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.");
  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::BufferTypeDrawIndirect:
  60                 return GL_DRAW_INDIRECT_BUFFER;
  61         default:
  62                 return GL_COPY_READ_BUFFER;
  63         }
  64 }
  65
  66 GraphicsBuffer::GraphicsBuffer()
  67 {
  68         m_invalidated = true;
  69         m_map_pointer = nullptr;
  70         m_buffer_size = 0;
  71         m_buffer_shape_dirty = true;
  72         m_buffer_handle = 0;
  73         m_buffer_usage = BufferUsageDynamicDraw;
  74         SetUsage(BufferUsageStaticDraw);
  75 }
  76
  77 GraphicsBuffer::~GraphicsBuffer()
  78 {
  79         if (m_map_pointer)
  80         {
  81                 UnMap();
  82         }
  83         glDeleteBuffers(1, &m_buffer_handle);
  84 }
  85
  86 void GraphicsBuffer::SetType(GraphicsBuffer::BufferType bufType)
  87 {
  88         m_buffer_type = bufType;
  89 }
  90
  91 void GraphicsBuffer::SetUsage(GraphicsBuffer::BufferUsage bufUsage)
  92 {
  93         if (bufUsage != m_buffer_usage)
  94         {
  95                 m_buffer_usage = bufUsage;
  96                 m_buffer_shape_dirty = true;
  97         }
  98 }
  99
 100 void GraphicsBuffer::Invalidate()
 101 {
 102         m_invalidated = true;
 103         if (!m_buffer_shape_dirty)
 104         {
 105                 // Orphan the block of memory we're pointing to.
 106                 Upload(m_buffer_size, nullptr);
 107         }
 108         // Apparently not supported.
 109         //glInvalidateBufferData(m_buffer_handle);
 110 }
 111
 112 void GraphicsBuffer::RecreateBuffer()
 113 {
 114         // If the buffer is not dirty, don't recreate it.
 115         if (!m_buffer_shape_dirty) return;
 116         // If the buffer is mapped, don't recreate it.
 117         if (m_map_pointer) return;
 118         // If the buffer has data in it we need, don't recreate it.
 119         if (!m_invalidated) return;
 120         if (m_buffer_handle)
 121         {
 122                 glDeleteBuffers(1, &m_buffer_handle);
 123         }
 124         glGenBuffers(1, &m_buffer_handle);
 125         m_buffer_shape_dirty = false;
 126         if (m_buffer_size)
 127                 Upload(m_buffer_size, nullptr);
 128 }
 129
 130 void* GraphicsBuffer::Map(bool read, bool write, bool invalidate)
 131 {
 132         GLbitfield access = ((read)?GL_MAP_READ_BIT:0) | ((write)?GL_MAP_WRITE_BIT:0) | ((invalidate)?GL_MAP_INVALIDATE_BUFFER_BIT:0);
 133         GLenum target = BufferTypeToGLType(m_buffer_type);
 134
 135         if (invalidate)
 136         {
 137                 m_invalidated = true;
 138
 139                 // Intel's Mesa driver does not rename the buffer when we map with GL_MAP_INVALIDATE_BUFFER_BIT,
 140                 // resulting in the CPU stalling waiting for rendering from the buffer to complete on the GPU.
 141                 // We manually force the buffer to be renamed here to avoid this.
 142                 m_buffer_shape_dirty = true;
 143         }
 144
 145         if (m_map_pointer)
 146                 Warn("Tried to map already mapped buffer!");
 147
 148         RecreateBuffer();
 149
 150         Bind();
 151
 152         m_map_pointer = glMapBufferRange(target, 0, m_buffer_size, access);
 153
 154         return m_map_pointer;
 155 }
 156
 157 void* GraphicsBuffer::MapRange(int offset, int length, bool read, bool write, bool invalidate)
 158 {
 159         GLbitfield access = ((read)?GL_MAP_READ_BIT:0) | ((write)?GL_MAP_WRITE_BIT:0) | ((invalidate)?GL_MAP_INVALIDATE_RANGE_BIT:0);
 160         GLenum target = BufferTypeToGLType(m_buffer_type);
 161
 162         if (m_map_pointer)
 163                 Warn("Tried to map already mapped buffer!");
 164
 165         RecreateBuffer();
 166
 167         Bind();
 168
 169         m_map_pointer = glMapBufferRange(target, offset, length, access);
 170         return m_map_pointer;
 171 }
 172
 173 void GraphicsBuffer::UnMap()
 174 {
 175         GLenum target = BufferTypeToGLType(m_buffer_type);
 176
 177         Bind();
 178         glUnmapBuffer(target);
 179         m_map_pointer = nullptr;
 180         m_invalidated = false;
 181 }
 182
 183 void GraphicsBuffer::Upload(size_t length, const void* data)
 184 {
 185         GLenum target = BufferTypeToGLType(m_buffer_type);
 186
 187         GLenum usage = BufferUsageToGLUsage(m_buffer_usage);
 188
 189         m_invalidated = true;
 190         RecreateBuffer();
 191
 192         Bind();
 193         glBufferData(target, length, data, usage);
 194         if (data != nullptr)
 195                 m_invalidated = false;
 196         m_buffer_size = length;
 197 }
 198
 199 void GraphicsBuffer::UploadRange(size_t length, intptr_t offset, const void* data)
 200 {
 201         GLenum target = BufferTypeToGLType(m_buffer_type);
 202
 203         RecreateBuffer();
 204
 205         Bind();
 206         glBufferSubData(target, offset, length, data);
 207         m_invalidated = false;
 208 }
 209
 210 void GraphicsBuffer::Resize(size_t length)
 211 {
 212         if (m_invalidated)
 213         {
 214                 m_buffer_size = length;
 215                 RecreateBuffer();
 216         }
 217         else
 218         {
 219                 // Create a new buffer and copy the old data into it.
 220                 UnMap();
 221                 GLuint old_buffer = m_buffer_handle;
 222                 glGenBuffers(1, &m_buffer_handle);
 223                 Upload(length, nullptr);
 224                 glBindBuffer(GL_COPY_READ_BUFFER, old_buffer);
 225                 glBindBuffer(GL_COPY_WRITE_BUFFER, m_buffer_handle);
 226                 glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, 0, 0, m_buffer_size);
 227                 glDeleteBuffers(1, &old_buffer);
 228                 m_buffer_size = length;
 229         }
 230 }
 231
 232 void GraphicsBuffer::Bind() const
 233 {
 234         if (m_buffer_type == BufferTypeUniform)
 235                 glBindBufferBase(GL_UNIFORM_BUFFER, 0, m_buffer_handle);
 236         else
 237                 glBindBuffer(BufferTypeToGLType(m_buffer_type), m_buffer_handle);
 238 }
 239