/*
* <Short Description>
* Copyright (C) 2023 Brett Terpstra
*
* This program 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.
*
* This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <blt/gfx/renderer/batch_2d_renderer.h>
#include <blt/gfx/renderer/2d_textured.vert>
#include <blt/gfx/renderer/2d_line.vert>
#include <blt/gfx/renderer/2d_textured.frag>
#include <blt/gfx/renderer/2d_textured_circle.frag>
#include <blt/gfx/renderer/2d_line.frag>
// https://stackoverflow.com/questions/60440682/drawing-a-line-in-modern-opengl
float square_vertices[20] = {
// positions // texture coords
0.5f, 0.5f, 0.0f, 1.0f, 1.0f, // top right
0.5f, -0.5f, 0.0f, 1.0f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f, 0.0f, 1.0f // top left
};
const unsigned int square_indices[6] = {
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
float line_vertices[20] = {
// positions // texture coords
0.5f, 0.5f, 0.0f, 1.0f, 1.0f, // top right
0.5f, -0.5f, 0.0f, 1.0f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f, 0.0f, 1.0f // top left
};
// 0, 1 (top right)
// 5, 6 (bottom right)
// 10, 11 (bottom left)
// 15, 16 (top left)
namespace blt::gfx
{
void batch_renderer_2d::create()
{
{
vbo_t vertices_vbo;
ebo_t indices_vbo;
vertices_vbo.create();
indices_vbo.create();
vertices_vbo.allocate(sizeof(square_vertices), square_vertices);
indices_vbo.allocate(sizeof(square_indices), square_indices);
square_vao = new vertex_array();
auto tb = square_vao->bindVBO(vertices_vbo, 0, 3, GL_FLOAT, 5 * sizeof(float), 0);
square_vao->bindVBO(tb, 1, 2, GL_FLOAT, 5 * sizeof(float), 3 * sizeof(float));
square_vao->bindElement(indices_vbo);
}
{
vbo_t vertices_vbo;
ebo_t indices_vbo;
vertices_vbo.create();
indices_vbo.create();
vertices_vbo.allocate(sizeof(line_vertices), line_vertices);
indices_vbo.allocate(sizeof(square_indices), square_indices);
line_vao = new vertex_array();
auto tb = line_vao->bindVBO(vertices_vbo, 0, 3, GL_FLOAT, 5 * sizeof(float), 0);
line_vao->bindVBO(tb, 1, 2, GL_FLOAT, 5 * sizeof(float), 3 * sizeof(float));
line_vao->bindElement(indices_vbo);
}
square_shader = new shader_t(shader_2d_textured_vert, shader_2d_textured_frag);
square_shader->bindAttribute(0, "vertex");
square_shader->bindAttribute(1, "uv_in");
point_shader = new shader_t(shader_2d_textured_vert, shader_2d_textured_cirlce_frag);
point_shader->bindAttribute(0, "vertex");
point_shader->bindAttribute(1, "uv_in");
}
void batch_renderer_2d::cleanup()
{
delete square_vao;
delete square_shader;
delete point_shader;
}
template<typename T>
void find_min_and_max(T& container, blt::f32& min, blt::f32& max)
{
for (auto& textures : container)
{
for (auto& colors : textures.second)
{
for (auto& blend_factors : colors.second)
{
for (auto& obj : blend_factors.second)
{
min = std::min(min, obj.z_index);
max = std::max(max, obj.z_index);
}
}
}
}
}
void batch_renderer_2d::render(bool transparency)
{
if (transparency)
{
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
glEnable(GL_DEPTH_TEST);
draw_count_ = 0;
square_shader->bind();
square_vao->bind();
glActiveTexture(GL_TEXTURE0);
// annoying
blt::f32 min = std::numeric_limits<blt::f32>::max();
blt::f32 max = std::numeric_limits<blt::f32>::min();
find_min_and_max(complex_rectangles, min, max);
find_min_and_max(complex_points, min, max);
find_min_and_max(complex_lines, min, max);
blt::f32 denominator = 1.0f / (max - min);
for (auto& textures : complex_rectangles)
{
// resource manager handles the check for empty string
if (auto val = resources.get(textures.first))
val.value()->bind();
for (auto& colors : textures.second)
{
square_shader->setVec4("color", colors.first);
for (auto& blend_factors : colors.second)
{
square_shader->setVec4("use_texture", blend_factors.first);
for (auto& rect_obj : blend_factors.second)
{
auto& rect = rect_obj.obj;
blt::mat4x4 model;
model.translate(rect.pos.x(), rect.pos.y(), 0.0f);
model.scale(rect.size.x(), rect.size.y(), 1);
if (rect.rotation != 0)
model.rotateZ(blt::toRadians(rect.rotation));
square_shader->setMatrix("model", model);
square_shader->setFloat("z_index", (rect_obj.z_index - min) * denominator);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
draw_count_++;
}
blend_factors.second.clear();
}
colors.second.clear();
}
textures.second.clear();
}
point_shader->bind();
for (auto& textures : complex_points)
{
// resource manager handles the check for empty string
if (auto val = resources.get(textures.first))
val.value()->bind();
for (auto& colors : textures.second)
{
point_shader->setVec4("color", colors.first);
for (auto& blend_factors : colors.second)
{
point_shader->setVec4("use_texture", blend_factors.first);
for (auto& point_obj : blend_factors.second)
{
auto& point = point_obj.obj;
blt::mat4x4 model;
model.translate(point.pos.x(), point.pos.y(), 0.0f);
model.scale(point.scale, point.scale, 1);
point_shader->setMatrix("model", model);
point_shader->setFloat("z_index", (point_obj.z_index - min) * denominator);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
draw_count_++;
}
blend_factors.second.clear();
}
colors.second.clear();
}
textures.second.clear();
}
blt::mat4x4 model;
square_shader->bind();
square_shader->setMatrix("model", model);
line_vao->bind();
auto& buf = line_vao->getBuffer(0);
buf.bind();
for (auto& textures : complex_lines)
{
// resource manager handles the check for empty string
if (auto val = resources.get(textures.first))
val.value()->bind();
for (auto& colors : textures.second)
{
square_shader->setVec4("color", colors.first);
for (auto& blend_factors : colors.second)
{
square_shader->setVec4("use_texture", blend_factors.first);
for (auto& line_obj : blend_factors.second)
{
auto& line = line_obj.obj;
// 0, 1 (top right)
// 5, 6 (bottom right)
// 10, 11 (bottom left)
// 15, 16 (top left)
blt::vec2 dir = (line.p1 - line.p2).normalize();
blt::vec2 right = {dir.y(), -dir.x()};
blt::vec2 left = {-dir.y(), dir.x()};
auto bottom_left = line.p1 + left * line.thickness;
auto bottom_right = line.p1 + right * line.thickness;
auto top_left = line.p2 + left * line.thickness;
auto top_right = line.p2 + right * line.thickness;
line_vertices[0] = top_right.x();
line_vertices[1] = top_right.y();
line_vertices[5] = bottom_right.x();
line_vertices[6] = bottom_right.y();
line_vertices[10] = bottom_left.x();
line_vertices[11] = bottom_left.y();
line_vertices[15] = top_left.x();
line_vertices[16] = top_left.y();
buf.update(sizeof(line_vertices), line_vertices);
square_shader->setFloat("z_index", (line_obj.z_index - min) * denominator);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
draw_count_++;
}
blend_factors.second.clear();
}
colors.second.clear();
}
textures.second.clear();
}
glDisable(GL_DEPTH_TEST);
if (transparency)
glDisable(GL_BLEND);
}
}