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authorMichael Lutz <michi@icosahedron.de>2021-01-17 00:42:14 +0100
committerMichael Lutz <michi@icosahedron.de>2021-02-22 22:16:07 +0100
commit86c309ea75aecb47fc3b984462e07d62d0c70168 (patch)
treed1dc7033a7764ea9b08386aa035fa412f2396c88 /src
parent94d8acb7d007150606c0756060c6f0cf90ee7f70 (diff)
downloadopenttd-86c309ea75aecb47fc3b984462e07d62d0c70168.tar.xz
Codechange: [OpenGL] Let OpenGL clear the pixel buffer if possible.
Diffstat (limited to 'src')
-rw-r--r--src/video/opengl.cpp19
1 files changed, 15 insertions, 4 deletions
diff --git a/src/video/opengl.cpp b/src/video/opengl.cpp
index c795dcd60..87ce8b7f3 100644
--- a/src/video/opengl.cpp
+++ b/src/video/opengl.cpp
@@ -54,6 +54,7 @@ static PFNGLBINDBUFFERPROC _glBindBuffer;
static PFNGLBUFFERDATAPROC _glBufferData;
static PFNGLMAPBUFFERPROC _glMapBuffer;
static PFNGLUNMAPBUFFERPROC _glUnmapBuffer;
+static PFNGLCLEARBUFFERSUBDATAPROC _glClearBufferSubData;
static PFNGLBUFFERSTORAGEPROC _glBufferStorage;
static PFNGLMAPBUFFERRANGEPROC _glMapBufferRange;
@@ -209,6 +210,12 @@ static bool BindVBOExtension()
_glUnmapBuffer = (PFNGLUNMAPBUFFERPROC)GetOGLProcAddress("glUnmapBufferARB");
}
+ if (IsOpenGLVersionAtLeast(4, 3) || IsOpenGLExtensionSupported("GL_ARB_clear_buffer_object")) {
+ _glClearBufferSubData = (PFNGLCLEARBUFFERSUBDATAPROC)GetOGLProcAddress("glClearBufferSubData");
+ } else {
+ _glClearBufferSubData = nullptr;
+ }
+
return _glGenBuffers != nullptr && _glDeleteBuffers != nullptr && _glBindBuffer != nullptr && _glBufferData != nullptr && _glMapBuffer != nullptr && _glUnmapBuffer != nullptr;
}
@@ -776,11 +783,15 @@ bool OpenGLBackend::Resize(int w, int h, bool force)
if (bpp == 32) {
/* Initialize backing store alpha to opaque for 32bpp modes. */
Colour black(0, 0, 0);
- uint32 *buf = (uint32 *)_glMapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_READ_WRITE);
- for (int i = 0; i < pitch * h; i++) {
- *buf++ = black.data;
+ if (_glClearBufferSubData != nullptr) {
+ _glClearBufferSubData(GL_PIXEL_UNPACK_BUFFER, GL_RGBA8, 0, pitch * h * bpp / 8, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, &black.data);
+ } else {
+ uint32 *buf = (uint32 *)_glMapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_READ_WRITE);
+ for (int i = 0; i < pitch * h; i++) {
+ *buf++ = black.data;
+ }
+ _glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
}
- _glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
}
_glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);