}
  77                         };
  78
  79                         typedef std::pair<int64_t, int64_t> PixelPoint;
  80
  81                         static Rect CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target);
  82                         static PixelPoint CPUPointLocation(const Vec2 & point, const View & view, const CPURenderTarget & target);
  83
  84                         static void SaveBMP(const CPURenderTarget & target, const char * filename);
  85
  86
  87                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id) = 0;
  88
  89
  90
  91                         const ObjectType m_type; /** Type of objects **/
  92                 protected:
  93                         friend class View; //View is a friendly fellow in the world of IPDF
  94                         void PrepareBuffers(unsigned max_size);
  95                         void FinaliseBuffers();
  96                         void AddObjectToBuffers(unsigned index);
  97
  98                         /** Helper for CPU rendering that will render a line using Bresenham's algorithm. Do not use the transpose argument. **/
  99                         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);
 100
 101                         static void FloodFillOnCPU(int64_t x0, int64_t y0, const PixelBounds & bounds, const CPURenderTarget & target, const Colour & fill);
 102
 103                         ShaderProgram m_shader_program; /** GLSL shaders for GPU **/
 104                         GraphicsBuffer m_ibo; /** Index Buffer Object for GPU rendering **/
 105                         std::vector<unsigned> m_indexes; /** Index vector for CPU rendering **/
 106                         BufferBuilder<uint32_t> * m_buffer_builder; /** A BufferBuilder is temporarily used when preparing the ibo and std::vector **/
 107         };
 108
 109         /** Renderer for filled rectangles **/
 110         class RectFilledRenderer : public ObjectRenderer
 111         {
 112                 public:
 113                         RectFilledRenderer() : ObjectRenderer(RECT_FILLED, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl","shaders/rect_filled_geom.glsl") {}
 114                         virtual ~RectFilledRenderer() {}
 115                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 116         };
 117         /** Renderer for outlined rectangles **/
 118         class RectOutlineRenderer : public ObjectRenderer
 119         {
 120                 public:
 121                         RectOutlineRenderer() : ObjectRenderer(RECT_OUTLINE, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
 122                         virtual ~RectOutlineRenderer() {}
 123                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 124         };
 125         /** Renderer for filled circles **/
 126         class CircleFilledRenderer : public ObjectRenderer
 127         {
 128                 public:
 129                         CircleFilledRenderer() : ObjectRenderer(CIRCLE_FILLED, "shaders/rect_vert.glsl", "shaders/circle_frag.glsl", "shaders/circle_filled_geom.glsl") {}
 130                         virtual ~CircleFilledRenderer() {}
 131                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 132         };
 133
 134         /** Renderer for bezier curves **/
 135         class BezierRenderer : public ObjectRenderer
 136         {
 137                 public:
 138                         BezierRenderer() : ObjectRenderer(BEZIER, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/bezier_texbuf_geom.glsl") {}
 139                         virtual ~BezierRenderer() {}
 140                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
 141                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 142                         void PrepareBezierGPUBuffer(const Objects & objects);
 143                 private:
 144                         GraphicsBuffer m_bezier_coeffs;
 145                         GraphicsBuffer m_bezier_ids;
 146                         struct GPUBezierCoeffs
 147                         {
 148                                 float x0, y0;
 149                                 float x1, y1;
 150                                 float x2, y2;
 151                                 float x3, y3;
 152                         };
 153
 154                         GLuint m_bezier_buffer_texture;
 155                         GLuint m_bezier_id_buffer_texture;
 156
 157         };
 158
 159         /** Renderer for filled paths **/
 160         class PathRenderer : public ObjectRenderer
 161         {
 162                 public:
 163                         PathRenderer() : ObjectRenderer(PATH, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
 164                         virtual ~PathRenderer() {}
 165                         virtual void RenderUsingCPU(const Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 166                         // do nothing on GPU
 167                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id) {}
 168         };
 169
 170 }
 171
 172 #endif //_OBJECT_RENDERER_H