HPPA/HPPA/MultibandRasterRenderer.h

#pragma once

#include "RasterRendererBase.h"
#include "RasterRenderParams.h"
#include <vector>
#include <memory>

class RasterDataProvider;

class MultibandRasterRenderer : public RasterRendererBase
{
public:
    explicit MultibandRasterRenderer(RasterDataProvider* provider);

    QImage render() override;

    // Parameter access
    MultibandRenderParams params() const { return m_params; }
    void setParams(const MultibandRenderParams& params) { m_params = params; }

    void setStretchRatio(float ratio) { m_stretchRatio = ratio; }
    float stretchRatio() const { return m_stretchRatio; }

private:
    MultibandRenderParams m_params;
    float m_stretchRatio = 0.02f;

    // Helper to map float buffer to 8-bit with min/max stretch
    static void stretchTo8bit(const std::vector<float>& in, std::vector<unsigned char>& out, float minVal, float maxVal);

    // Helper to compute histogram from float buffer
    static void computeHistogram(const std::vector<float>& in, std::vector<long>& hist, float& minVal, float& maxVal);

    // Helper to find stretch values by cumulative histogram ratio
    static void findStretchValuesByRatio(const std::vector<long>& hist, float ratio, float& minVal, float& maxVal);

    // Helper to stretch to 8-bit using histogram-based stretch
    static void stretchTo8bitByHistogram(const std::vector<float>& in, std::vector<unsigned char>& out, float minVal, float maxVal);
};