1 #include "graphicsbuffer.h"
6 static GLenum BufferUsageToGLUsage(GraphicsBuffer::BufferUsage buffer_usage)
11 case GraphicsBuffer::BufferUsageStaticDraw:
12 usage = GL_STATIC_DRAW;
14 case GraphicsBuffer::BufferUsageStaticRead:
15 usage = GL_STATIC_READ;
17 case GraphicsBuffer::BufferUsageStaticCopy:
18 usage = GL_STATIC_COPY;
20 case GraphicsBuffer::BufferUsageDynamicDraw:
21 usage = GL_DYNAMIC_DRAW;
23 case GraphicsBuffer::BufferUsageDynamicRead:
24 usage = GL_DYNAMIC_READ;
26 case GraphicsBuffer::BufferUsageDynamicCopy:
27 usage = GL_DYNAMIC_COPY;
29 case GraphicsBuffer::BufferUsageStreamDraw:
30 usage = GL_STREAM_DRAW;
32 case GraphicsBuffer::BufferUsageStreamRead:
33 usage = GL_STREAM_READ;
35 case GraphicsBuffer::BufferUsageStreamCopy:
36 usage = GL_STREAM_COPY;
39 SDL_assert(false && "Unknown buffer usage type.");
40 usage = GL_DYNAMIC_DRAW;
45 static GLenum BufferTypeToGLType(GraphicsBuffer::BufferType buffer_type)
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;
62 return GL_COPY_READ_BUFFER;
66 GraphicsBuffer::GraphicsBuffer()
69 m_map_pointer = nullptr;
71 m_buffer_shape_dirty = true;
73 m_buffer_usage = BufferUsageDynamicDraw;
74 SetUsage(BufferUsageStaticDraw);
77 GraphicsBuffer::~GraphicsBuffer()
83 glDeleteBuffers(1, &m_buffer_handle);
86 void GraphicsBuffer::SetType(GraphicsBuffer::BufferType bufType)
88 m_buffer_type = bufType;
91 void GraphicsBuffer::SetUsage(GraphicsBuffer::BufferUsage bufUsage)
93 if (bufUsage != m_buffer_usage)
95 m_buffer_usage = bufUsage;
96 m_buffer_shape_dirty = true;
100 void GraphicsBuffer::Invalidate()
102 m_invalidated = true;
103 if (!m_buffer_shape_dirty)
105 // Orphan the block of memory we're pointing to.
106 Upload(m_buffer_size, nullptr);
108 // Apparently not supported.
109 //glInvalidateBufferData(m_buffer_handle);
112 void GraphicsBuffer::RecreateBuffer()
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;
122 glDeleteBuffers(1, &m_buffer_handle);
124 glGenBuffers(1, &m_buffer_handle);
125 m_buffer_shape_dirty = false;
127 Upload(m_buffer_size, nullptr);
130 void* GraphicsBuffer::Map(bool read, bool write, bool invalidate)
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);
137 m_invalidated = true;
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;
146 Warn("Tried to map already mapped buffer!");
152 m_map_pointer = glMapBufferRange(target, 0, m_buffer_size, access);
154 return m_map_pointer;
157 void* GraphicsBuffer::MapRange(int offset, int length, bool read, bool write, bool invalidate)
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);
163 Warn("Tried to map already mapped buffer!");
169 m_map_pointer = glMapBufferRange(target, offset, length, access);
170 return m_map_pointer;
173 void GraphicsBuffer::UnMap()
175 GLenum target = BufferTypeToGLType(m_buffer_type);
178 glUnmapBuffer(target);
179 m_map_pointer = nullptr;
180 m_invalidated = false;
183 void GraphicsBuffer::Upload(size_t length, const void* data)
185 GLenum target = BufferTypeToGLType(m_buffer_type);
187 GLenum usage = BufferUsageToGLUsage(m_buffer_usage);
189 m_invalidated = true;
193 glBufferData(target, length, data, usage);
195 m_invalidated = false;
196 m_buffer_size = length;
199 void GraphicsBuffer::UploadRange(size_t length, intptr_t offset, const void* data)
201 GLenum target = BufferTypeToGLType(m_buffer_type);
206 glBufferSubData(target, offset, length, data);
207 m_invalidated = false;
210 void GraphicsBuffer::Resize(size_t length)
214 m_buffer_size = length;
219 // Create a new buffer and copy the old data into it.
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;
232 void GraphicsBuffer::Bind() const
234 if (m_buffer_type == BufferTypeUniform)
235 glBindBufferBase(GL_UNIFORM_BUFFER, 0, m_buffer_handle);
237 glBindBuffer(BufferTypeToGLType(m_buffer_type), m_buffer_handle);