src/graphicsbuffer.cpp

   1 #include "graphicsbuffer.h"
   2 #include "log.h"
   3
   4 using namespace IPDF;
   5
   6 static GLenum BufferUsageToGLUsage(GraphicsBuffer::BufferUsage buffer_usage)
   7 {
   8         GLenum usage;
   9         switch (buffer_usage)
  10         {
  11         case GraphicsBuffer::BufferUsageStaticDraw:
  12                 usage = GL_STATIC_DRAW;
  13                 break;
  14         case GraphicsBuffer::BufferUsageStaticRead:
  15                 usage = GL_STATIC_READ;
  16                 break;
  17         case GraphicsBuffer::BufferUsageStaticCopy:
  18                 usage = GL_STATIC_COPY;
  19                 break;
  20         case GraphicsBuffer::BufferUsageDynamicDraw:
  21                 usage = GL_DYNAMIC_DRAW;
  22                 break;
  23         case GraphicsBuffer::BufferUsageDynamicRead:
  24                 usage = GL_DYNAMIC_READ;
  25                 break;
  26         case GraphicsBuffer::BufferUsageDynamicCopy:
  27                 usage = GL_DYNAMIC_COPY;
  28                 break;
  29         case GraphicsBuffer::BufferUsageStreamDraw:
  30                 usage = GL_STREAM_DRAW;
  31                 break;
  32         case GraphicsBuffer::BufferUsageStreamRead:
  33                 usage = GL_STREAM_READ;
  34                 break;
  35         case GraphicsBuffer::BufferUsageStreamCopy:
  36                 usage = GL_STREAM_COPY;
  37                 break;
  38         default:
  39                 SDL_assert(false && "Unknown buffer usage type."); //WTF?
  40                 usage = GL_DYNAMIC_DRAW;
  41         }
  42         return usage;
  43 }
  44
  45 static GLenum BufferTypeToGLType(GraphicsBuffer::BufferType buffer_type)
  46 {
  47         switch (buffer_type)
  48         {
  49         case GraphicsBuffer::BufferTypeVertex:
  50                 return GL_ARRAY_BUFFER;
  51         case GraphicsBuffer::BufferTypeIndex:
  52                 return GL_ELEMENT_ARRAY_BUFFER;
  53         case GraphicsBuffer::BufferTypePixelPack:
  54                 return GL_PIXEL_PACK_BUFFER;
  55         case GraphicsBuffer::BufferTypePixelUnpack:
  56                 return GL_PIXEL_UNPACK_BUFFER;
  57         case GraphicsBuffer::BufferTypeUniform:
  58                 return GL_UNIFORM_BUFFER;
  59         case GraphicsBuffer::BufferTypeTexture:
  60                 return GL_TEXTURE_BUFFER;
  61         case GraphicsBuffer::BufferTypeDrawIndirect:
  62                 return GL_DRAW_INDIRECT_BUFFER;
  63         default:
  64                 return GL_COPY_READ_BUFFER;
  65         }
  66 }
  67
  68 GraphicsBuffer::GraphicsBuffer()
  69 {
  70         m_invalidated = true;
  71         m_map_pointer = NULL;
  72         m_buffer_size = 0;
  73         m_buffer_shape_dirty = true;
  74         m_buffer_handle = 0;
  75         m_buffer_usage = BufferUsageDynamicDraw;
  76         m_faking_map = false;
  77         SetUsage(BufferUsageStaticDraw);
  78 }
  79
  80 GraphicsBuffer::~GraphicsBuffer()
  81 {
  82         if (m_map_pointer)
  83         {
  84                 UnMap();
  85         }
  86         glDeleteBuffers(1, &m_buffer_handle);
  87 }
  88
  89 void GraphicsBuffer::SetType(GraphicsBuffer::BufferType bufType)
  90 {
  91         m_buffer_type = bufType;
  92 }
  93
  94 void GraphicsBuffer::SetUsage(GraphicsBuffer::BufferUsage bufUsage)
  95 {
  96         if (bufUsage != m_buffer_usage)
  97         {
  98                 m_buffer_usage = bufUsage;
  99                 m_buffer_shape_dirty = true;
 100         }
 101 }
 102
 103 void GraphicsBuffer::Invalidate()
 104 {
 105         m_invalidated = true;
 106         if (!m_buffer_shape_dirty)
 107         {
 108                 // Orphan the block of memory we're pointing to.
 109                 Upload(m_buffer_size, NULL);
 110         }
 111         // Apparently not supported.
 112         //glInvalidateBufferData(m_buffer_handle);
 113 }
 114
 115 bool GraphicsBuffer::RecreateBuffer(const void *data)
 116 {
 117         // If the buffer is not dirty, don't recreate it.
 118         if (!m_buffer_shape_dirty) return false;
 119         // If the buffer is mapped, don't recreate it.
 120         if (!m_faking_map && m_map_pointer) return false;
 121         // If the buffer has data in it we need, don't recreate it.
 122         if (!m_invalidated) return false;
 123         if (m_buffer_handle)
 124         {
 125                 glDeleteBuffers(1, &m_buffer_handle);
 126         }
 127         glGenBuffers(1, &m_buffer_handle);
 128         m_buffer_shape_dirty = false;
 129         if (m_buffer_size)
 130                 Upload(m_buffer_size, data);
 131         return true;
 132 }
 133
 134 void* GraphicsBuffer::Map(bool read, bool write, bool invalidate)
 135 {
 136         GLbitfield access = ((read)?GL_MAP_READ_BIT:0) | ((write)?GL_MAP_WRITE_BIT:0) | ((invalidate)?GL_MAP_INVALIDATE_BUFFER_BIT:0);
 137         GLenum target = BufferTypeToGLType(m_buffer_type);
 138
 139         if (invalidate)
 140         {
 141                 m_invalidated = true;
 142
 143                 // Intel's Mesa driver does not rename the buffer when we map with GL_MAP_INVALIDATE_BUFFER_BIT,
 144                 // resulting in the CPU stalling waiting for rendering from the buffer to complete on the GPU.
 145                 // We manually force the buffer to be renamed here to avoid this.
 146                 m_buffer_shape_dirty = true;
 147         }
 148
 149         if (m_map_pointer)
 150                 Warn("Tried to map already mapped buffer!");
 151
 152
 153         if (!read && m_buffer_usage == BufferUsage::BufferUsageStaticDraw)
 154         {
 155                 m_map_pointer = malloc(m_buffer_size);
 156                 m_faking_map = true;
 157                 return m_map_pointer;
 158         }
 159
 160         RecreateBuffer();
 161
 162         Bind();
 163
 164         m_map_pointer = glMapBufferRange(target, 0, m_buffer_size, access);
 165
 166         return m_map_pointer;
 167 }
 168
 169 void* GraphicsBuffer::MapRange(int offset, int length, bool read, bool write, bool invalidate)
 170 {
 171         GLbitfield access = ((read)?GL_MAP_READ_BIT:0) | ((write)?GL_MAP_WRITE_BIT:0) | ((invalidate)?GL_MAP_INVALIDATE_RANGE_BIT:0);
 172         GLenum target = BufferTypeToGLType(m_buffer_type);
 173
 174         if (m_map_pointer)
 175                 Warn("Tried to map already mapped buffer!");
 176
 177         RecreateBuffer();
 178
 179         Bind();
 180
 181         m_map_pointer = glMapBufferRange(target, offset, length, access);
 182         return m_map_pointer;
 183 }
 184
 185 void GraphicsBuffer::UnMap()
 186 {
 187         GLenum target = BufferTypeToGLType(m_buffer_type);
 188
 189         if (m_faking_map)
 190         {
 191                 Upload(m_buffer_size, m_map_pointer);
 192                 free(m_map_pointer);
 193                 m_map_pointer = nullptr;
 194                 m_invalidated = false;
 195                 m_faking_map = false;
 196                 return;
 197         }
 198
 199         Bind();
 200         glUnmapBuffer(target);
 201         m_map_pointer = nullptr;
 202         m_invalidated = false;
 203 }
 204
 205 void GraphicsBuffer::Upload(size_t length, const void* data)
 206 {
 207         GLenum target = BufferTypeToGLType(m_buffer_type);
 208
 209         GLenum usage = BufferUsageToGLUsage(m_buffer_usage);
 210
 211         m_invalidated = true;
 212         m_buffer_size = length;
 213         if (!RecreateBuffer(data))
 214         {
 215                 Bind();
 216                 glBufferData(target, length, data, usage);
 217         }
 218         if (data != nullptr)
 219                 m_invalidated = false;
 220 }
 221
 222 void GraphicsBuffer::UploadRange(size_t length, intptr_t offset, const void* data)
 223 {
 224         GLenum target = BufferTypeToGLType(m_buffer_type);
 225
 226         RecreateBuffer();
 227
 228         Bind();
 229         glBufferSubData(target, offset, length, data);
 230         m_invalidated = false;
 231 }
 232
 233 void GraphicsBuffer::Resize(size_t length)
 234 {
 235         if (m_invalidated)
 236         {
 237                 m_buffer_size = length;
 238         }
 239         else
 240         {
 241                 // Create a new buffer and copy the old data into it.
 242                 UnMap();
 243                 GLuint old_buffer = m_buffer_handle;
 244                 glGenBuffers(1, &m_buffer_handle);
 245                 Upload(length, nullptr);
 246                 glBindBuffer(GL_COPY_READ_BUFFER, old_buffer);
 247                 glBindBuffer(GL_COPY_WRITE_BUFFER, m_buffer_handle);
 248                 glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, 0, 0, m_buffer_size);
 249                 glDeleteBuffers(1, &old_buffer);
 250                 m_buffer_size = length;
 251         }
 252 }
 253
 254 void GraphicsBuffer::Bind() const
 255 {
 256         if (m_buffer_type == BufferTypeUniform)
 257                 glBindBufferBase(GL_UNIFORM_BUFFER, 0, m_buffer_handle);
 258         else
 259                 glBindBuffer(BufferTypeToGLType(m_buffer_type), m_buffer_handle);
 260 }
 261