/** Update shadowSplit values and make Cascade Bounding Box pointer valid.
* The function aunches two compute kernel that generates an histogram of the depth buffer value (between 0 and 250 with increment of 0.25)
* and get an axis aligned bounding box (from SunCamMatrix view) containing all depth buffer value.
* It also retrieves the result from the previous computations (in a Round Robin fashion) and update CBB pointer.
* \param width of the depth buffer
* \param height of the depth buffer
* TODO : The depth histogram part is commented out, needs to tweak it when I have some motivation
*/
void IrrDriver::UpdateSplitAndLightcoordRangeFromComputeShaders(size_t width, size_t height)
{
// Value that should be kept between multiple calls
static bool ssboInit = false;
static GLuint CBBssbo, tempShadowMatssbo;
CascadeBoundingBox InitialCBB[4];
for (unsigned i = 0; i < 4; i++)
{
InitialCBB[i].xmin = InitialCBB[i].ymin = InitialCBB[i].zmin = 1000;
InitialCBB[i].xmax = InitialCBB[i].ymax = InitialCBB[i].zmax = -1000;
}
if (!ssboInit)
{
glGenBuffers(1, &CBBssbo);
glGenBuffers(1, &tempShadowMatssbo);
ssboInit = true;
}
glBindBuffer(GL_SHADER_STORAGE_BUFFER, CBBssbo);
glBufferData(GL_SHADER_STORAGE_BUFFER, 4 * sizeof(CascadeBoundingBox), InitialCBB, GL_STATIC_DRAW);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, CBBssbo);
glUseProgram(FullScreenShader::LightspaceBoundingBoxShader::getInstance()->Program);
FullScreenShader::LightspaceBoundingBoxShader::getInstance()->SetTextureUnits(getDepthStencilTexture());
FullScreenShader::LightspaceBoundingBoxShader::getInstance()->setUniforms(m_suncam->getViewMatrix(), shadowSplit[1], shadowSplit[2], shadowSplit[3], shadowSplit[4]);
glDispatchCompute((int)width / 64, (int)height / 64, 1);
glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, tempShadowMatssbo);
glBufferData(GL_SHADER_STORAGE_BUFFER, 4 * 16 * sizeof(float), 0, GL_STATIC_COPY);
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, tempShadowMatssbo);
glUseProgram(FullScreenShader::ShadowMatrixesGenerationShader::getInstance()->Program);
FullScreenShader::ShadowMatrixesGenerationShader::getInstance()->setUniforms(m_suncam->getViewMatrix());
glDispatchCompute(4, 1, 1);
glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT);
glBindBuffer(GL_COPY_READ_BUFFER, tempShadowMatssbo);
glBindBuffer(GL_COPY_WRITE_BUFFER, SharedObject::ViewProjectionMatrixesUBO);
glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, 0, 80 * sizeof(float), 4 * 16 * sizeof(float));
}
/** Update shadowSplit values and make Cascade Bounding Box pointer valid.
* The function aunches two compute kernel that generates an histogram of the depth buffer value (between 0 and 250 with increment of 0.25)
* and get an axis aligned bounding box (from SunCamMatrix view) containing all depth buffer value.
* It also retrieves the result from the previous computations (in a Round Robin fashion) and update CBB pointer.
* \param width of the depth buffer
* \param height of the depth buffer
* TODO : The depth histogram part is commented out, needs to tweak it when I have some motivation
*/
void IrrDriver::UpdateSplitAndLightcoordRangeFromComputeShaders(size_t width, size_t height)
{
// Value that should be kept between multiple calls
static GLuint ssbo[2];
static Histogram *Hist[2];
static GLsync LightcoordBBFence = 0;
static size_t currentHist = 0;
static GLuint ssboSplit[2];
static float tmpshadowSplit[5] = { 1., 5., 20., 50., 150. };
if (!LightcoordBBFence)
{
glGenBuffers(2, ssbo);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo[0]);
glBufferStorage(GL_SHADER_STORAGE_BUFFER, 4 * sizeof(CascadeBoundingBox), 0, GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
CBB[0] = (CascadeBoundingBox *)glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0, 4 * sizeof(CascadeBoundingBox), GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo[1]);
glBufferStorage(GL_SHADER_STORAGE_BUFFER, 4 * sizeof(CascadeBoundingBox), 0, GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
CBB[1] = (CascadeBoundingBox *)glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0, 4 * sizeof(CascadeBoundingBox), GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
/* glGenBuffers(2, ssboSplit);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssboSplit[0]);
glBufferStorage(GL_SHADER_STORAGE_BUFFER, sizeof(Histogram), 0, GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
Hist[0] = (Histogram *)glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0, sizeof(Histogram), GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssboSplit[1]);
glBufferStorage(GL_SHADER_STORAGE_BUFFER, sizeof(Histogram), 0, GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
Hist[1] = (Histogram *)glMapBufferRange(GL_SHADER_STORAGE_BUFFER, 0, sizeof(Histogram), GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT | GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);*/
}
// Use bounding boxes from last frame
if (LightcoordBBFence)
{
while (glClientWaitSync(LightcoordBBFence, GL_SYNC_FLUSH_COMMANDS_BIT, 0) != GL_ALREADY_SIGNALED);
glDeleteSync(LightcoordBBFence);
}
/* {
memcpy(shadowSplit, tmpshadowSplit, 5 * sizeof(float));
unsigned numpix = Hist[currentHist]->count;
unsigned split = 0;
unsigned i;
for (i = 0; i < 1022; i++)
{
split += Hist[currentHist]->bin[i];
if (split > numpix / 2)
break;
}
tmpshadowSplit[1] = (float)++i / 4.;
for (; i < 1023; i++)
{
split += Hist[currentHist]->bin[i];
if (split > 3 * numpix / 4)
break;
}
tmpshadowSplit[2] = (float)++i / 4.;
for (; i < 1024; i++)
{
split += Hist[currentHist]->bin[i];
if (split > 7 * numpix / 8)
break;
}
tmpshadowSplit[3] = (float)++i / 4.;
for (; i < 1024; i++)
{
split += Hist[currentHist]->bin[i];
}
tmpshadowSplit[0] = (float)(Hist[currentHist]->bin[1024] - 1) / 4.;
tmpshadowSplit[4] = (float)(Hist[currentHist]->bin[1025] + 1) / 4.;
printf("numpix is %d\n", numpix);
printf("total : %d\n", split);
printf("split 0 : %f\n", tmpshadowSplit[1]);
printf("split 1 : %f\n", tmpshadowSplit[2]);
printf("split 2 : %f\n", tmpshadowSplit[3]);
printf("min %f max %f\n", tmpshadowSplit[0], tmpshadowSplit[4]);
currentHist = (currentHist + 1) % 2;
}*/
glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 2, ssbo[currentCBB]);
// glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 1, ssboSplit[currentHist]);
for (unsigned i = 0; i < 4; i++)
{
CBB[currentCBB][i].xmin = CBB[currentCBB][i].ymin = CBB[currentCBB][i].zmin = 1000;
CBB[currentCBB][i].xmax = CBB[currentCBB][i].ymax = CBB[currentCBB][i].zmax = -1000;
}
// memset(Hist[currentHist], 0, sizeof(Histogram));
// Hist[currentHist]->mindepth = 3000;
glMemoryBarrier(GL_BUFFER_UPDATE_BARRIER_BIT);
glUseProgram(FullScreenShader::LightspaceBoundingBoxShader::getInstance()->Program);
FullScreenShader::LightspaceBoundingBoxShader::getInstance()->SetTextureUnits(getDepthStencilTexture());
FullScreenShader::LightspaceBoundingBoxShader::getInstance()->setUniforms(m_suncam->getViewMatrix(), tmpshadowSplit[1], tmpshadowSplit[2], tmpshadowSplit[3], tmpshadowSplit[4]);
glDispatchCompute((int)width / 64, (int)height / 64, 1);
/* glUseProgram(FullScreenShader::DepthHistogramShader::getInstance()->Program);
FullScreenShader::DepthHistogramShader::getInstance()->SetTextureUnits(getDepthStencilTexture());
FullScreenShader::DepthHistogramShader::getInstance()->setUniforms();
glDispatchCompute((int)width / 32, (int)height / 32, 1);*/
glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT);
LightcoordBBFence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
currentCBB = (currentCBB + 1) % 2;
}