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authorMichael Lutz <michi@icosahedron.de>2021-01-16 16:43:16 +0100
committerMichael Lutz <michi@icosahedron.de>2021-02-22 22:16:07 +0100
commita990c497b5dfbb51f8196a874eb4cb29b4933328 (patch)
treebd30a881f5ac0315c5bcfebd0c935bbbd338d24f
parent5af0cfd902e71d1d3ed5d20649b44f5c0125b4cd (diff)
downloadopenttd-a990c497b5dfbb51f8196a874eb4cb29b4933328.tar.xz
Codechange: [OpenGL] Use a pixel buffer object to store the video buffer.
-rw-r--r--src/video/opengl.cpp58
-rw-r--r--src/video/opengl.h11
-rw-r--r--src/video/win32_v.cpp46
-rw-r--r--src/video/win32_v.h5
4 files changed, 87 insertions, 33 deletions
diff --git a/src/video/opengl.cpp b/src/video/opengl.cpp
index 6f329994f..cbad8a167 100644
--- a/src/video/opengl.cpp
+++ b/src/video/opengl.cpp
@@ -264,9 +264,9 @@ OpenGLBackend::~OpenGLBackend()
if (_glDeleteVertexArrays != nullptr) _glDeleteVertexArrays(1, &this->vao_quad);
if (_glDeleteBuffers != nullptr) {
_glDeleteBuffers(1, &this->vbo_quad);
+ _glDeleteBuffers(1, &this->vid_pbo);
}
glDeleteTextures(1, &this->vid_texture);
- free(this->vid_buffer);
}
/**
@@ -297,6 +297,8 @@ const char *OpenGLBackend::Init()
/* Check for vertex buffer objects. */
if (!IsOpenGLVersionAtLeast(1, 5) && !IsOpenGLExtensionSupported("ARB_vertex_buffer_object")) return "Vertex buffer objects not supported";
if (!BindVBOExtension()) return "Failed to bind VBO extension functions";
+ /* Check for pixel buffer objects. */
+ if (!IsOpenGLVersionAtLeast(2, 1) && !IsOpenGLExtensionSupported("GL_ARB_pixel_buffer_object")) return "Pixel buffer objects not supported";
/* Check for vertex array objects. */
if (!IsOpenGLVersionAtLeast(3, 0) && (!IsOpenGLExtensionSupported("GL_ARB_vertex_array_object") || !IsOpenGLExtensionSupported("GL_APPLE_vertex_array_object"))) return "Vertex array objects not supported";
if (!BindVBAExtension()) return "Failed to bind VBA extension functions";
@@ -312,6 +314,11 @@ const char *OpenGLBackend::Init()
glBindTexture(GL_TEXTURE_2D, 0);
if (glGetError() != GL_NO_ERROR) return "Can't generate video buffer texture";
+ /* Create pixel buffer object as video buffer storage. */
+ _glGenBuffers(1, &this->vid_pbo);
+ _glBindBuffer(GL_PIXEL_UNPACK_BUFFER, this->vid_pbo);
+ if (glGetError() != GL_NO_ERROR) return "Can't allocate pixel buffer for video buffer";
+
/* Prime vertex buffer with a full-screen quad and store
* the corresponding state in a vertex array object. */
static const Simple2DVertex vert_array[] = {
@@ -355,13 +362,14 @@ const char *OpenGLBackend::Init()
*/
bool OpenGLBackend::Resize(int w, int h, bool force)
{
- if (!force && _screen.width == w && _screen.height == h && this->vid_buffer != nullptr) return false;
+ if (!force && _screen.width == w && _screen.height == h) return false;
glViewport(0, 0, w, h);
- /* Re-allocate video buffer texture. */
- free(this->vid_buffer);
- this->vid_buffer = CallocT<uint32>(w * h); // 32bpp
+ /* Re-allocate video buffer texture and backing store. */
+ _glBindBuffer(GL_PIXEL_UNPACK_BUFFER, this->vid_pbo);
+ _glBufferData(GL_PIXEL_UNPACK_BUFFER, w * h * 4, nullptr, GL_DYNAMIC_READ); // Buffer content has to persist from frame to frame and is read back by the blitter, which means a READ usage hint.
+ _glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
glBindTexture(GL_TEXTURE_2D, this->vid_texture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, w, h, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, nullptr);
@@ -371,30 +379,50 @@ bool OpenGLBackend::Resize(int w, int h, bool force)
_screen.height = h;
_screen.width = w;
_screen.pitch = w;
- _screen.dst_ptr = this->GetVideoBuffer();
+ _screen.dst_ptr = nullptr;
return true;
}
/**
* Render video buffer to the screen.
+ */
+void OpenGLBackend::Paint()
+{
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ /* Blit video buffer to screen. */
+ glBindTexture(GL_TEXTURE_2D, this->vid_texture);
+ _glBindVertexArray(this->vao_quad);
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+}
+
+/**
+ * Get a pointer to the memory for the video driver to draw to.
+ * @return Pointer to draw on.
+ */
+void *OpenGLBackend::GetVideoBuffer()
+{
+ _glBindBuffer(GL_PIXEL_UNPACK_BUFFER, this->vid_pbo);
+ return _glMapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_READ_WRITE);
+}
+
+/**
+ * Update video buffer texture after the video buffer was filled.
* @param update_rect Rectangle encompassing the dirty region of the video buffer.
*/
-void OpenGLBackend::Paint(Rect update_rect)
+void OpenGLBackend::ReleaseVideoBuffer(const Rect &update_rect)
{
- assert(this->vid_buffer != nullptr);
+ assert(this->vid_pbo != 0);
- glClear(GL_COLOR_BUFFER_BIT);
+ _glBindBuffer(GL_PIXEL_UNPACK_BUFFER, this->vid_pbo);
+ _glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
/* Update changed rect of the video buffer texture. */
- glBindTexture(GL_TEXTURE_2D, this->vid_texture);
if (!IsEmptyRect(update_rect)) {
+ glBindTexture(GL_TEXTURE_2D, this->vid_texture);
glPixelStorei(GL_UNPACK_ROW_LENGTH, _screen.pitch);
- glTexSubImage2D(GL_TEXTURE_2D, 0, update_rect.left, update_rect.top, update_rect.right - update_rect.left, update_rect.bottom - update_rect.top, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, (uint32 *)this->vid_buffer + update_rect.top * _screen.pitch + update_rect.left);
+ glTexSubImage2D(GL_TEXTURE_2D, 0, update_rect.left, update_rect.top, update_rect.right - update_rect.left, update_rect.bottom - update_rect.top, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, (GLvoid *)(size_t)(update_rect.top * _screen.pitch * 4 + update_rect.left * 4));
}
-
- /* Blit video buffer to screen. */
- _glBindVertexArray(this->vao_quad);
- glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
diff --git a/src/video/opengl.h b/src/video/opengl.h
index dfc71b5f7..16d72ff87 100644
--- a/src/video/opengl.h
+++ b/src/video/opengl.h
@@ -25,7 +25,7 @@ class OpenGLBackend : public ZeroedMemoryAllocator {
private:
static OpenGLBackend *instance; ///< Singleton instance pointer.
- void *vid_buffer; ///< Pointer to the memory used for the video driver to draw to.
+ GLuint vid_pbo; ///< Pixel buffer object storing the memory used for the video driver to draw to.
GLuint vid_texture; ///< Texture handle for the video buffer texture.
GLuint vao_quad; ///< Vertex array object storing the rendering state for the fullscreen quad.
GLuint vbo_quad; ///< Vertex buffer with a fullscreen quad.
@@ -45,13 +45,10 @@ public:
static void Destroy();
bool Resize(int w, int h, bool force = false);
- void Paint(Rect update_rect);
+ void Paint();
- /**
- * Get a pointer to the memory for the video driver to draw to.
- * @return Pointer to draw on.
- */
- void *GetVideoBuffer() { return this->vid_buffer; }
+ void *GetVideoBuffer();
+ void ReleaseVideoBuffer(const Rect &update_rect);
};
#endif /* VIDEO_OPENGL_H */
diff --git a/src/video/win32_v.cpp b/src/video/win32_v.cpp
index 0e0f50b61..7c1cae8f6 100644
--- a/src/video/win32_v.cpp
+++ b/src/video/win32_v.cpp
@@ -984,10 +984,10 @@ void VideoDriver_Win32Base::MainLoop()
}
}
-void VideoDriver_Win32Base::ClientSizeChanged(int w, int h)
+void VideoDriver_Win32Base::ClientSizeChanged(int w, int h, bool force)
{
/* Allocate backing store of the new size. */
- if (this->AllocateBackingStore(w, h)) {
+ if (this->AllocateBackingStore(w, h, force)) {
/* Mark all palette colours dirty. */
_cur_palette.first_dirty = 0;
_cur_palette.count_dirty = 256;
@@ -1093,12 +1093,20 @@ bool VideoDriver_Win32Base::LockVideoBuffer()
if (this->draw_threaded) this->draw_lock.lock();
_screen.dst_ptr = this->GetVideoPointer();
+ assert(_screen.dst_ptr != nullptr);
return true;
}
void VideoDriver_Win32Base::UnlockVideoBuffer()
{
+ assert(_screen.dst_ptr != nullptr);
+ if (_screen.dst_ptr != nullptr) {
+ /* Hand video buffer back to the drawing backend. */
+ this->ReleaseVideoPointer();
+ _screen.dst_ptr = nullptr;
+ }
+
if (this->draw_threaded) this->draw_lock.unlock();
this->buffer_locked = false;
}
@@ -1239,9 +1247,16 @@ void VideoDriver_Win32GDI::Paint()
this->UpdatePalette(dc2, _local_palette.first_dirty, _local_palette.count_dirty);
break;
- case Blitter::PALETTE_ANIMATION_BLITTER:
+ case Blitter::PALETTE_ANIMATION_BLITTER: {
+ bool need_buf = _screen.dst_ptr == nullptr;
+ if (need_buf) _screen.dst_ptr = this->GetVideoPointer();
blitter->PaletteAnimate(_local_palette);
+ if (need_buf) {
+ this->ReleaseVideoPointer();
+ _screen.dst_ptr = nullptr;
+ }
break;
+ }
case Blitter::PALETTE_ANIMATION_NONE:
break;
@@ -1336,7 +1351,7 @@ const char *VideoDriver_Win32OpenGL::Start(const StringList &param)
return err;
}
- this->ClientSizeChanged(this->width, this->height);
+ this->ClientSizeChanged(this->width, this->height, true);
this->draw_threaded = false;
MarkWholeScreenDirty();
@@ -1403,17 +1418,18 @@ const char *VideoDriver_Win32OpenGL::AllocateContext()
bool VideoDriver_Win32OpenGL::ToggleFullscreen(bool full_screen)
{
+ if (_screen.dst_ptr != nullptr) this->ReleaseVideoPointer();
this->DestroyContext();
bool res = this->VideoDriver_Win32Base::ToggleFullscreen(full_screen);
res &= this->AllocateContext() == nullptr;
- this->ClientSizeChanged(this->width, this->height);
+ this->ClientSizeChanged(this->width, this->height, true);
return res;
}
bool VideoDriver_Win32OpenGL::AfterBlitterChange()
{
assert(BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 0);
- this->ClientSizeChanged(this->width, this->height);
+ this->ClientSizeChanged(this->width, this->height, true);
return true;
}
@@ -1426,8 +1442,13 @@ bool VideoDriver_Win32OpenGL::AllocateBackingStore(int w, int h, bool force)
if (this->gl_rc == nullptr) return false;
+ if (_screen.dst_ptr != nullptr) this->ReleaseVideoPointer();
+
this->dirty_rect = {};
- return OpenGLBackend::Get()->Resize(w, h, force);
+ bool res = OpenGLBackend::Get()->Resize(w, h, force);
+ _screen.dst_ptr = this->GetVideoPointer();
+
+ return res;
}
void *VideoDriver_Win32OpenGL::GetVideoPointer()
@@ -1435,6 +1456,13 @@ void *VideoDriver_Win32OpenGL::GetVideoPointer()
return OpenGLBackend::Get()->GetVideoBuffer();
}
+void VideoDriver_Win32OpenGL::ReleaseVideoPointer()
+{
+ OpenGLBackend::Get()->ReleaseVideoBuffer(this->dirty_rect);
+ this->dirty_rect = {};
+ _screen.dst_ptr = nullptr;
+}
+
void VideoDriver_Win32OpenGL::Paint()
{
PerformanceMeasurer framerate(PFE_VIDEO);
@@ -1459,10 +1487,8 @@ void VideoDriver_Win32OpenGL::Paint()
_cur_palette.count_dirty = 0;
}
- OpenGLBackend::Get()->Paint(this->dirty_rect);
+ OpenGLBackend::Get()->Paint();
SwapBuffers(this->dc);
-
- this->dirty_rect = {};
}
#endif /* WITH_OPENGL */
diff --git a/src/video/win32_v.h b/src/video/win32_v.h
index 85ac153bf..061f39c0a 100644
--- a/src/video/win32_v.h
+++ b/src/video/win32_v.h
@@ -63,7 +63,7 @@ protected:
void Initialize();
bool MakeWindow(bool full_screen);
- void ClientSizeChanged(int w, int h);
+ void ClientSizeChanged(int w, int h, bool force = false);
/** Get screen depth to use for fullscreen mode. */
virtual uint8 GetFullscreenBpp();
@@ -71,6 +71,8 @@ protected:
virtual bool AllocateBackingStore(int w, int h, bool force = false) = 0;
/** Get a pointer to the video buffer. */
virtual void *GetVideoPointer() = 0;
+ /** Hand video buffer back to the painting backend. */
+ virtual void ReleaseVideoPointer() {}
/** Palette of the window has changed. */
virtual void PaletteChanged(HWND hWnd) = 0;
@@ -149,6 +151,7 @@ protected:
bool AllocateBackingStore(int w, int h, bool force = false) override;
void *GetVideoPointer() override;
+ void ReleaseVideoPointer() override;
void PaletteChanged(HWND hWnd) override {}
const char *AllocateContext();