- /*
- * Copyright (C) 2023 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 <engine/render/passes/bloom-pass.hpp>
- #include <engine/resources/resource-manager.hpp>
- #include <engine/gl/pipeline.hpp>
- #include <engine/gl/framebuffer.hpp>
- #include <engine/gl/shader-program.hpp>
- #include <engine/gl/shader-variable.hpp>
- #include <engine/gl/vertex-buffer.hpp>
- #include <engine/gl/vertex-array.hpp>
- #include <engine/gl/texture.hpp>
- #include <engine/render/vertex-attribute-location.hpp>
- #include <engine/render/context.hpp>
- #include <algorithm>
- #include <cmath>
-
- namespace render {
-
- bloom_pass::bloom_pass(gl::pipeline* pipeline, resource_manager* resource_manager):
- pass(pipeline, nullptr)
- {
- // Load downsample shader template
- auto downsample_shader_template = resource_manager->load<gl::shader_template>("bloom-downsample.glsl");
-
- // Build downsample shader program with Karis averaging
- m_downsample_karis_shader = downsample_shader_template->build
- (
- {
- {"KARIS_AVERAGE", std::string()}
- }
- );
-
- // Build downsample shader program without Karis averaging
- m_downsample_shader = downsample_shader_template->build();
-
- // Load upsample shader template
- auto upsample_shader_template = resource_manager->load<gl::shader_template>("bloom-upsample.glsl");
-
- // Build upsample shader program
- m_upsample_shader = upsample_shader_template->build();
-
- // Construct framebuffer texture sampler
- m_sampler = std::make_shared<gl::sampler>
- (
- gl::sampler_filter::linear,
- gl::sampler_filter::linear,
- gl::sampler_mipmap_mode::linear,
- gl::sampler_address_mode::clamp_to_edge,
- gl::sampler_address_mode::clamp_to_edge
- );
-
- // Allocate empty vertex array
- m_vertex_array = std::make_unique<gl::vertex_array>();
- }
-
- void bloom_pass::render(render::context& ctx)
- {
- // Execute command buffer
- for (const auto& command: m_command_buffer)
- {
- command();
- }
- }
-
- void bloom_pass::set_source_texture(std::shared_ptr<gl::texture_2d> texture)
- {
- if (m_source_texture != texture)
- {
- m_source_texture = texture;
-
- rebuild_mip_chain();
- correct_filter_radius();
- rebuild_command_buffer();
- }
- }
-
- void bloom_pass::set_mip_chain_length(unsigned int length)
- {
- m_mip_chain_length = length;
- rebuild_mip_chain();
- rebuild_command_buffer();
- }
-
- void bloom_pass::set_filter_radius(float radius)
- {
- m_filter_radius = radius;
- correct_filter_radius();
- }
-
- void bloom_pass::rebuild_mip_chain()
- {
- if (m_source_texture && m_mip_chain_length)
- {
- // Rebuild target image
- m_target_image = std::make_shared<gl::image_2d>
- (
- gl::format::r16g16b16_sfloat,
- m_source_texture->get_image_view()->get_image()->get_dimensions()[0],
- m_source_texture->get_image_view()->get_image()->get_dimensions()[1],
- m_mip_chain_length
- );
-
- m_target_textures.resize(m_mip_chain_length);
- m_target_framebuffers.resize(m_mip_chain_length);
- for (unsigned int i = 0; i < m_mip_chain_length; ++i)
- {
- // Rebuild mip texture
- m_target_textures[i] = std::make_shared<gl::texture_2d>
- (
- std::make_shared<gl::image_view_2d>
- (
- m_target_image,
- m_target_image->get_format(),
- i,
- 1
- ),
- m_sampler
- );
-
- // Rebuild mip framebuffer
- const gl::framebuffer_attachment attachments[1] =
- {{
- gl::color_attachment_bit,
- m_target_textures[i]->get_image_view(),
- 0
- }};
- m_target_framebuffers[i] = std::make_shared<gl::framebuffer>
- (
- attachments,
- m_target_image->get_dimensions()[0] >> i,
- m_target_image->get_dimensions()[1] >> i
- );
- }
- }
- else
- {
- m_target_image = nullptr;
- m_target_textures.clear();
- m_target_framebuffers.clear();
- }
- }
-
- void bloom_pass::correct_filter_radius()
- {
- // Get aspect ratio of target image
- float aspect_ratio = 1.0f;
- if (m_target_image)
- {
- aspect_ratio = static_cast<float>(m_target_image->get_dimensions()[1]) /
- static_cast<float>(m_target_image->get_dimensions()[0]);
- }
-
- // Correct filter radius according to target image aspect ratio
- m_corrected_filter_radius = {m_filter_radius * aspect_ratio, m_filter_radius};
- }
-
- void bloom_pass::rebuild_command_buffer()
- {
- m_command_buffer.clear();
-
- if (!m_source_texture ||
- !m_mip_chain_length ||
- !m_downsample_karis_shader ||
- !m_downsample_shader ||
- !m_upsample_shader)
- {
- return;
- }
-
- // Setup downsample state
- m_command_buffer.emplace_back
- (
- [&]()
- {
- m_pipeline->set_primitive_topology(gl::primitive_topology::triangle_list);
- m_pipeline->bind_vertex_array(m_vertex_array.get());
- m_pipeline->set_depth_test_enabled(false);
- m_pipeline->set_cull_mode(gl::cull_mode::back);
- m_pipeline->set_color_blend_enabled(false);
- }
- );
-
- // Downsample first mip with Karis average
- if (auto source_texture_var = m_downsample_karis_shader->variable("source_texture"))
- {
- m_command_buffer.emplace_back
- (
- [&, source_texture_var]()
- {
- m_pipeline->bind_shader_program(m_downsample_karis_shader.get());
- m_pipeline->bind_framebuffer(m_target_framebuffers[0].get());
-
- const auto& target_dimensions = m_target_image->get_dimensions();
- const gl::viewport viewport[1] = {{0.0f, 0.0f, static_cast<float>(target_dimensions[0]), static_cast<float>(target_dimensions[1])}};
- m_pipeline->set_viewport(0, viewport);
-
- source_texture_var->update(*m_source_texture);
-
- // Draw fullscreen triangle
- m_pipeline->draw(3, 1, 0, 0);
- }
- );
- }
-
- // Downsample remaining mips
- if (m_mip_chain_length > 1)
- {
- if (auto source_texture_var = m_downsample_shader->variable("source_texture"))
- {
- m_command_buffer.emplace_back([&](){m_pipeline->bind_shader_program(m_downsample_shader.get());});
-
- for (int i = 1; i < static_cast<int>(m_mip_chain_length); ++i)
- {
- m_command_buffer.emplace_back
- (
- [&, source_texture_var, i]()
- {
- m_pipeline->bind_framebuffer(m_target_framebuffers[i].get());
-
- const auto& target_dimensions = m_target_image->get_dimensions();
- const gl::viewport viewport[1] = {{0.0f, 0.0f, static_cast<float>(target_dimensions[0] >> i), static_cast<float>(target_dimensions[1] >> i)}};
- m_pipeline->set_viewport(0, viewport);
-
- // Use previous downsample texture as downsample source
- source_texture_var->update(*m_target_textures[i - 1]);
-
- // Draw fullscreen triangle
- m_pipeline->draw(3, 1, 0, 0);
- }
- );
- }
- }
- }
-
- // Setup upsample state
- m_command_buffer.emplace_back
- (
- [&]()
- {
- // Enable additive blending
- m_pipeline->set_color_blend_enabled(true);
- m_pipeline->set_color_blend_equation
- ({
- gl::blend_factor::one,
- gl::blend_factor::one,
- gl::blend_op::add,
- gl::blend_factor::one,
- gl::blend_factor::one,
- gl::blend_op::add
- });
-
- // Bind upsample shader
- m_pipeline->bind_shader_program(m_upsample_shader.get());
- }
- );
-
- // Update upsample filter radius
- if (auto filter_radius_var = m_upsample_shader->variable("filter_radius"))
- {
- m_command_buffer.emplace_back([&, filter_radius_var](){filter_radius_var->update(m_corrected_filter_radius);});
- }
-
- // Upsample
- if (auto source_texture_var = m_upsample_shader->variable("source_texture"))
- {
- for (int i = static_cast<int>(m_mip_chain_length) - 1; i > 0; --i)
- {
- const int j = i - 1;
-
- m_command_buffer.emplace_back
- (
- [&, source_texture_var, i, j]()
- {
- m_pipeline->bind_framebuffer(m_target_framebuffers[j].get());
-
- const auto& target_dimensions = m_target_image->get_dimensions();
- const gl::viewport viewport[1] = {{0.0f, 0.0f, static_cast<float>(target_dimensions[0] >> j), static_cast<float>(target_dimensions[1] >> j)}};
- m_pipeline->set_viewport(0, viewport);
-
- source_texture_var->update(*m_target_textures[i]);
-
- // Draw fullscreen triangle
- m_pipeline->draw(3, 1, 0, 0);
- }
- );
- }
- }
- }
-
- } // namespace render
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