quantumbloom_tests.cpp

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/**
 * @file quantumbloom_tests.cpp
 * @brief Implements regression and invariant tests for quantumbloom tests.
 * @ingroup qpe_tests
 *
 * Source: @c tests/quantumbloom_tests.cpp. This file is part of Quantum Phenomena Explorer (QPE),
 * maintained by Officina Turini. See LICENSE_IT.txt / LICENSE.txt for the
 * QPE freeware source-available terms and THIRD_PARTY_NOTICES.txt for
 * third-party components.
 */
 
#include "quantumbloom_tests.h"
 
#include "graphics/renderer/quantumbloom.h"
 
#include <cmath>
#include <sstream>
 
namespace qpe {
namespace tests {
 
namespace {
 
/**
 * @brief Performs nearly equal.
 * @param a The a value used by the operation.
 * @param b The b value used by the operation.
 * @param epsilon The epsilon value used by the operation.
 */
bool nearlyEqual(float a, float b, float epsilon = 1.0e-6f)
{
    return std::fabs(a - b) <= epsilon;
}
 
} // namespace
 
/**
 * @brief Runs quantum bloom tests.
 * @param error Output diagnostic text on failure.
 */
bool runQuantumBloomTests(std::string &error)
{
    if (!nearlyEqual(QuantumBloom::clampStrength(-1.0f), 0.0f) ||
        !nearlyEqual(QuantumBloom::clampStrength(2.0f), 2.0f) ||
        !nearlyEqual(QuantumBloom::clampStrength(9.0f), 5.0f)) {
        error = "Bloom strength clamp failed";
        return false;
    }
 
    QuantumBloomSample scene;
    scene.r = 0.20f;
    scene.g = 0.30f;
    scene.b = 0.40f;
 
    QuantumBloomSample glow;
    glow.r = 0.10f;
    glow.g = 0.20f;
    glow.b = 0.30f;
 
    const QuantumBloomSample noBloom = QuantumBloom::combine(scene, glow, 0.0f);
    if (!nearlyEqual(noBloom.r, scene.r) ||
        !nearlyEqual(noBloom.g, scene.g) ||
        !nearlyEqual(noBloom.b, scene.b)) {
        error = "Zero-strength bloom must reproduce the scene exactly";
        return false;
    }
 
    const QuantumBloomSample combined = QuantumBloom::combine(scene, glow, 1.5f);
    if (!nearlyEqual(combined.r, 0.35f) ||
        !nearlyEqual(combined.g, 0.60f) ||
        !nearlyEqual(combined.b, 0.85f)) {
        std::ostringstream stream;
        stream << "Bloom combination failed: "
               << combined.r << ", " << combined.g << ", " << combined.b;
        error = stream.str();
        return false;
    }
 
    // HDR values above one are intentional here; the final Step 6.5 pass tone-maps them.
    QuantumBloomSample hotScene;
    hotScene.r = 0.9f;
    QuantumBloomSample hotGlow;
    hotGlow.r = 0.8f;
    const QuantumBloomSample hdr = QuantumBloom::combine(hotScene, hotGlow, 2.0f);
    if (!(hdr.r > 1.0f)) {
        error = "Bloom composition must preserve HDR values above 1.0";
        return false;
    }
 
    error.clear();
    return true;
}
 
} // namespace tests
} // namespace qpe