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@roxlu roxlu/AsyncUpload.cpp
Last active Apr 26, 2019

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Experimental code to test fast pixel transfers using PBOs.
#include <gfx/AsyncUpload.h>
namespace gfx {
AsyncUpload::AsyncUpload()
:width(0)
,height(0)
,dx(0)
,channels(0)
,n(0)
{
}
AsyncUpload::~AsyncUpload() {
shutdown();
}
int AsyncUpload::init(int w, int h, GLenum fmt) {
if (0 == w) {
RX_ERROR("Width is 0.");
return -1;
}
if (0 == h) {
RX_ERROR("Height is 0.");
return -2;
}
if (0 != width) {
RX_ERROR("The width is not 0, did you call shutdown?");
return -3;
}
if (fmt == GL_RGBA || fmt == GL_RGBA8) {
format = GL_RGBA;
channels = 4;
}
else if (fmt == GL_RGB || fmt == GL_RGB8) {
format = GL_RGB;
channels = 3;
}
else {
RX_ERROR("Format is not GL_RGBA, GL_RGBA8, GL_RGB, GL_RGB8; for now only GL_RGBA, GL_RGB are supported.");
return -4;
}
width = w;
height = h;
format = fmt;
dx = 0;
nbytes = width * height * channels;
glGenBuffers(ASYNC_UPLOAD_NUM_BUFFERS, pbo);
for (int i = 0; i < ASYNC_UPLOAD_NUM_BUFFERS; ++i) {
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo[i]);
glBufferData(GL_PIXEL_UNPACK_BUFFER, nbytes, NULL, GL_STREAM_DRAW);
}
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
RX_VERBOSE("Created %d pixel unpack buffers that can hold %d bytes", ASYNC_UPLOAD_NUM_BUFFERS, nbytes);
return 0;
}
int AsyncUpload::upload(unsigned char* pixels) {
if (0 == width || 0 == height || 0 == channels) {
RX_ERROR("Trying to upload pixels; but it looks like we're not yet initialized.");
return -1;
}
if (NULL == pixels) {
RX_ERROR("Invalid pixels given; NULL");
return -2;
}
#if 1
/* fast upload */
dx = n % ASYNC_UPLOAD_NUM_BUFFERS;
if (n < ASYNC_UPLOAD_NUM_BUFFERS) {
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo[dx]);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, NULL);
}
else {
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo[dx]);
GLubyte* ptr = (GLubyte*)glMapBuffer(GL_PIXEL_UNPACK_BUFFER, GL_WRITE_ONLY);
if (NULL != ptr) {
memcpy(ptr, pixels, nbytes); /* takes about 0.0039 seconds for 1920 x 1200 rgba buffer */
glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, NULL);
}
}
++n;
#else
/* non-optimal upload */
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, pixels);
#endif
return 0;
}
int AsyncUpload::shutdown() {
if (0 != width) {
RX_ERROR("Cannot shutdown as width is 0. Did you init?");
return -1;
}
glDeleteBuffers(ASYNC_UPLOAD_NUM_BUFFERS, pbo);
width = 0;
height = 0;
dx = 0;
channels = 0;
n = 0;
return 0;
}
} /* namespace gfx */
/*
---------------------------------------------------------------------------------
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www.roxlu.com
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www.twitter.com/roxlu
---------------------------------------------------------------------------------
AsyncUpload
------------
This class uses a couple of pixel buffer objects to overcome
synchronization issues when uploading data to the gpu. It's build for
a specific project where we had to upload the complete pixel buffer.
Make sure that you use GL_BGRA as format with GL_UNSIGNED_INT_8_8_8_8_REV
as type for the texture that you're using (on mac). When you use only 3
channel images, you won't get the optimal upload path and performance is
extremelly reduced.
Use something like:
--
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, NULL);
--
*/
#ifndef ASYNC_UPLOAD_H
#define ASYNC_UPLOAD_H
#include <stdint.h>
#include <glad/glad.h>
#define ROXLU_USE_LOG
#define ROXLU_USE_OPENGL
#define ROXLU_USE_MATH
#include <tinylib.h>
#define ASYNC_UPLOAD_NUM_BUFFERS 3
namespace gfx {
class AsyncUpload {
public:
AsyncUpload();
~AsyncUpload();
int init(int w, int h, GLenum fmt); /* allocates memory; creates GL objects. */
int shutdown(); /* frees all memory; destroys GL objects. */
int upload(unsigned char* pixels); /* upload the given pixels, we assume that you have bound a texture of the same dimensions as our buffers */
public:
GLuint pbo[ASYNC_UPLOAD_NUM_BUFFERS]; /* the pbos that are created in init(), and removed in shutdown(). */
GLenum format; /* what format is used */
int dx; /* current index into the pbo array */
int width; /* width of the texture */
int height; /* height of the texture */
int nbytes; /* number of bytes in the PBOs */
int channels; /* number of color channels that are used */
uint64_t n; /* number of uploads, used to 'schedule' what PBO we should use. */
};
} /* namespace gfx */
#endif
With 3 PBOs, format GL_BGRA, type: GL_UNSIGNED_INT_8_8_8_8_REV
-------------------------------------------------------------------
2014.08.28_09.56.55_609: verbose [int main():162] = Took: 0.003976
2014.08.28_09.56.55_623: verbose [int main():162] = Took: 0.003766
2014.08.28_09.56.56_658: verbose [int main():162] = Took: 0.004171
2014.08.28_09.56.56_665: verbose [int main():162] = Took: 0.005319
2014.08.28_09.56.56_673: verbose [int main():162] = Took: 0.003831
2014.08.28_09.56.56_690: verbose [int main():162] = Took: 0.004001
2014.08.28_09.56.56_716: verbose [int main():162] = Took: 0.005537
2014.08.28_09.56.56_726: verbose [int main():162] = Took: 0.003836
2014.08.28_09.56.56_739: verbose [int main():162] = Took: 0.003944
2014.08.28_09.56.56_776: verbose [int main():162] = Took: 0.004286
2014.08.28_09.56.56_783: verbose [int main():162] = Took: 0.005428
2014.08.28_09.56.56_790: verbose [int main():162] = Took: 0.004276
2014.08.28_09.56.56_808: verbose [int main():162] = Took: 0.004208
2014.08.28_09.56.56_833: verbose [int main():162] = Took: 0.005733
2014.08.28_09.56.56_843: verbose [int main():162] = Took: 0.003975
2014.08.28_09.56.56_857: verbose [int main():162] = Took: 0.003847
2014.08.28_09.56.56_892: verbose [int main():162] = Took: 0.004260
2014.08.28_09.56.56_898: verbose [int main():162] = Took: 0.004506
2014.08.28_09.56.56_907: verbose [int main():162] = Took: 0.003997
2014.08.28_09.56.56_924: verbose [int main():162] = Took: 0.003954
2014.08.28_09.56.56_948: verbose [int main():162] = Took: 0.004570
2014.08.28_09.56.56_962: verbose [int main():162] = Took: 0.003556
2014.08.28_09.56.56_975: verbose [int main():162] = Took: 0.004052
2014.08.28_09.56.56_14: verbose [int main():162] = Took: 0.015949
2014.08.28_09.56.56_48: verbose [int main():162] = Took: 0.032679
2014.08.28_09.56.56_61: verbose [int main():162] = Took: 0.005951
2014.08.28_09.56.56_75: verbose [int main():162] = Took: 0.003924
2014.08.28_09.56.56_88: verbose [int main():162] = Took: 0.011031
2014.08.28_09.56.56_100: verbose [int main():162] = Took: 0.004205
2014.08.28_09.56.56_122: verbose [int main():162] = Took: 0.004896
2014.08.28_09.56.56_149: verbose [int main():162] = Took: 0.004883
2014.08.28_09.56.56_173: verbose [int main():162] = Took: 0.004348
2014.08.28_09.56.56_201: verbose [int main():162] = Took: 0.006323
2014.08.28_09.56.56_224: verbose [int main():162] = Took: 0.003962
2014.08.28_09.56.56_270: verbose [int main():162] = Took: 0.004066
2014.08.28_09.56.56_290: verbose [int main():162] = Took: 0.005125
2014.08.28_09.56.56_312: verbose [int main():162] = Took: 0.007200
2014.08.28_09.56.56_346: verbose [int main():162] = Took: 0.003861
2014.08.28_09.56.56_361: verbose [int main():162] = Took: 0.003996
2014.08.28_09.56.56_399: verbose [int main():162] = Took: 0.004490
2014.08.28_09.56.56_411: verbose [int main():162] = Took: 0.003905
2014.08.28_09.56.56_449: verbose [int main():162] = Took: 0.004929
2014.08.28_09.56.56_472: verbose [int main():162] = Took: 0.004919
2014.08.28_09.56.56_504: verbose [int main():162] = Took: 0.004780
2014.08.28_09.56.56_524: verbose [int main():162] = Took: 0.004283
2014.08.28_09.56.56_572: verbose [int main():162] = Took: 0.003920
2014.08.28_09.56.56_606: verbose [int main():162] = Took: 0.004039
2014.08.28_09.56.57_656: verbose [int main():162] = Took: 0.004160
2014.08.28_09.56.57_687: verbose [int main():162] = Took: 0.003985
2014.08.28_09.56.57_720: verbose [int main():162] = Took: 0.005126
2014.08.28_09.56.57_740: verbose [int main():162] = Took: 0.004966
2014.08.28_09.56.57_780: verbose [int main():162] = Took: 0.004602
2014.08.28_09.56.57_796: verbose [int main():162] = Took: 0.003868
2014.08.28_09.56.57_834: verbose [int main():162] = Took: 0.004571
2014.08.28_09.56.57_845: verbose [int main():162] = Took: 0.003883
2014.08.28_09.56.57_876: verbose [int main():162] = Took: 0.007581
2014.08.28_09.56.57_896: verbose [int main():162] = Took: 0.004338
2014.08.28_09.56.57_931: verbose [int main():162] = Took: 0.004243
2014.08.28_09.56.57_946: verbose [int main():162] = Took: 0.003892
2014.08.28_09.56.57_973: verbose [int main():162] = Took: 0.003840
2014.08.28_09.56.57_24: verbose [int main():162] = Took: 0.004088
2014.08.28_09.56.57_55: verbose [int main():162] = Took: 0.003907
2014.08.28_09.56.57_88: verbose [int main():162] = Took: 0.003831
2014.08.28_09.56.57_108: verbose [int main():162] = Took: 0.005098
2014.08.28_09.56.57_152: verbose [int main():162] = Took: 0.004121
2014.08.28_09.56.57_164: verbose [int main():162] = Took: 0.003935
2014.08.28_09.56.57_206: verbose [int main():162] = Took: 0.004132
2014.08.28_09.56.57_216: verbose [int main():162] = Took: 0.004512
2014.08.28_09.56.57_241: verbose [int main():162] = Took: 0.004029
2014.08.28_09.56.57_280: verbose [int main():162] = Took: 0.003882
2014.08.28_09.56.57_296: verbose [int main():162] = Took: 0.003888
2014.08.28_09.56.57_311: verbose [int main():162] = Took: 0.003840
2014.08.28_09.56.57_335: verbose [int main():162] = Took: 0.005672
2014.08.28_09.56.57_362: verbose [int main():162] = Took: 0.004059
2014.08.28_09.56.57_391: verbose [int main():162] = Took: 0.003849
2014.08.28_09.56.57_411: verbose [int main():162] = Took: 0.003838
Using glTexSubImage2D w/o PBOs. Same format as above.
-------------------------------------------------------------------
2014.08.28_09.57.33_227: verbose [int main():162] = Took: 0.015712
2014.08.28_09.57.33_259: verbose [int main():162] = Took: 0.020895
2014.08.28_09.57.33_283: verbose [int main():162] = Took: 0.021503
2014.08.28_09.57.33_310: verbose [int main():162] = Took: 0.017689
2014.08.28_09.57.33_328: verbose [int main():162] = Took: 0.017360
2014.08.28_09.57.33_359: verbose [int main():162] = Took: 0.029582
2014.08.28_09.57.33_377: verbose [int main():162] = Took: 0.014137
2014.08.28_09.57.33_411: verbose [int main():162] = Took: 0.030622
2014.08.28_09.57.33_424: verbose [int main():162] = Took: 0.009725
2014.08.28_09.57.33_461: verbose [int main():162] = Took: 0.016294
2014.08.28_09.57.33_474: verbose [int main():162] = Took: 0.012158
2014.08.28_09.57.33_495: verbose [int main():162] = Took: 0.019164
2014.08.28_09.57.33_511: verbose [int main():162] = Took: 0.009864
2014.08.28_09.57.33_528: verbose [int main():162] = Took: 0.015752
2014.08.28_09.57.33_541: verbose [int main():162] = Took: 0.011591
2014.08.28_09.57.33_560: verbose [int main():162] = Took: 0.017273
2014.08.28_09.57.33_578: verbose [int main():162] = Took: 0.016341
2014.08.28_09.57.33_592: verbose [int main():162] = Took: 0.012830
2014.08.28_09.57.33_616: verbose [int main():162] = Took: 0.016965
2014.08.28_09.57.34_640: verbose [int main():162] = Took: 0.021996
2014.08.28_09.57.34_662: verbose [int main():162] = Took: 0.004950
2014.08.28_09.57.34_678: verbose [int main():162] = Took: 0.013562
2014.08.28_09.57.34_700: verbose [int main():162] = Took: 0.020186
2014.08.28_09.57.34_716: verbose [int main():162] = Took: 0.009004
2014.08.28_09.57.34_741: verbose [int main():162] = Took: 0.023935
2014.08.28_09.57.34_778: verbose [int main():162] = Took: 0.030341
2014.08.28_09.57.34_796: verbose [int main():162] = Took: 0.016939
2014.08.28_09.57.34_828: verbose [int main():162] = Took: 0.021799
2014.08.28_09.57.34_842: verbose [int main():162] = Took: 0.009358
2014.08.28_09.57.34_878: verbose [int main():162] = Took: 0.019993
2014.08.28_09.57.34_896: verbose [int main():162] = Took: 0.016433
2014.08.28_09.57.34_926: verbose [int main():162] = Took: 0.028643
2014.08.28_09.57.34_945: verbose [int main():162] = Took: 0.014017
2014.08.28_09.57.34_978: verbose [int main():162] = Took: 0.031791
2014.08.28_09.57.34_997: verbose [int main():162] = Took: 0.016920
2014.08.28_09.57.34_16: verbose [int main():162] = Took: 0.018063
2014.08.28_09.57.34_43: verbose [int main():162] = Took: 0.008069
2014.08.28_09.57.34_62: verbose [int main():162] = Took: 0.016659
2014.08.28_09.57.34_95: verbose [int main():162] = Took: 0.031220
2014.08.28_09.57.34_112: verbose [int main():162] = Took: 0.016076
2014.08.28_09.57.34_145: verbose [int main():162] = Took: 0.025039
2014.08.28_09.57.34_163: verbose [int main():162] = Took: 0.016290
2014.08.28_09.57.34_195: verbose [int main():162] = Took: 0.028162
2014.08.28_09.57.34_213: verbose [int main():162] = Took: 0.016082
2014.08.28_09.57.34_245: verbose [int main():162] = Took: 0.031331
2014.08.28_09.57.34_264: verbose [int main():162] = Took: 0.016281
2014.08.28_09.57.34_296: verbose [int main():162] = Took: 0.020673
2014.08.28_09.57.34_313: verbose [int main():162] = Took: 0.015207
2014.08.28_09.57.34_346: verbose [int main():162] = Took: 0.031821
2014.08.28_09.57.34_368: verbose [int main():162] = Took: 0.020428
2014.08.28_09.57.34_397: verbose [int main():162] = Took: 0.022230
2014.08.28_09.57.34_413: verbose [int main():162] = Took: 0.014551
2014.08.28_09.57.34_446: verbose [int main():162] = Took: 0.032402
2014.08.28_09.57.34_466: verbose [int main():162] = Took: 0.017916
2014.08.28_09.57.34_496: verbose [int main():162] = Took: 0.028936
2014.08.28_09.57.34_514: verbose [int main():162] = Took: 0.013146
2014.08.28_09.57.34_546: verbose [int main():162] = Took: 0.022253
2014.08.28_09.57.34_563: verbose [int main():162] = Took: 0.013557
2014.08.28_09.57.34_594: verbose [int main():162] = Took: 0.029427
2014.08.28_09.57.34_610: verbose [int main():162] = Took: 0.013754
2014.08.28_09.57.35_647: verbose [int main():162] = Took: 0.019401
2014.08.28_09.57.35_667: verbose [int main():162] = Took: 0.018647
2014.08.28_09.57.35_695: verbose [int main():162] = Took: 0.024147
2014.08.28_09.57.35_711: verbose [int main():162] = Took: 0.013650
2014.08.28_09.57.35_747: verbose [int main():162] = Took: 0.019825
2014.08.28_09.57.35_761: verbose [int main():162] = Took: 0.010776
2014.08.28_09.57.35_779: verbose [int main():162] = Took: 0.015481
2014.08.28_09.57.35_797: verbose [int main():162] = Took: 0.016900
@scheibel

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commented Apr 26, 2019

Can you add the main function you're using? I think you get such differing upload times because you don't wait for the completion of the uploads for your time measurements.

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