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Replace buffer region implementation with GL3 renderbuffers
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This lets us enable partial region writes in the buffer region
interface, which is a huge performance boost for the dirty rectangle
system and gets us most of the way to DirectX-like framerates.
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@nsgomez
nsgomez committed Oct 17, 2023
1 parent 308fffb commit 034ec75
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Showing 6 changed files with 121 additions and 21 deletions.
22 changes: 22 additions & 0 deletions scgl/GLSupport.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,17 @@ PFNGLCLIENTACTIVETEXTUREPROC glClientActiveTexture = nullptr;
PFNGLGETSTRINGIPROC glGetStringi = nullptr;
PFNGLDEBUGMESSAGECALLBACKPROC glDebugMessageCallback = nullptr;

PFNGLBINDRENDERBUFFERPROC glBindRenderbuffer = nullptr;
PFNGLDELETERENDERBUFFERSPROC glDeleteRenderbuffers = nullptr;
PFNGLGENRENDERBUFFERSPROC glGenRenderbuffers = nullptr;
PFNGLRENDERBUFFERSTORAGEPROC glRenderbufferStorage = nullptr;
PFNGLBINDFRAMEBUFFERPROC glBindFramebuffer = nullptr;
PFNGLDELETEFRAMEBUFFERSPROC glDeleteFramebuffers = nullptr;
PFNGLGENFRAMEBUFFERSPROC glGenFramebuffers = nullptr;
PFNGLCHECKFRAMEBUFFERSTATUSPROC glCheckFramebufferStatus = nullptr;
PFNGLFRAMEBUFFERRENDERBUFFERPROC glFramebufferRenderbuffer = nullptr;
PFNGLBLITFRAMEBUFFERPROC glBlitFramebuffer = nullptr;

PFNWGLCREATEBUFFERREGIONARBPROC wglCreateBufferRegionARB = nullptr;
PFNWGLDELETEBUFFERREGIONARBPROC wglDeleteBufferRegionARB = nullptr;
PFNWGLSAVEBUFFERREGIONARBPROC wglSaveBufferRegionARB = nullptr;
Expand All @@ -32,6 +43,17 @@ void InitGLSupport(void) {
TRY_LOAD(PFNGLGETSTRINGIPROC, glGetStringi);
TRY_LOAD(PFNGLDEBUGMESSAGECALLBACKPROC, glDebugMessageCallback);

TRY_LOAD(PFNGLBINDRENDERBUFFERPROC, glBindRenderbuffer);
TRY_LOAD(PFNGLDELETERENDERBUFFERSPROC, glDeleteRenderbuffers);
TRY_LOAD(PFNGLGENRENDERBUFFERSPROC, glGenRenderbuffers);
TRY_LOAD(PFNGLRENDERBUFFERSTORAGEPROC, glRenderbufferStorage);
TRY_LOAD(PFNGLBINDFRAMEBUFFERPROC, glBindFramebuffer);
TRY_LOAD(PFNGLDELETEFRAMEBUFFERSPROC, glDeleteFramebuffers);
TRY_LOAD(PFNGLGENFRAMEBUFFERSPROC, glGenFramebuffers);
TRY_LOAD(PFNGLCHECKFRAMEBUFFERSTATUSPROC, glCheckFramebufferStatus);
TRY_LOAD(PFNGLFRAMEBUFFERRENDERBUFFERPROC, glFramebufferRenderbuffer);
TRY_LOAD(PFNGLBLITFRAMEBUFFERPROC, glBlitFramebuffer);

TRY_LOAD(PFNWGLCREATEBUFFERREGIONARBPROC, wglCreateBufferRegionARB);
TRY_LOAD(PFNWGLDELETEBUFFERREGIONARBPROC, wglDeleteBufferRegionARB);
TRY_LOAD(PFNWGLSAVEBUFFERREGIONARBPROC, wglSaveBufferRegionARB);
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37 changes: 37 additions & 0 deletions scgl/GLSupport.h
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Expand Up @@ -18,6 +18,17 @@ typedef void (APIENTRYP PFNGLCOMPRESSEDTEXSUBIMAGE2DPROC) (GLenum target, GLint
typedef void (APIENTRYP PFNGLACTIVETEXTUREPROC) (GLenum texture);
typedef void (APIENTRYP PFNGLCLIENTACTIVETEXTUREPROC) (GLenum texture);

typedef void (APIENTRYP PFNGLBINDRENDERBUFFERPROC) (GLenum target, GLuint renderbuffer);
typedef void (APIENTRYP PFNGLDELETERENDERBUFFERSPROC) (GLsizei n, const GLuint* renderbuffers);
typedef void (APIENTRYP PFNGLGENRENDERBUFFERSPROC) (GLsizei n, GLuint* renderbuffers);
typedef void (APIENTRYP PFNGLRENDERBUFFERSTORAGEPROC) (GLenum target, GLenum internalformat, GLsizei width, GLsizei height);
typedef void (APIENTRYP PFNGLBINDFRAMEBUFFERPROC) (GLenum target, GLuint framebuffer);
typedef void (APIENTRYP PFNGLDELETEFRAMEBUFFERSPROC) (GLsizei n, const GLuint* framebuffers);
typedef void (APIENTRYP PFNGLGENFRAMEBUFFERSPROC) (GLsizei n, GLuint* framebuffers);
typedef GLenum(APIENTRYP PFNGLCHECKFRAMEBUFFERSTATUSPROC) (GLenum target);
typedef void (APIENTRYP PFNGLFRAMEBUFFERRENDERBUFFERPROC) (GLenum target, GLenum attachment, GLenum renderbuffertarget, GLuint renderbuffer);
typedef void (APIENTRYP PFNGLBLITFRAMEBUFFERPROC) (GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter);

typedef const GLubyte* (APIENTRYP PFNGLGETSTRINGIPROC) (GLenum name, GLuint index);

typedef void (APIENTRY* GLDEBUGPROC)(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, const void* userParam);
Expand Down Expand Up @@ -78,6 +89,21 @@ typedef void (APIENTRYP PFNGLDEBUGMESSAGECALLBACKPROC) (GLDEBUGPROC callback, co
#define GL_OPERAND3_RGB_NV 0x8593
#define GL_OPERAND3_ALPHA_NV 0x859B

#define GL_RGB5_A1 0x8057
#define GL_RGBA8 0x8058
#define GL_DEPTH_COMPONENT16 0x81A5
#define GL_DEPTH_COMPONENT24 0x81A6
#define GL_DRAW_FRAMEBUFFER_BINDING 0x8CA6
#define GL_READ_FRAMEBUFFER 0x8CA8
#define GL_DRAW_FRAMEBUFFER 0x8CA9
#define GL_READ_FRAMEBUFFER_BINDING 0x8CAA
#define GL_COLOR_ATTACHMENT0 0x8CE0
#define GL_DEPTH_ATTACHMENT 0x8D00
#define GL_FRAMEBUFFER 0x8D40
#define GL_RENDERBUFFER 0x8D41
#define GL_FRAMEBUFFER_DEFAULT 0x8218
#define GL_FRAMEBUFFER_COMPLETE 0x8CD5

#define GL_DEBUG_OUTPUT_SYNCHRONOUS 0x8242
#define GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH 0x8243
#define GL_DEBUG_CALLBACK_FUNCTION 0x8244
Expand Down Expand Up @@ -209,6 +235,17 @@ extern PFNGLCLIENTACTIVETEXTUREPROC glClientActiveTexture;
extern PFNGLGETSTRINGIPROC glGetStringi;
extern PFNGLDEBUGMESSAGECALLBACKPROC glDebugMessageCallback;

extern PFNGLBINDRENDERBUFFERPROC glBindRenderbuffer;
extern PFNGLDELETERENDERBUFFERSPROC glDeleteRenderbuffers;
extern PFNGLGENRENDERBUFFERSPROC glGenRenderbuffers;
extern PFNGLRENDERBUFFERSTORAGEPROC glRenderbufferStorage;
extern PFNGLBINDFRAMEBUFFERPROC glBindFramebuffer;
extern PFNGLDELETEFRAMEBUFFERSPROC glDeleteFramebuffers;
extern PFNGLGENFRAMEBUFFERSPROC glGenFramebuffers;
extern PFNGLCHECKFRAMEBUFFERSTATUSPROC glCheckFramebufferStatus;
extern PFNGLFRAMEBUFFERRENDERBUFFERPROC glFramebufferRenderbuffer;
extern PFNGLBLITFRAMEBUFFERPROC glBlitFramebuffer;

extern PFNWGLCREATECONTEXTATTRIBSARBPROC wglCreateContextAttribsARB;
extern PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB;

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4 changes: 3 additions & 1 deletion scgl/cGDriver.cpp
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Expand Up @@ -31,7 +31,9 @@ namespace nSCGL
viewportWidth(0),
viewportHeight(0),
bufferRegionFlags(0),
bufferRegionHandles(),
framebufferHandles(),
renderbufferHandles(),
framebufferMasks(),
supportedExtensions(),
windowHandle(nullptr),
deviceContext(nullptr),
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4 changes: 3 additions & 1 deletion scgl/cGDriver.h
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Expand Up @@ -65,7 +65,9 @@ namespace nSCGL
// We're not expecting to use a lot of buffer regions simultaneously, so we'll use an
// 8-bit mask to indicate which regions are allocated and free.
uint8_t bufferRegionFlags;
void* bufferRegionHandles[MAX_BUFFER_REGIONS];
uint32_t framebufferHandles[MAX_BUFFER_REGIONS];
uint32_t renderbufferHandles[MAX_BUFFER_REGIONS];
uint32_t framebufferMasks[MAX_BUFFER_REGIONS];

private:
struct {
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4 changes: 2 additions & 2 deletions scgl/cGDriver_Viewport.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -163,7 +163,7 @@ namespace nSCGL
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cAlphaBits = (newMode.depth == 32) ? 8 : 1;
pfd.cColorBits = (newMode.depth == 32) ? 24 : 16;
pfd.cColorBits = (newMode.depth == 32) ? 24 : 15;
pfd.cDepthBits = (newMode.depth == 32) ? 24 : 16;
pfd.cStencilBits = 8;
pfd.iLayerType = PFD_MAIN_PLANE;
Expand Down Expand Up @@ -210,7 +210,7 @@ namespace nSCGL
wglMakeCurrent(hdc, static_cast<HGLRC>(glContext));

if (supportedExtensions.swapControl) {
wglSwapIntervalEXT(-1);
wglSwapIntervalEXT(0);
}

// Window should now be ready to go, show it and wrap up initialization
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71 changes: 54 additions & 17 deletions scgl/ext/cGDriver_BufferRegions.cpp
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Expand Up @@ -26,55 +26,92 @@ namespace nSCGL
}

uint32_t cGDriver::NewBufferRegion(int32_t gdBufferRegionType) {
static GLenum regionTypeMap[] = { WGL_BACK_COLOR_BUFFER_BIT_ARB, WGL_DEPTH_BUFFER_BIT_ARB, WGL_STENCIL_BUFFER_BIT_ARB };
static GLenum regionTypeMap[] = { WGL_BACK_COLOR_BUFFER_BIT_ARB, WGL_DEPTH_BUFFER_BIT_ARB };
SIZE_CHECK_RETVAL(gdBufferRegionType, regionTypeMap, 0);

if (!supportedExtensions.bufferRegion || wglCreateBufferRegionARB == nullptr) {
return 0;
}

uint32_t bufferRegionIndex = FindFreeBufferRegionIndex();
if (bufferRegionIndex == -1) {
return 0;
}

HANDLE result = wglCreateBufferRegionARB(reinterpret_cast<HDC>(deviceContext), 0, regionTypeMap[gdBufferRegionType]);
if (result == nullptr) {
GLuint framebuffer;
glGenFramebuffers(1, &framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);

GLuint renderbuffer;
glGenRenderbuffers(1, &renderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);

GLuint renderbufferStorageType, attachmentType;
GLuint framebufferMask;

if (regionTypeMap[gdBufferRegionType] == WGL_BACK_COLOR_BUFFER_BIT_ARB) {
renderbufferStorageType = (videoModes[currentVideoMode].depth == 32) ? GL_RGBA8 : GL_RGB5_A1;
attachmentType = GL_COLOR_ATTACHMENT0;
framebufferMask = GL_COLOR_BUFFER_BIT;
}
else {
renderbufferStorageType = (videoModes[currentVideoMode].depth == 32) ? GL_DEPTH_COMPONENT24 : GL_DEPTH_COMPONENT16;
attachmentType = GL_DEPTH_ATTACHMENT;
framebufferMask = GL_DEPTH_BUFFER_BIT;
}

glRenderbufferStorage(GL_RENDERBUFFER, renderbufferStorageType, windowWidth, windowHeight);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, attachmentType, GL_RENDERBUFFER, renderbuffer);

if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
return 0;
}

bufferRegionFlags |= 1 << bufferRegionIndex;
bufferRegionHandles[bufferRegionIndex] = result;
framebufferHandles[bufferRegionIndex] = framebuffer;
renderbufferHandles[bufferRegionIndex] = renderbuffer;
framebufferMasks[bufferRegionIndex] = framebufferMask;

glBindFramebuffer(GL_FRAMEBUFFER, 0);
return bufferRegionIndex + 1;
}

bool cGDriver::DeleteBufferRegion(int32_t region) {
uint32_t bufferRegionIndex = region - 1;
if ((bufferRegionFlags & (1 << bufferRegionIndex)) == 0) {
return true;
}

wglDeleteBufferRegionARB(bufferRegionHandles[bufferRegionIndex]);
bufferRegionHandles[bufferRegionIndex] = nullptr;
bufferRegionFlags &= ~(1 << bufferRegionIndex);
glDeleteRenderbuffers(1, &renderbufferHandles[bufferRegionIndex]);
glDeleteFramebuffers(1, &framebufferHandles[bufferRegionIndex]);

bufferRegionFlags &= ~(1 << bufferRegionIndex);
return true;
}

bool cGDriver::ReadBufferRegion(uint32_t region, GLint x, GLint y, GLsizei width, GLsizei height, int32_t unused0, int32_t unused1) {
return wglSaveBufferRegionARB(bufferRegionHandles[region - 1], x, y, width, height);
bool cGDriver::ReadBufferRegion(uint32_t region, GLint x0, GLint y0, GLsizei width, GLsizei height, int32_t unused0, int32_t unused1) {
uint32_t bufferRegionIndex = region - 1;
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, framebufferHandles[bufferRegionIndex]);

GLint x1 = x0 + width;
GLint y1 = y0 + height;

glBlitFramebuffer(x0, y0, x1, y1, x0, y0, x1, y1, framebufferMasks[bufferRegionIndex], GL_NEAREST);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
return true;
}

bool cGDriver::DrawBufferRegion(uint32_t region, GLint x, GLint y, GLsizei width, GLsizei height, GLint xDest, GLint yDest) {
return wglRestoreBufferRegionARB(bufferRegionHandles[region - 1], xDest, y, width, height, x, yDest);
uint32_t bufferRegionIndex = region - 1;
glBindFramebuffer(GL_READ_FRAMEBUFFER, framebufferHandles[bufferRegionIndex]);

glBlitFramebuffer(x, yDest, x + width, yDest + height, xDest, y, xDest + width, y + height, framebufferMasks[bufferRegionIndex], GL_NEAREST);
glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
return true;
}

bool cGDriver::IsBufferRegion(uint32_t region) {
return (bufferRegionFlags & (1 << (region - 1))) != 0;
}

bool cGDriver::CanDoPartialRegionWrites(void) {
// TODO: we might be able to implement partial writes if we use OpenGL 3.0 and glBlitFramebuffer
// instead of the older WGL_ARB_buffer_region extension.
return false;
return true;
}

bool cGDriver::CanDoOffsetReads(void) {
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