int makeUniformBlockSlots(GLuint glprogram, const Shader::BindingSet& slotBindings, Shader::SlotSet& buffers) {
GLint buffersCount = 0;
glGetProgramiv(glprogram, GL_ACTIVE_UNIFORM_BLOCKS, &buffersCount);
// fast exit
if (buffersCount == 0) {
return 0;
}
GLint maxNumUniformBufferSlots = 0;
glGetIntegerv(GL_MAX_UNIFORM_BUFFER_BINDINGS, &maxNumUniformBufferSlots);
std::vector<GLint> uniformBufferSlotMap(maxNumUniformBufferSlots, -1);
for (int i = 0; i < buffersCount; i++) {
const GLint NAME_LENGTH = 256;
GLchar name[NAME_LENGTH];
GLint length = 0;
GLint size = 0;
GLint binding = -1;
glGetActiveUniformBlockiv(glprogram, i, GL_UNIFORM_BLOCK_NAME_LENGTH, &length);
glGetActiveUniformBlockName(glprogram, i, NAME_LENGTH, &length, name);
glGetActiveUniformBlockiv(glprogram, i, GL_UNIFORM_BLOCK_BINDING, &binding);
glGetActiveUniformBlockiv(glprogram, i, GL_UNIFORM_BLOCK_DATA_SIZE, &size);
GLuint blockIndex = glGetUniformBlockIndex(glprogram, name);
// CHeck if there is a requested binding for this block
auto requestedBinding = slotBindings.find(std::string(name));
if (requestedBinding != slotBindings.end()) {
// If yes force it
if (binding != (*requestedBinding)._location) {
binding = (*requestedBinding)._location;
glUniformBlockBinding(glprogram, blockIndex, binding);
}
} else if (binding == 0) {
// If no binding was assigned then just do it finding a free slot
auto slotIt = std::find_if(uniformBufferSlotMap.begin(), uniformBufferSlotMap.end(), isUnusedSlot);
if (slotIt != uniformBufferSlotMap.end()) {
binding = slotIt - uniformBufferSlotMap.begin();
glUniformBlockBinding(glprogram, blockIndex, binding);
} else {
// This should neve happen, an active ubo cannot find an available slot among the max available?!
binding = -1;
}
}
// If binding is valid record it
if (binding >= 0) {
uniformBufferSlotMap[binding] = blockIndex;
}
Element element(SCALAR, gpu::UINT32, gpu::UNIFORM_BUFFER);
buffers.insert(Shader::Slot(name, binding, element, Resource::BUFFER));
}
return buffersCount;
}
int GL45Backend::makeResourceBufferSlots(GLuint glprogram, const Shader::BindingSet& slotBindings,Shader::SlotSet& resourceBuffers) {
GLint buffersCount = 0;
glGetProgramInterfaceiv(glprogram, GL_SHADER_STORAGE_BLOCK, GL_ACTIVE_RESOURCES, &buffersCount);
// fast exit
if (buffersCount == 0) {
return 0;
}
GLint maxNumResourceBufferSlots = 0;
glGetIntegerv(GL_MAX_SHADER_STORAGE_BUFFER_BINDINGS, &maxNumResourceBufferSlots);
std::vector<GLint> resourceBufferSlotMap(maxNumResourceBufferSlots, -1);
struct ResourceBlockInfo {
using Vector = std::vector<ResourceBlockInfo>;
const GLuint index{ 0 };
const std::string name;
GLint binding{ -1 };
GLint size{ 0 };
static std::string getName(GLuint glprogram, GLuint i) {
static const GLint NAME_LENGTH = 256;
GLint length = 0;
GLchar nameBuffer[NAME_LENGTH];
glGetProgramResourceName(glprogram, GL_SHADER_STORAGE_BLOCK, i, NAME_LENGTH, &length, nameBuffer);
return std::string(nameBuffer);
}
ResourceBlockInfo(GLuint glprogram, GLuint i) : index(i), name(getName(glprogram, i)) {
GLenum props[2] = { GL_BUFFER_BINDING, GL_BUFFER_DATA_SIZE};
glGetProgramResourceiv(glprogram, GL_SHADER_STORAGE_BLOCK, i, 2, props, 2, nullptr, &binding);
}
};
ResourceBlockInfo::Vector resourceBlocks;
resourceBlocks.reserve(buffersCount);
for (int i = 0; i < buffersCount; i++) {
resourceBlocks.push_back(ResourceBlockInfo(glprogram, i));
}
for (auto& info : resourceBlocks) {
auto requestedBinding = slotBindings.find(info.name);
if (requestedBinding != slotBindings.end()) {
info.binding = (*requestedBinding)._location;
glUniformBlockBinding(glprogram, info.index, info.binding);
resourceBufferSlotMap[info.binding] = info.index;
}
}
for (auto& info : resourceBlocks) {
if (slotBindings.count(info.name)) {
continue;
}
// If the binding is -1, or the binding maps to an already used binding
if (info.binding == -1 || !isUnusedSlot(resourceBufferSlotMap[info.binding])) {
// If no binding was assigned then just do it finding a free slot
auto slotIt = std::find_if(resourceBufferSlotMap.begin(), resourceBufferSlotMap.end(), GLBackend::isUnusedSlot);
if (slotIt != resourceBufferSlotMap.end()) {
info.binding = slotIt - resourceBufferSlotMap.begin();
glUniformBlockBinding(glprogram, info.index, info.binding);
} else {
// This should never happen, an active ssbo cannot find an available slot among the max available?!
info.binding = -1;
}
}
resourceBufferSlotMap[info.binding] = info.index;
}
for (auto& info : resourceBlocks) {
static const Element element(SCALAR, gpu::UINT32, gpu::RESOURCE_BUFFER);
resourceBuffers.insert(Shader::Slot(info.name, info.binding, element, Resource::BUFFER, info.size));
}
return buffersCount;
/*
GLint ssboCount = 0;
glGetProgramInterfaceiv(glprogram, GL_SHADER_STORAGE_BLOCK, GL_ACTIVE_RESOURCES, &ssboCount);
if (ssboCount > 0) {
GLint maxNameLength = 0;
glGetProgramInterfaceiv(glprogram, GL_SHADER_STORAGE_BLOCK, GL_MAX_NAME_LENGTH, &maxNameLength);
std::vector<GLchar> nameBytes(maxNameLength);
for (GLint b = 0; b < ssboCount; b++) {
GLint length;
glGetProgramResourceName(glprogram, GL_SHADER_STORAGE_BLOCK, b, maxNameLength, &length, nameBytes.data());
std::string bufferName(nameBytes.data());
GLenum props = GL_BUFFER_BINDING;
GLint binding = -1;
glGetProgramResourceiv(glprogram, GL_SHADER_STORAGE_BLOCK, b, 1, &props, 1, nullptr, &binding);
auto requestedBinding = slotBindings.find(std::string(bufferName));
if (requestedBinding != slotBindings.end()) {
if (binding != (*requestedBinding)._location) {
binding = (*requestedBinding)._location;
glShaderStorageBlockBinding(glprogram, b, binding);
}
}
static const Element element(SCALAR, gpu::UINT32, gpu::RESOURCE_BUFFER);
resourceBuffers.insert(Shader::Slot(bufferName, binding, element, -1));
}
}
return ssboCount;*/
}
int makeUniformSlots(GLuint glprogram, const Shader::BindingSet& slotBindings, Shader::SlotSet& uniforms, Shader::SlotSet& textures, Shader::SlotSet& samplers) {
GLint uniformsCount = 0;
#if (GPU_FEATURE_PROFILE == GPU_LEGACY)
GLint currentProgram = 0;
glGetIntegerv(GL_CURRENT_PROGRAM, ¤tProgram);
glUseProgram(glprogram);
#endif
glGetProgramiv(glprogram, GL_ACTIVE_UNIFORMS, &uniformsCount);
for (int i = 0; i < uniformsCount; i++) {
const GLint NAME_LENGTH = 256;
GLchar name[NAME_LENGTH];
GLint length = 0;
GLint size = 0;
GLenum type = 0;
glGetActiveUniform(glprogram, i, NAME_LENGTH, &length, &size, &type, name);
GLint location = glGetUniformLocation(glprogram, name);
const GLint INVALID_UNIFORM_LOCATION = -1;
// Try to make sense of the gltype
auto elementResource = getFormatFromGLUniform(type);
// The uniform as a standard var type
if (location != INVALID_UNIFORM_LOCATION) {
// Let's make sure the name doesn't contains an array element
std::string sname(name);
auto foundBracket = sname.find_first_of('[');
if (foundBracket != std::string::npos) {
// std::string arrayname = sname.substr(0, foundBracket);
if (sname[foundBracket + 1] == '0') {
sname = sname.substr(0, foundBracket);
} else {
// skip this uniform since it's not the first element of an array
continue;
}
}
if (elementResource._resource == Resource::BUFFER) {
uniforms.insert(Shader::Slot(sname, location, elementResource._element, elementResource._resource));
} else {
// For texture/Sampler, the location is the actual binding value
GLint binding = -1;
glGetUniformiv(glprogram, location, &binding);
auto requestedBinding = slotBindings.find(std::string(sname));
if (requestedBinding != slotBindings.end()) {
if (binding != (*requestedBinding)._location) {
binding = (*requestedBinding)._location;
#if (GPU_FEATURE_PROFILE == GPU_LEGACY)
glUniform1i(location, binding);
#else
glProgramUniform1i(glprogram, location, binding);
#endif
}
}
textures.insert(Shader::Slot(name, binding, elementResource._element, elementResource._resource));
samplers.insert(Shader::Slot(name, binding, elementResource._element, elementResource._resource));
}
}
}
#if (GPU_FEATURE_PROFILE == GPU_LEGACY)
glUseProgram(currentProgram);
#endif
return uniformsCount;
}