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 #define BEZIER_CPU_DECASTELJAU
  15
  16 namespace IPDF
  17 {
  18         class View;
  19         /**
  20          * Abstract Base class representing how a particular type of object will be rendered
  21          * Includes GPU rendering and CPU rendering
  22          * For GPU rendering, pass GLSL shader source files to constructor in the constructor of a base class
  23          *      To leave unimplemented, just pass NULL filename strings
  24          * For CPU rendering, implement RenderUsingCPU in the derived class
  25          *  To leave unimplemented, just call ObjectRenderer::RenderUsingCPU in the derived class
  26          * The View class uses ObjectRenderer's; see view.h
  27          */
  28         class ObjectRenderer
  29         {
  30                 public:
  31                         /** Construct the ObjectRenderer **/
  32                         ObjectRenderer(const ObjectType & type, const char * vert_glsl_file="", const char * frag_glsl_file="", const char * geom_glsl_file = "");
  33                         virtual ~ObjectRenderer() {}
  34
  35                         /**
  36                          * Use the GPU to render the objects - GLSL shader approach
  37                          * This way is definitely faster, but subject to the GPU's limitations on precision
  38                          */
  39                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
  40
  41                         /**
  42                          * Use the CPU to render the objects - "make a bitmap and convert it to a texture" approach
  43                          * This way is definitely slower, but gives us more control over the number representations than a GPU
  44                          */
  45
  46                         struct CPURenderTarget
  47                         {
  48                                 uint8_t * pixels;
  49                                 int64_t w;
  50                                 int64_t h;
  51
  52
  53
  54                         };
  55
  56                         static Colour GetColour(const CPURenderTarget & target, int64_t x, int64_t y)
  57                         {
  58                                 int64_t index = 4*(x+y*target.w);
  59                                 if (index < 0 || index >= 4*(target.w*target.h))
  60                                         return Colour(0,0,0,0);
  61                                 return Colour(target.pixels[index+0],target.pixels[index+1],target.pixels[index+2],target.pixels[index+3]);
  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                                 if (index < 0 || index >= 4*(target.w*target.h))
  68                                         return;
  69
  70                                 target.pixels[index+0] = c.r;
  71                                 target.pixels[index+1] = c.g;
  72                                 target.pixels[index+2] = c.b;
  73                                 target.pixels[index+3] = c.a;
  74                         }
  75
  76                         struct PixelBounds
  77                         {
  78                                 int64_t x; int64_t y; int64_t w; int64_t h;
  79                                 PixelBounds(const Rect & bounds) : x(Double(bounds.x)), y(Double(bounds.y)), w(Double(bounds.w)), h(Double(bounds.h)) {}
  80                         };
  81
  82                         typedef std::pair<int64_t, int64_t> PixelPoint;
  83
  84                         static Rect CPURenderBounds(const Rect & bounds, const View & view, const CPURenderTarget & target);
  85                         static PixelPoint CPUPointLocation(const Vec2 & point, const View & view, const CPURenderTarget & target);
  86
  87                         static void SaveBMP(const CPURenderTarget & target, const char * filename);
  88
  89
  90                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id) = 0;
  91
  92
  93
  94                         const ObjectType m_type; /** Type of objects **/
  95                 protected:
  96                         friend class View; //View is a friendly fellow in the world of IPDF
  97                         void PrepareBuffers(unsigned max_size);
  98                         void FinaliseBuffers();
  99                         void AddObjectToBuffers(unsigned index);
 100
 101                         /** Helper for CPU rendering that will render a line using Bresenham's algorithm. Do not use the transpose argument. **/
 102                         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);
 103
 104                         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));
 105
 106                         ShaderProgram m_shader_program; /** GLSL shaders for GPU **/
 107                         GraphicsBuffer m_ibo; /** Index Buffer Object for GPU rendering **/
 108                         std::vector<unsigned> m_indexes; /** Index vector for CPU rendering **/
 109                         BufferBuilder<uint32_t> * m_buffer_builder; /** A BufferBuilder is temporarily used when preparing the ibo and std::vector **/
 110         };
 111
 112         /** Renderer for filled rectangles **/
 113         class RectFilledRenderer : public ObjectRenderer
 114         {
 115                 public:
 116                         RectFilledRenderer() : ObjectRenderer(RECT_FILLED, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl","shaders/rect_filled_geom.glsl") {}
 117                         virtual ~RectFilledRenderer() {}
 118                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 119         };
 120         /** Renderer for outlined rectangles **/
 121         class RectOutlineRenderer : public ObjectRenderer
 122         {
 123                 public:
 124                         RectOutlineRenderer() : ObjectRenderer(RECT_OUTLINE, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/rect_outline_geom.glsl") {}
 125                         virtual ~RectOutlineRenderer() {}
 126                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 127         };
 128         /** Renderer for filled circles **/
 129         class CircleFilledRenderer : public ObjectRenderer
 130         {
 131                 public:
 132                         CircleFilledRenderer() : ObjectRenderer(CIRCLE_FILLED, "shaders/rect_vert.glsl", "shaders/circle_frag.glsl", "shaders/circle_filled_geom.glsl") {}
 133                         virtual ~CircleFilledRenderer() {}
 134                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 135         };
 136
 137         /** Renderer for bezier curves **/
 138         class BezierRenderer : public ObjectRenderer
 139         {
 140                 public:
 141                         BezierRenderer() : ObjectRenderer(BEZIER, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/bezier_texbuf_geom.glsl") {}
 142                         virtual ~BezierRenderer() {}
 143                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id);
 144                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 145                         void PrepareBezierGPUBuffer(Objects & objects);
 146
 147                         static void RenderBezierOnCPU(const Bezier & relative, const Rect & bounds, const View & view, const CPURenderTarget & target, const Colour & c=Colour(0,0,0,255));
 148
 149                 private:
 150                         GraphicsBuffer m_bezier_coeffs;
 151                         GraphicsBuffer m_bezier_ids;
 152                         struct GPUBezierCoeffs
 153                         {
 154                                 float x0, y0;
 155                                 float x1, y1;
 156                                 float x2, y2;
 157                                 float x3, y3;
 158                         };
 159
 160                         GLuint m_bezier_buffer_texture;
 161                         GLuint m_bezier_id_buffer_texture;
 162
 163         };
 164
 165         /** Renderer for filled paths **/
 166         class PathRenderer : public ObjectRenderer
 167         {
 168                 public:
 169                         PathRenderer() : ObjectRenderer(PATH, "shaders/rect_vert.glsl", "shaders/rect_frag.glsl", "shaders/bezier_texbug_geom.glsl") {}
 170                         virtual ~PathRenderer() {}
 171                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id);
 172                         // do nothing on GPU
 173                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id) {}
 174
 175         };
 176
 177         class FakeRenderer : public ObjectRenderer
 178         {
 179                 public:
 180                         FakeRenderer() : ObjectRenderer(PATH,NULL,NULL,NULL) {}
 181                         ~FakeRenderer() {}
 182                         virtual void RenderUsingCPU(Objects & objects, const View & view, const CPURenderTarget & target, unsigned first_obj_id, unsigned last_obj_id) {}
 183                         virtual void RenderUsingGPU(unsigned first_obj_id, unsigned last_obj_id) {}
 184         };
 185
 186 }
 187
 188 #endif //_OBJECT_RENDERER_H