examples/app/fractal/src/FractalView.cpp

Note

This Source File belongs to Fractal Example Example. Please follow the link for example explanation.

/*
 * AUI Framework - Declarative UI toolkit for modern C++20
 * Copyright (C) 2020-2025 Alex2772 and Contributors
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 
//
// Created by alex2772 on 12/9/20.
//
 
#include "FractalView.h"
#include "AUI/Render/IRenderer.h"
#include <glm/gtc/matrix_transform.hpp>
 
static gl::Program::Uniform UNIFORM_TR("tr");
static gl::Program::Uniform UNIFORM_SQ("sq");
static gl::Program::Uniform UNIFORM_RATIO("ratio");
static gl::Program::Uniform UNIFORM_ITERATIONS("iterations");
 
FractalView::FractalView() : mTransform(1.f) {
   setExpanding();
   mShader.load(
       "in vec4 pos;"
       "in vec2 uv;"
       "out vec2 pass_uv;"
       "uniform float ratio;"
       "uniform mat4 SL_uniform_transform;"
 
       "void main() {"
       "gl_Position = SL_uniform_transform * pos;"
       "pass_uv = (uv - 0.5) * 2.0;"
       "pass_uv.x *= ratio;"
       "}",
 
       "in vec2 pass_uv;\n"
 
       "#define product(a, b) dvec2(a.x*b.x-a.y*b.y, a.x*b.y+a.y*b.x)\n"
       "#define conjugate(a) dvec2(a.x,-a.y)\n"
       "#define divide(a, b) dvec2(((a.x*b.x+a.y*b.y)/(b.x*b.x+b.y*b.y)),((a.y*b.x-a.x*b.y)/(b.x*b.x+b.y*b.y)))\n"
       "uniform float c;"
       "uniform int iterations;"
       "uniform dmat4 tr;"
       "uniform sampler2D tex;"
 
       "out vec4 color;"
       "void main() {"
       "dvec2 tmp_pass_uv = (tr * dvec4(pass_uv, 0.0, 1.0)).xy;"
       "dvec2 v = dvec2(0, 0);"
       "int i = 0;"
       "for (; i < iterations; ++i) {"
       "v = product(v, v) + tmp_pass_uv;"
       "dvec2 tmp = v * v;"
       "if ((v.x + v.y) > 4) {"
       "break;"
       "}"
       "}"
       "if (i == iterations) {"
       "color = vec4(0, 0, 0, 1);"
       "} else {"
       "float theta = float(i) / float(iterations);"
       "color = texture(tex, vec2(theta, 0));"
       "}"
       "}",
       { "pos", "uv" }, "400");
   mShader.compile();
   mShader.use();
   mShader.set(UNIFORM_TR, mTransform);
   mShader.set(UNIFORM_SQ, 1.f);
 
   mTexture = _new<gl::Texture2D>();
   mTexture->tex2D(*AImage::fromUrl(":img/color_scheme_wikipedia.png"));
}
 
void FractalView::render(ARenderContext context) {
   AView::render(context);
 
   mShader.use();
   mTexture->bind();
   context.render.rectangle(ACustomShaderBrush {}, { 0, 0 }, getSize());
}
 
void FractalView::setSize(glm::ivec2 size) {
   AView::setSize(size);
   mShader.use();
   mShader.set(UNIFORM_RATIO, mAspectRatio = float(size.x) / float(size.y));
}
 
void FractalView::setIterations(unsigned it) {
   mShader.use();
   mShader.set(UNIFORM_ITERATIONS, int(it));
}
 
void FractalView::onScroll(const AScrollEvent& event) {
   AView::onScroll(event);
   auto projectedPos = (glm::dvec2(event.origin) / glm::dvec2(getSize()) - glm::dvec2(0.5)) * 2.0;
   projectedPos.x *= mAspectRatio;
   mTransform = glm::translate(mTransform, glm::dvec3 { projectedPos, 0.0 });
   mTransform = glm::scale(mTransform, glm::dvec3(1.0 - event.delta.y / 1000.0));
   mTransform = glm::translate(mTransform, -glm::dvec3 { projectedPos, 0.0 });
 
   handleMatrixUpdated();
 
   redraw();
}
 
void FractalView::reset() {
   mTransform = glm::dmat4(1.0);
   handleMatrixUpdated();
   redraw();
}
 
void FractalView::handleMatrixUpdated() {
   mShader.use();
   mShader.set(UNIFORM_TR, mTransform);
   emit centerPosChanged(getPlotPosition(), getPlotScale());
}
 
void FractalView::onKeyDown(AInput::Key key) {
   AView::onKeyDown(key);
   onKeyRepeat(key);
}
 
void FractalView::onKeyRepeat(AInput::Key key) {
   AView::onKeyRepeat(key);
   constexpr float SPEED = 0.2f;
   switch (key) {
       case AInput::UP:
           mTransform = glm::translate(mTransform, { 0, -SPEED, 0 });
           break;
       case AInput::DOWN:
           mTransform = glm::translate(mTransform, { 0, SPEED, 0 });
           break;
       case AInput::LEFT:
           mTransform = glm::translate(mTransform, { -SPEED, 0, 0 });
           break;
       case AInput::RIGHT:
           mTransform = glm::translate(mTransform, { SPEED, 0, 0 });
           break;
       case AInput::PAGEDOWN:
           mTransform = glm::scale(mTransform, glm::dvec3 { 0.99 });
           break;
       case AInput::PAGEUP:
           mTransform = glm::scale(mTransform, glm::dvec3 { 1.01 });
           break;
 
       default:
           return;
   }
   handleMatrixUpdated();
}
 
glm::dvec2 FractalView::getPlotPosition() const { return glm::dvec2(mTransform[3]); }
 
double FractalView::getPlotScale() const { return mTransform[0][0]; }
 
void FractalView::setPlotPositionAndScale(glm::dvec2 position, double scale) {
   mTransform = glm::dmat4(scale);
   mTransform[3] = glm::dvec4 { position, 0, 1 };
   handleMatrixUpdated();
}

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