Use UBOs instead of glUniform. Work in progress; no clear wins seen yet. ubo
authorSteinar H. Gunderson <steinar+vlc@gunderson.no>
Tue, 23 Feb 2016 21:33:18 +0000 (22:33 +0100)
committerSteinar H. Gunderson <steinar+vlc@gunderson.no>
Tue, 23 Feb 2016 21:33:18 +0000 (22:33 +0100)
effect.h
effect_chain.cpp
effect_chain.h
effect_util.cpp
effect_util.h
header.130.frag

index 67e6423..d812db0 100644 (file)
--- a/effect.h
+++ b/effect.h
@@ -59,7 +59,9 @@ struct Uniform {
        const T *value;  // Owner by the effect.
        size_t num_values;  // Number of elements; for arrays only. _Not_ the vector length.
        std::string prefix;  // Filled in only after phases have been constructed.
-       GLint location;  // Filled in only after phases have been constructed. -1 if no location.
+       GLuint location;  // Filled in only after phases have been constructed. GL_INVALID_INDEX if no location, or if using UBOs.
+       GLint ubo_offset;  // Same. -1 if no location or if not using UBOs.
+       GLint ubo_num_elem; // Same. 0 if no location or if not using UBOs.
 };
 
 class Effect {
index fa7340d..f800d1e 100644 (file)
@@ -275,6 +275,7 @@ template<class T>
 void extract_uniform_declarations(const vector<Uniform<T> > &effect_uniforms,
                                   const string &type_specifier,
                                   const string &effect_id,
+                                  bool in_ubo_block,
                                   vector<Uniform<T> > *phase_uniforms,
                                   string *glsl_string)
 {
@@ -282,8 +283,10 @@ void extract_uniform_declarations(const vector<Uniform<T> > &effect_uniforms,
                phase_uniforms->push_back(effect_uniforms[i]);
                phase_uniforms->back().prefix = effect_id;
 
-               *glsl_string += string("uniform ") + type_specifier + " " + effect_id
-                       + "_" + effect_uniforms[i].name + ";\n";
+               if (!in_ubo_block) {
+                       *glsl_string += "uniform ";
+               }
+               *glsl_string += type_specifier + " " + effect_id + "_" + effect_uniforms[i].name + ";\n";
        }
 }
 
@@ -291,6 +294,7 @@ template<class T>
 void extract_uniform_array_declarations(const vector<Uniform<T> > &effect_uniforms,
                                         const string &type_specifier,
                                         const string &effect_id,
+                                        bool in_ubo_block,
                                         vector<Uniform<T> > *phase_uniforms,
                                         string *glsl_string)
 {
@@ -298,8 +302,12 @@ void extract_uniform_array_declarations(const vector<Uniform<T> > &effect_unifor
                phase_uniforms->push_back(effect_uniforms[i]);
                phase_uniforms->back().prefix = effect_id;
 
+               if (!in_ubo_block) {
+                       *glsl_string += "uniform ";
+               }
+
                char buf[256];
-               snprintf(buf, sizeof(buf), "uniform %s %s_%s[%d];\n",
+               snprintf(buf, sizeof(buf), "%s %s_%s[%d];\n",
                        type_specifier.c_str(), effect_id.c_str(),
                        effect_uniforms[i].name.c_str(),
                        int(effect_uniforms[i].num_values));
@@ -313,6 +321,7 @@ void collect_uniform_locations(GLuint glsl_program_num, vector<Uniform<T> > *pha
        for (unsigned i = 0; i < phase_uniforms->size(); ++i) {
                Uniform<T> &uniform = (*phase_uniforms)[i];
                uniform.location = get_uniform_location(glsl_program_num, uniform.prefix, uniform.name);
+               get_uniform_offset_and_size(glsl_program_num, uniform.prefix, uniform.name, &uniform.ubo_offset, &uniform.ubo_num_elem);
        }
 }
 
@@ -422,24 +431,34 @@ void EffectChain::compile_glsl_program(Phase *phase)
        // before in the output source, since output_fragment_shader() is allowed
        // to register new uniforms (e.g. arrays that are of unknown length until
        // finalization time).
-       // TODO: Make a uniform block for platforms that support it.
        string frag_shader_uniforms = "";
        for (unsigned i = 0; i < phase->effects.size(); ++i) {
+               const bool in_ubo_block = true;  // TODO: Check for the extension.
                Node *node = phase->effects[i];
                Effect *effect = node->effect;
                const string effect_id = phase->effect_ids[node];
-               extract_uniform_declarations(effect->uniforms_sampler2d, "sampler2D", effect_id, &phase->uniforms_sampler2d, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_bool, "bool", effect_id, &phase->uniforms_bool, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_int, "int", effect_id, &phase->uniforms_int, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_float, "float", effect_id, &phase->uniforms_float, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_vec2, "vec2", effect_id, &phase->uniforms_vec2, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_vec3, "vec3", effect_id, &phase->uniforms_vec3, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_vec4, "vec4", effect_id, &phase->uniforms_vec4, &frag_shader_uniforms);
-               extract_uniform_array_declarations(effect->uniforms_float_array, "float", effect_id, &phase->uniforms_float, &frag_shader_uniforms);
-               extract_uniform_array_declarations(effect->uniforms_vec2_array, "vec2", effect_id, &phase->uniforms_vec2, &frag_shader_uniforms);
-               extract_uniform_array_declarations(effect->uniforms_vec3_array, "vec3", effect_id, &phase->uniforms_vec3, &frag_shader_uniforms);
-               extract_uniform_array_declarations(effect->uniforms_vec4_array, "vec4", effect_id, &phase->uniforms_vec4, &frag_shader_uniforms);
-               extract_uniform_declarations(effect->uniforms_mat3, "mat3", effect_id, &phase->uniforms_mat3, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_bool, "bool", effect_id, in_ubo_block, &phase->uniforms_bool, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_int, "int", effect_id, in_ubo_block, &phase->uniforms_int, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_float, "float", effect_id, in_ubo_block, &phase->uniforms_float, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_vec2, "vec2", effect_id, in_ubo_block, &phase->uniforms_vec2, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_vec3, "vec3", effect_id, in_ubo_block, &phase->uniforms_vec3, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_vec4, "vec4", effect_id, in_ubo_block, &phase->uniforms_vec4, &frag_shader_uniforms);
+               extract_uniform_array_declarations(effect->uniforms_float_array, "float", effect_id, in_ubo_block, &phase->uniforms_float, &frag_shader_uniforms);
+               extract_uniform_array_declarations(effect->uniforms_vec2_array, "vec2", effect_id, in_ubo_block, &phase->uniforms_vec2, &frag_shader_uniforms);
+               extract_uniform_array_declarations(effect->uniforms_vec3_array, "vec3", effect_id, in_ubo_block, &phase->uniforms_vec3, &frag_shader_uniforms);
+               extract_uniform_array_declarations(effect->uniforms_vec4_array, "vec4", effect_id, in_ubo_block, &phase->uniforms_vec4, &frag_shader_uniforms);
+               extract_uniform_declarations(effect->uniforms_mat3, "mat3", effect_id, in_ubo_block, &phase->uniforms_mat3, &frag_shader_uniforms);
+       }
+       if (!frag_shader_uniforms.empty()) {
+               frag_shader_uniforms = "layout(packed) uniform MovitUniforms {\n" + frag_shader_uniforms + "};\n";
+       }
+
+       // Samplers must be outside the UBO block.
+       for (unsigned i = 0; i < phase->effects.size(); ++i) {
+               Node *node = phase->effects[i];
+               Effect *effect = node->effect;
+               const string effect_id = phase->effect_ids[node];
+               extract_uniform_declarations(effect->uniforms_sampler2d, "sampler2D", effect_id, /*in_ubo_block=*/false, &phase->uniforms_sampler2d, &frag_shader_uniforms);
        }
 
        frag_shader = frag_shader_header + frag_shader_uniforms + frag_shader;
@@ -466,6 +485,34 @@ void EffectChain::compile_glsl_program(Phase *phase)
                phase->attribute_indexes.insert(texcoord_attribute_index);
        }
 
+       // Create an UBO for holding the uniforms. This UBO will be updated each frame.
+       // TODO: Delete the block on destruction.
+       phase->uniform_block_index = glGetUniformBlockIndex(phase->glsl_program_num, "MovitUniforms");
+       if (phase->uniform_block_index != GL_INVALID_INDEX) {
+               glGenBuffers(1, &phase->ubo);
+               check_error();
+               GLsizei block_size;
+               glGetActiveUniformBlockiv(
+                       phase->glsl_program_num, phase->uniform_block_index,
+                       GL_UNIFORM_BLOCK_DATA_SIZE, &block_size);
+               check_error();
+               phase->ubo_data.resize(block_size);
+
+               glBindBuffer(GL_UNIFORM_BUFFER, phase->ubo);
+               check_error();
+               glBufferData(GL_UNIFORM_BUFFER, block_size, NULL, GL_DYNAMIC_DRAW);
+               check_error();
+
+               // Associate the uniform block with binding point 0,
+               // and attach the UBO to that binding point.
+               glUniformBlockBinding(phase->glsl_program_num, phase->uniform_block_index, 0);
+               check_error();
+               glBindBufferBase(GL_UNIFORM_BUFFER, 0, phase->ubo);
+               check_error();
+       } else {
+               phase->ubo = GL_INVALID_INDEX;
+       }
+
        // Collect the resulting location numbers for each uniform.
        collect_uniform_locations(phase->glsl_program_num, &phase->uniforms_sampler2d);
        collect_uniform_locations(phase->glsl_program_num, &phase->uniforms_bool);
@@ -475,6 +522,9 @@ void EffectChain::compile_glsl_program(Phase *phase)
        collect_uniform_locations(phase->glsl_program_num, &phase->uniforms_vec3);
        collect_uniform_locations(phase->glsl_program_num, &phase->uniforms_vec4);
        collect_uniform_locations(phase->glsl_program_num, &phase->uniforms_mat3);
+
+       glBindBuffer(GL_UNIFORM_BUFFER, 0);
+       check_error();
 }
 
 // Construct GLSL programs, starting at the given effect and following
@@ -1946,54 +1996,75 @@ void EffectChain::execute_phase(Phase *phase, bool last_phase,
 
 void EffectChain::setup_uniforms(Phase *phase)
 {
-       // TODO: Use UBO blocks.
+       char *ubo_data = phase->ubo_data.empty() ? NULL : &phase->ubo_data[0];
+
        for (size_t i = 0; i < phase->uniforms_sampler2d.size(); ++i) {
                const Uniform<int> &uniform = phase->uniforms_sampler2d[i];
-               if (uniform.location != -1) {
+               if (uniform.location != GL_INVALID_INDEX) {
                        glUniform1iv(uniform.location, uniform.num_values, uniform.value);
                }
+               assert(uniform.ubo_offset == -1);  // Samplers don't go into UBOs.
        }
        for (size_t i = 0; i < phase->uniforms_bool.size(); ++i) {
                const Uniform<bool> &uniform = phase->uniforms_bool[i];
                assert(uniform.num_values == 1);
-               if (uniform.location != -1) {
+               if (uniform.location != GL_INVALID_INDEX) {
                        glUniform1i(uniform.location, *uniform.value);
                }
+               if (uniform.ubo_offset != -1) {
+                       GLint int_val = *uniform.value;
+                       memcpy(ubo_data + uniform.ubo_offset, &int_val, sizeof(int_val));
+               }
        }
        for (size_t i = 0; i < phase->uniforms_int.size(); ++i) {
                const Uniform<int> &uniform = phase->uniforms_int[i];
-               if (uniform.location != -1) {
+               if (uniform.location != GL_INVALID_INDEX) {
                        glUniform1iv(uniform.location, uniform.num_values, uniform.value);
                }
+               if (uniform.ubo_offset != -1) {
+                       memcpy(ubo_data + uniform.ubo_offset, uniform.value, uniform.ubo_num_elem * sizeof(*uniform.value));
+               }
        }
        for (size_t i = 0; i < phase->uniforms_float.size(); ++i) {
                const Uniform<float> &uniform = phase->uniforms_float[i];
-               if (uniform.location != -1) {
+               if (uniform.location != GL_INVALID_INDEX) {
                        glUniform1fv(uniform.location, uniform.num_values, uniform.value);
                }
+               if (uniform.ubo_offset != -1) {
+                       memcpy(ubo_data + uniform.ubo_offset, uniform.value, uniform.ubo_num_elem * sizeof(*uniform.value));
+               }
        }
        for (size_t i = 0; i < phase->uniforms_vec2.size(); ++i) {
                const Uniform<float> &uniform = phase->uniforms_vec2[i];
-               if (uniform.location != -1) {
-                       glUniform2fv(uniform.location, uniform.num_values, uniform.value);
+               if (uniform.location != GL_INVALID_INDEX) {
+                       glUniform2fv(uniform.location, uniform.ubo_num_elem, uniform.value);
+               }
+               if (uniform.ubo_offset != -1) {
+                       memcpy(ubo_data + uniform.ubo_offset, uniform.value, uniform.ubo_num_elem * 2 * sizeof(*uniform.value));
                }
        }
        for (size_t i = 0; i < phase->uniforms_vec3.size(); ++i) {
                const Uniform<float> &uniform = phase->uniforms_vec3[i];
-               if (uniform.location != -1) {
-                       glUniform3fv(uniform.location, uniform.num_values, uniform.value);
+               if (uniform.location != GL_INVALID_INDEX) {
+                       glUniform3fv(uniform.location, uniform.ubo_num_elem, uniform.value);
+               }
+               if (uniform.ubo_offset != -1) {
+                       memcpy(ubo_data + uniform.ubo_offset, uniform.value, uniform.ubo_num_elem * 3 * sizeof(*uniform.value));
                }
        }
        for (size_t i = 0; i < phase->uniforms_vec4.size(); ++i) {
                const Uniform<float> &uniform = phase->uniforms_vec4[i];
-               if (uniform.location != -1) {
-                       glUniform4fv(uniform.location, uniform.num_values, uniform.value);
+               if (uniform.location != GL_INVALID_INDEX) {
+                       glUniform4fv(uniform.location, uniform.ubo_num_elem, uniform.value);
+               }
+               if (uniform.ubo_offset != -1) {
+                       memcpy(ubo_data + uniform.ubo_offset, uniform.value, uniform.ubo_num_elem * 4 * sizeof(*uniform.value));
                }
        }
        for (size_t i = 0; i < phase->uniforms_mat3.size(); ++i) {
                const Uniform<Matrix3d> &uniform = phase->uniforms_mat3[i];
-               assert(uniform.num_values == 1);
-               if (uniform.location != -1) {
+               assert(uniform.ubo_num_elem == 1);
+               if (uniform.location != GL_INVALID_INDEX) {
                        // Convert to float (GLSL has no double matrices).
                        float matrixf[9];
                        for (unsigned y = 0; y < 3; ++y) {
@@ -2003,6 +2074,16 @@ void EffectChain::setup_uniforms(Phase *phase)
                        }
                        glUniformMatrix3fv(uniform.location, 1, GL_FALSE, matrixf);
                }
+               if (uniform.ubo_offset != -1) {
+                       // TODO
+                       assert(false);
+               }
+       }
+
+       if (phase->ubo != GL_INVALID_INDEX) {
+               // TODO: Do we want to demand DSA for this?
+               glNamedBufferSubData(phase->ubo, 0, phase->ubo_data.size(), ubo_data);
+               return;
        }
 }
 
index 718d5ff..de50512 100644 (file)
@@ -179,6 +179,10 @@ struct Phase {
        std::vector<Uniform<float> > uniforms_vec4;
        std::vector<Uniform<Eigen::Matrix3d> > uniforms_mat3;
 
+       GLuint ubo;  // GL_INVALID_INDEX if not using UBOs.
+       GLuint uniform_block_index;
+       std::vector<char> ubo_data;
+
        // For measurement of GPU time used.
        std::list<GLuint> timer_query_objects_running;
        std::list<GLuint> timer_query_objects_free;
index dbeb48b..4036caf 100644 (file)
@@ -14,6 +14,24 @@ GLint get_uniform_location(GLuint glsl_program_num, const string &prefix, const
        return glGetUniformLocation(glsl_program_num, name.c_str());
 }
 
+void get_uniform_offset_and_size(GLuint glsl_program_num, const string &prefix, const string &key, GLint *offset, GLint *size)
+{
+       string name = prefix + "_" + key;
+       GLuint index;
+       const GLchar *name_cstr = name.c_str();
+       glGetUniformIndices(glsl_program_num, 1, &name_cstr, &index);
+       check_error();
+       if (index == GL_INVALID_INDEX) {
+               *offset = -1;
+               *size = 0;
+               return;
+       }
+       glGetActiveUniformsiv(glsl_program_num, 1, &index, GL_UNIFORM_OFFSET, offset);
+       check_error();
+       glGetActiveUniformsiv(glsl_program_num, 1, &index, GL_UNIFORM_SIZE, size);
+       check_error();
+}
+
 void set_uniform_int(GLuint glsl_program_num, const string &prefix, const string &key, int value)
 {
        GLint location = get_uniform_location(glsl_program_num, prefix, key);
index 1a8f04a..e472d23 100644 (file)
@@ -23,6 +23,7 @@ class Node;
 // Note that using EffectChain::register_uniform_*() is more efficient
 // than calling these from set_gl_state().
 GLint get_uniform_location(GLuint glsl_program_num, const std::string &prefix, const std::string &key);
+void get_uniform_offset_and_size(GLuint glsl_program_num, const std::string &prefix, const std::string &key, GLint *offset, GLint *size);
 void set_uniform_int(GLuint glsl_program_num, const std::string &prefix, const std::string &key, int value);
 void set_uniform_float(GLuint glsl_program_num, const std::string &prefix, const std::string &key, float value);
 void set_uniform_vec2(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values);
index 129f493..10c8014 100644 (file)
@@ -1,5 +1,9 @@
 #version 130
 
+// TODO: Make dependent on whether we actually use the feature,
+// and also put in all the headers.
+#extension GL_ARB_uniform_buffer_object : enable
+
 in vec2 tc;
 
 vec4 tex2D(sampler2D s, vec2 coord)