source/renderer.cpp

   1 /* $Id$
   2
   3 This file is part of libmspgl
   4 Copyright © 2011  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #include <msp/core/except.h>
   9 #include "batch.h"
  10 #include "buffer.h"
  11 #include "camera.h"
  12 #include "material.h"
  13 #include "program.h"
  14 #include "programdata.h"
  15 #include "renderer.h"
  16 #include "texture.h"
  17 #include "texturing.h"
  18 #include "vertexarray.h"
  19
  20 using namespace std;
  21
  22 namespace Msp {
  23 namespace GL {
  24
  25 Renderer::Renderer(const Camera *c):
  26         mtx_stack(*this),
  27         mtx_changed(false),
  28         camera(c),
  29         state_stack(1),
  30         state(&state_stack.back()),
  31         vertex_array(0),
  32         vertex_array_changed(false),
  33         element_buffer(0)
  34 {
  35         MatrixStack::modelview().push();
  36         if(camera)
  37         {
  38                 MatrixStack::projection().push();
  39                 camera->apply();
  40                 mtx_stack.load(camera->get_matrix());
  41         }
  42         else
  43                 mtx_stack.load(MatrixStack::modelview().top());
  44 }
  45
  46 Renderer::~Renderer()
  47 {
  48         if(camera)
  49                 MatrixStack::projection().pop();
  50         MatrixStack::modelview().pop();
  51
  52         Texturing::unbind();
  53         Texture::unbind_from(0);
  54         Material::unbind();
  55         Program::unbind();
  56         Buffer::unbind_from(ELEMENT_ARRAY_BUFFER);
  57 }
  58
  59 void Renderer::set_texture(const Texture *t)
  60 {
  61         state->texture = t;
  62         state->texturing = 0;
  63 }
  64
  65 void Renderer::set_texturing(const Texturing *t)
  66 {
  67         state->texturing = t;
  68         state->texture = 0;
  69 }
  70
  71 void Renderer::set_material(const Material *m)
  72 {
  73         state->material = m;
  74 }
  75
  76 void Renderer::set_shader(const Program *p, const ProgramData *d)
  77 {
  78         state->shprog = p;
  79         if(d)
  80                 state->shdata.assign(1, d);
  81         else
  82                 state->shdata.clear();
  83 }
  84
  85 void Renderer::add_shader_data(const ProgramData *d)
  86 {
  87         if(!state->shprog)
  88                 throw InvalidState("No shader program");
  89
  90         state->shdata.push_back(d);
  91 }
  92
  93 void Renderer::set_vertex_array(const VertexArray *a)
  94 {
  95         vertex_array_changed = (a!=vertex_array);
  96         vertex_array = a;
  97 }
  98
  99 void Renderer::set_element_buffer(const Buffer *b)
 100 {
 101         element_buffer = b;
 102 }
 103
 104 void Renderer::push_state()
 105 {
 106         state_stack.push_back(state_stack.back());
 107         state = &state_stack.back();
 108         mtx_stack.push();
 109 }
 110
 111 void Renderer::pop_state()
 112 {
 113         if(state_stack.size()==1)
 114                 throw InvalidState("Can't pop the last state");
 115
 116         state_stack.pop_back();
 117         state = &state_stack.back();
 118         mtx_stack.pop();
 119         mtx_changed = true;
 120 }
 121
 122 void Renderer::escape()
 123 {
 124         apply_state();
 125         Buffer::unbind_from(ELEMENT_ARRAY_BUFFER);
 126 }
 127
 128 void Renderer::draw(const Batch &batch)
 129 {
 130         if(!vertex_array)
 131                 throw InvalidState("Can't draw without a vertex array");
 132
 133         apply_state();
 134
 135         // Until VertexArray acquires VAO support and becomes Bindable
 136         if(vertex_array_changed)
 137                 vertex_array->apply();
 138
 139         if(element_buffer)
 140                 element_buffer->bind_to(ELEMENT_ARRAY_BUFFER);
 141         else
 142                 Buffer::unbind_from(ELEMENT_ARRAY_BUFFER);
 143
 144         batch.draw();
 145 }
 146
 147 void Renderer::apply_state()
 148 {
 149         // We let the objects themselves figure out if the binding has changed
 150
 151         if(state->texturing)
 152                 state->texturing->bind();
 153         else
 154         {
 155                 Texturing::unbind();
 156                 if(state->texture)
 157                         state->texture->bind_to(0);
 158                 else
 159                         Texture::unbind_from(0);
 160         }
 161
 162         if(state->material)
 163                 state->material->bind();
 164         else
 165                 Material::unbind();
 166
 167         if(state->shprog)
 168         {
 169                 state->shprog->bind();
 170                 for(vector<const ProgramData *>::const_iterator i=state->shdata.begin(); i!=state->shdata.end(); ++i)
 171                         (*i)->apply();
 172         }
 173         else
 174                 Program::unbind();
 175
 176         if(mtx_changed)
 177         {
 178                 MatrixStack::modelview() = mtx_stack.top();
 179                 mtx_changed = false;
 180         }
 181 }
 182
 183
 184 Renderer::State::State():
 185         texture(0),
 186         texturing(0),
 187         material(0),
 188         shprog(0)
 189 { }
 190
 191
 192 Renderer::MtxStack::MtxStack(Renderer &r):
 193         renderer(r)
 194 { }
 195
 196 void Renderer::MtxStack::update()
 197 {
 198         renderer.mtx_changed = true;
 199 }
 200
 201 } // namespace GL
 202 } // namespace Msp