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                                 if (index < 0 || index >= 4*(target.w*target.h))
  59                                         return Colour(0,0,0,0);
  60                                 return Colour(target.pixels[index+0],target.pixels[index+1],target.pixels[index+2],target.pixels[index+3]);
  61                         }
  62
  63                         static void SetColour(const CPURenderTarget & target, int64_t x, int64_t y, const Colour & c)
  64                         {
  65                                 int64_t index = 4*(x+y*target.w);
  66                                 if (index < 0 || index >= 4*(target.w*target.h))
  67                                         return;
  68
  69                                 target.pixels[index+0] = c.r;
  70                                 target.pixels[index+1] = c.g;
  71                                 target.pixels[index+2] = c.b;
  72                                 target.pixels[index+3] = c.a;
  73                         }
  74
  75                         struct PixelBounds
  76                         {
  77                                 int64_t x; int64_t y; int64_t w; int64_t h;
  78                                 PixelBounds(const Rect & bounds) : x(Double(bounds.x)), y(Double(bounds.y)), w(Double(bounds.w)), h(Double(bounds.h)) {}
  79                         };
  80
  81                         typedef std::pair<int64_t, int64_t> PixelPoint;
  82
  83                         static Rect CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target);
  84                         static PixelPoint CPUPointLocation(const Vec2 & point, const View & view, const CPURenderTarget & target);
  85
  86                         static void SaveBMP(const CPURenderTarget & target, const char * filename);
  87
  88
  89                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id) = 0;
  90
  91
  92
  93                         const ObjectType m_type; /** Type of objects **/
  94                 protected:
  95                         friend class View; //View is a friendly fellow in the world of IPDF
  96                         void PrepareBuffers(unsigned max_size);
  97                         void FinaliseBuffers();
  98                         void AddObjectToBuffers(unsigned index);
  99
 100                         /** Helper for CPU rendering that will render a line using Bresenham's algorithm. Do not use the transpose argument. **/
 101                         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);
 102
 103                         static void FloodFillOnCPU(int64_t x0, int64_t y0, const PixelBounds & bounds, const CPURenderTarget & target, const Colour & fill, const Colour & stroke=Colour(0,0,0,0));
 104
 105                         ShaderProgram m_shader_program; /** GLSL shaders for GPU **/
 106                         GraphicsBuffer m_ibo; /** Index Buffer Object for GPU rendering **/
 107                         std::vector<unsigned> m_indexes; /** Index vector for CPU rendering **/
 108                         BufferBuilder<uint32_t> * m_buffer_builder; /** A BufferBuilder is temporarily used when preparing the ibo and std::vector **/
 109         };
 110
 111         /** Renderer for filled rectangles **/
 112         class RectFilledRenderer : public ObjectRenderer
 113         {
 114                 public:
 115                         RectFilledRenderer() : ObjectRenderer(RECT_FILLED, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl","shaders/rect_filled_geom.glsl") {}
 116                         virtual ~RectFilledRenderer() {}
 117                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 118         };
 119         /** Renderer for outlined rectangles **/
 120         class RectOutlineRenderer : public ObjectRenderer
 121         {
 122                 public:
 123                         RectOutlineRenderer() : ObjectRenderer(RECT_OUTLINE, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
 124                         virtual ~RectOutlineRenderer() {}
 125                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 126         };
 127         /** Renderer for filled circles **/
 128         class CircleFilledRenderer : public ObjectRenderer
 129         {
 130                 public:
 131                         CircleFilledRenderer() : ObjectRenderer(CIRCLE_FILLED, "shaders/rect_vert.glsl", "shaders/circle_frag.glsl", "shaders/circle_filled_geom.glsl") {}
 132                         virtual ~CircleFilledRenderer() {}
 133                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 134         };
 135
 136         /** Renderer for bezier curves **/
 137         class BezierRenderer : public ObjectRenderer
 138         {
 139                 public:
 140                         BezierRenderer() : ObjectRenderer(BEZIER, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/bezier_texbuf_geom.glsl") {}
 141                         virtual ~BezierRenderer() {}
 142                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
 143                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 144                         void PrepareBezierGPUBuffer(Objects & objects);
 145
 146                         static void RenderBezierOnCPU(unsigned index, Objects & objects, const View & view, const CPURenderTarget & target, const Colour & c=Colour(0,0,0,255));
 147
 148                 private:
 149                         GraphicsBuffer m_bezier_coeffs;
 150                         GraphicsBuffer m_bezier_ids;
 151                         struct GPUBezierCoeffs
 152                         {
 153                                 float x0, y0;
 154                                 float x1, y1;
 155                                 float x2, y2;
 156                                 float x3, y3;
 157                         };
 158
 159                         GLuint m_bezier_buffer_texture;
 160                         GLuint m_bezier_id_buffer_texture;
 161
 162         };
 163
 164         /** Renderer for filled paths **/
 165         class PathRenderer : public ObjectRenderer
 166         {
 167                 public:
 168                         PathRenderer() : ObjectRenderer(PATH, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
 169                         virtual ~PathRenderer() {}
 170                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 171                         // do nothing on GPU
 172                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id) {}
 173         };
 174
 175         class FakeRenderer : public ObjectRenderer
 176         {
 177                 public:
 178                         FakeRenderer() : ObjectRenderer(PATH,NULL,NULL,NULL) {}
 179                         ~FakeRenderer() {}
 180                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id) {}
 181                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id) {}
 182         };
 183
 184 }
 185
 186 #endif //_OBJECT_RENDERER_H