|
|
- /*
- * Copyright (C) 2021 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Antkeeper source code is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include "gl/shader-program.hpp"
- #include "gl/shader-object.hpp"
- #include "gl/shader-variable-type.hpp"
- #include "gl/shader-input.hpp"
- #include <glad/glad.h>
- #include <stdexcept>
-
- namespace gl {
-
- shader_program::shader_program():
- gl_program_id(0),
- linked(false)
- {
- // Create an OpenGL shader program
- gl_program_id = glCreateProgram();
-
- // Handle OpenGL errors
- if (!gl_program_id)
- {
- throw std::runtime_error("An error occurred while creating an OpenGL shader program.");
- }
- }
-
- shader_program::~shader_program()
- {
- // Delete shader inputs
- free_inputs();
-
- // Detach all shader objects
- detach_all();
-
- // Delete the OpenGL shader program
- glDeleteProgram(gl_program_id);
- }
-
- void shader_program::attach(const shader_object* object)
- {
- if (attached_objects.find(object) != attached_objects.end())
- {
- throw std::runtime_error("Shader object is already attached to the shader program.");
- }
- else
- {
- // Check that both the OpenGL shader program and OpenGL shader object are valid
- if (glIsProgram(gl_program_id) != GL_TRUE)
- throw std::runtime_error("OpenGL shader program is not a valid program object.");
- if (glIsShader(object->gl_shader_id) != GL_TRUE)
- throw std::runtime_error("OpenGL shader object is not a valid shader object.");
-
- // Attach the OpenGL shader object to the OpenGL shader program
- glAttachShader(gl_program_id, object->gl_shader_id);
-
- // Handle OpenGL errors
- switch (glGetError())
- {
- case GL_INVALID_OPERATION:
- throw std::runtime_error("OpenGL shader object is already attached to the shader program.");
- break;
- }
-
- // Add shader object to set of attached objects
- attached_objects.insert(object);
- }
- }
-
- void shader_program::detach(const shader_object* object)
- {
- if (attached_objects.find(object) == attached_objects.end())
- {
- throw std::runtime_error("Shader object is not attached to the shader program.");
- }
- else
- {
- // Check that both the OpenGL shader program and OpenGL shader object are valid
- if (glIsProgram(gl_program_id) != GL_TRUE)
- throw std::runtime_error("OpenGL shader program is not a valid program object.");
- if (glIsShader(object->gl_shader_id) != GL_TRUE)
- throw std::runtime_error("OpenGL shader object is not a valid shader object.");
-
- // Detach the OpenGL shader object from the OpenGL shader program
- glDetachShader(gl_program_id, object->gl_shader_id);
-
- // Handle OpenGL errors
- switch (glGetError())
- {
- case GL_INVALID_OPERATION:
- throw std::runtime_error("OpenGL shader object is not attached to the shader program.");
- break;
- }
-
- // Remove shader object from set of attached objects
- attached_objects.erase(object);
- }
- }
-
- void shader_program::detach_all()
- {
- while (!attached_objects.empty())
- detach(*attached_objects.begin());
- }
-
- bool shader_program::link()
- {
- // Check that the OpenGL shader program is valid
- if (glIsProgram(gl_program_id) != GL_TRUE)
- throw std::runtime_error("OpenGL shader program is not a valid program object.");
-
- // Link OpenGL shader program
- glLinkProgram(gl_program_id);
-
- // Handle OpenGL errors
- switch (glGetError())
- {
- case GL_INVALID_OPERATION:
- throw std::runtime_error("OpenGL shader program is the currently active program object and transform feedback mode is active.");
- break;
- }
-
- // Get OpenGL shader program linking status
- GLint gl_link_status;
- glGetProgramiv(gl_program_id, GL_LINK_STATUS, &gl_link_status);
- linked = (gl_link_status == GL_TRUE);
-
- // Get OpenGL shader program info log length
- GLint gl_info_log_length;
- glGetProgramiv(gl_program_id, GL_INFO_LOG_LENGTH, &gl_info_log_length);
-
- if (gl_info_log_length > 0)
- {
- // Resize string to accommodate OpenGL shader program info log
- info_log.resize(gl_info_log_length);
-
- // Read OpenGL shader program info log into string
- glGetProgramInfoLog(gl_program_id, gl_info_log_length, &gl_info_log_length, info_log.data());
-
- // Remove redundant null terminator from string
- info_log.pop_back();
- }
- else
- {
- // Empty info log
- info_log.clear();
- }
-
- // Find shader inputs
- find_inputs();
-
- return linked;
- }
-
- void shader_program::find_inputs()
- {
- // Get maximum uniform name length
- GLint max_uniform_name_length = 0;
- glGetProgramiv(gl_program_id, GL_ACTIVE_UNIFORM_MAX_LENGTH, &max_uniform_name_length);
-
- // Allocate uniform name buffer
- GLchar* uniform_name = new GLchar[max_uniform_name_length];
-
- // Get number of active uniforms in the shader
- GLint active_uniform_count = 0;
- glGetProgramiv(gl_program_id, GL_ACTIVE_UNIFORMS, &active_uniform_count);
-
- // Set first available texture unit
- int available_texture_unit = 0;
-
- // For each active uniform
- for (GLuint uniform_index = 0; uniform_index < static_cast<GLuint>(active_uniform_count); ++uniform_index)
- {
- // Get information about uniform
- GLsizei uniform_name_length;
- GLint uniform_size;
- GLenum uniform_type;
- glGetActiveUniform(gl_program_id, uniform_index, static_cast<GLsizei>(max_uniform_name_length), &uniform_name_length, &uniform_size, &uniform_type, &uniform_name[0]);
-
- // Get name without array symbols
- std::string input_name = uniform_name;
- std::size_t bracketPos = input_name.find_first_of("[");
- if (bracketPos != std::string::npos)
- {
- input_name = input_name.substr(0, bracketPos);
- }
-
- // Determine corresponding shader variable data type
- shader_variable_type variable_type;
- int texture_unit = -1;
- bool unsupported = false;
- switch (uniform_type)
- {
- case GL_BOOL:
- variable_type = shader_variable_type::bool1;
- break;
- case GL_BOOL_VEC2:
- variable_type = shader_variable_type::bool2;
- break;
- case GL_BOOL_VEC3:
- variable_type = shader_variable_type::bool3;
- break;
- case GL_BOOL_VEC4:
- variable_type = shader_variable_type::bool4;
- break;
-
- case GL_INT:
- variable_type = shader_variable_type::int1;
- break;
- case GL_INT_VEC2:
- variable_type = shader_variable_type::int2;
- break;
- case GL_INT_VEC3:
- variable_type = shader_variable_type::int3;
- break;
- case GL_INT_VEC4:
- variable_type = shader_variable_type::int4;
- break;
-
- case GL_UNSIGNED_INT:
- variable_type = shader_variable_type::uint1;
- break;
- case GL_UNSIGNED_INT_VEC2:
- variable_type = shader_variable_type::uint2;
- break;
- case GL_UNSIGNED_INT_VEC3:
- variable_type = shader_variable_type::uint3;
- break;
- case GL_UNSIGNED_INT_VEC4:
- variable_type = shader_variable_type::uint4;
- break;
-
- case GL_FLOAT:
- variable_type = shader_variable_type::float1;
- break;
- case GL_FLOAT_VEC2:
- variable_type = shader_variable_type::float2;
- break;
- case GL_FLOAT_VEC3:
- variable_type = shader_variable_type::float3;
- break;
- case GL_FLOAT_VEC4:
- variable_type = shader_variable_type::float4;
- break;
-
- case GL_FLOAT_MAT2:
- variable_type = shader_variable_type::float2x2;
- break;
- case GL_FLOAT_MAT3:
- variable_type = shader_variable_type::float3x3;
- break;
- case GL_FLOAT_MAT4:
- variable_type = shader_variable_type::float4x4;
- break;
-
- case GL_SAMPLER_1D:
- case GL_SAMPLER_1D_SHADOW:
- variable_type = shader_variable_type::texture_1d;
- texture_unit = available_texture_unit;
- available_texture_unit += uniform_size;
- break;
-
- case GL_SAMPLER_2D:
- case GL_SAMPLER_2D_SHADOW:
- variable_type = shader_variable_type::texture_2d;
- texture_unit = available_texture_unit;
- available_texture_unit += uniform_size;
- break;
-
- case GL_SAMPLER_3D:
- variable_type = shader_variable_type::texture_3d;
- texture_unit = available_texture_unit;
- available_texture_unit += uniform_size;
- break;
-
- case GL_SAMPLER_CUBE:
- variable_type = shader_variable_type::texture_cube;
- texture_unit = available_texture_unit;
- available_texture_unit += uniform_size;
- break;
-
- default:
- unsupported = true;
- break;
- }
-
- // Check if data type is supported
- if (unsupported)
- {
- std::string message = std::string("Shader uniform \"") + std::string(uniform_name) + std::string("\" has unsupported data type.");
- throw std::runtime_error(message.c_str());
- }
-
- // Get uniform location
- GLint uniform_location = glGetUniformLocation(gl_program_id, uniform_name);
- if (uniform_location == -1)
- {
- //std::string message = std::string("Unable to get location for uniform \"") + std::string(uniform_name) + std::string("\"");
- //throw std::runtime_error(message.c_str());
- }
- else
- {
- // Create new shader input
- shader_input* input = new shader_input(this, inputs.size(), uniform_location, input_name, variable_type, uniform_size, texture_unit);
- input_map[input_name] = input;
- inputs.push_back(input);
- }
- }
-
- // Free uniform name buffer
- delete[] uniform_name;
- }
-
- void shader_program::free_inputs()
- {
- for (shader_input* input: inputs)
- {
- delete input;
- }
-
- inputs.clear();
- }
-
- } // namespace gl
|