From 8f7f527732e30a4b35250bb5696bd55418d69f67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Du=C5=A1an=20Poizl?= <nou.spiro@gmail.com>
Date: Tue, 29 Oct 2024 19:42:36 +0100
Subject: [PATCH] Add RawImage::convertToType()

---
 rawimage.cpp | 129 +++++++++++++++++++++++++++++++++++++--------------
 rawimage.h   |   1 +
 2 files changed, 96 insertions(+), 34 deletions(-)

diff --git a/rawimage.cpp b/rawimage.cpp
index 3695a4d..c36b669 100644
--- a/rawimage.cpp
+++ b/rawimage.cpp
@@ -435,45 +435,106 @@ void RawImage::convertToThumbnail()
 
 void RawImage::convertToGLFormat()
 {
-    size_t s = size() * m_ch;
-    if(m_type == UINT32)
-    {
-        m_origWidth = m_width;
-        m_origHeight = m_height;
-        m_original = std::move(m_pixels);
-        allocate(m_width, m_height, m_channels, FLOAT32);
-        m_origType = UINT32;
-        float *dst = reinterpret_cast<float*>(m_pixels.get());
-        uint32_t *src = reinterpret_cast<uint32_t*>(m_original.get());
+    if(m_type == UINT32 || m_type == FLOAT64)
+        convertToType(FLOAT32);
+    else if(OpenGLES && m_type == UINT16)
+        convertToType(FLOAT16);
+}
 
-        for(size_t i = 0; i < s; i++)
-            dst[i] = src[i] / (float)UINT32_MAX;
-    }
-    else if(m_type == FLOAT64)
+template<typename T, typename U>
+void convertType2(uint32_t size, const T *src, U *dst)
+{
+    if constexpr((std::is_floating_point_v<T> || std::is_same_v<T, F16>) && (std::is_floating_point_v<U> || std::is_same_v<T, F16>))
     {
-        m_origWidth = m_width;
-        m_origHeight = m_height;
-        m_original = std::move(m_pixels);
-        allocate(m_width, m_height, m_channels, FLOAT32);
-        m_origType = FLOAT64;
-        float *dst = reinterpret_cast<float*>(m_pixels.get());
-        double *src = reinterpret_cast<double*>(m_original.get());
-
-        for(size_t i = 0; i < s; i++)
+        for(uint32_t i = 0; i < size; i++)
             dst[i] = src[i];
     }
-    else if(OpenGLES && m_type == UINT16)
-    {
-        m_origWidth = m_width;
-        m_origHeight = m_height;
-        m_original = std::move(m_pixels);
-        allocate(m_width, m_height, m_channels, FLOAT16);
-        m_origType = UINT16;
-        F16 *dst = reinterpret_cast<F16*>(m_pixels.get());
-        uint16_t *src = reinterpret_cast<uint16_t*>(m_original.get());
 
-        for(size_t i = 0; i < s; i++)
-            dst[i] = (F16)(src[i] / (float)UINT16_MAX);
+    if constexpr(std::is_integral_v<T> && std::is_integral_v<U>)
+    {
+        if constexpr(sizeof(T) > sizeof(U))
+            for(uint32_t i = 0; i < size; i++)
+                dst[i] = src[i] >> ((sizeof(T) - sizeof(U)) * 8);
+        else
+            for(uint32_t i = 0; i < size; i++)
+                dst[i] = static_cast<U>(src[i]) << ((sizeof(U) - sizeof(T)) * 8);
+    }
+
+    if constexpr((std::is_floating_point_v<T> || std::is_same_v<T, F16>) && std::is_integral_v<U>)
+    {
+        U max = std::numeric_limits<U>::max();
+        T scale = (T)(max);
+        for(uint32_t i = 0; i < size; i++)
+            dst[i] = src[i] * scale;
+    }
+
+    if constexpr(std::is_integral_v<T> && (std::is_floating_point_v<U> || std::is_same_v<U, F16>))
+    {
+        U scale = 1.0 / std::numeric_limits<T>::max();
+        for(uint32_t i = 0; i < size; i++)
+            dst[i] = (U)src[i] * scale;
+    }
+}
+
+template<typename T>
+void convertType(uint32_t size, RawImage::DataType dstType, const T *src, void *dst)
+{
+    switch(dstType)
+    {
+    case RawImage::UINT8:
+        convertType2(size, src, static_cast<uint8_t*>(dst));
+        break;
+    case RawImage::UINT16:
+        convertType2(size, src, static_cast<uint16_t*>(dst));
+        break;
+    case RawImage::UINT32:
+        convertType2(size, src, static_cast<uint32_t*>(dst));
+        break;
+    case RawImage::FLOAT16:
+        convertType2(size, src, static_cast<F16*>(dst));
+        break;
+    case RawImage::FLOAT32:
+        convertType2(size, src, static_cast<float*>(dst));
+        break;
+    case RawImage::FLOAT64:
+        convertType2(size, src, static_cast<double*>(dst));
+        break;
+    }
+}
+
+void RawImage::convertToType(DataType type)
+{
+    if(type == m_type)
+        return;
+
+    m_origWidth = m_width;
+    m_origHeight = m_height;
+    m_original = std::move(m_pixels);
+    DataType origType = m_type;
+    allocate(m_width, m_height, m_channels, type);
+    m_origType = origType;
+
+    uint32_t s = size() * m_ch;
+    switch(m_origType)
+    {
+    case UINT8:
+        convertType(s, type, reinterpret_cast<uint8_t*>(m_original.get()), m_pixels.get());
+        break;
+    case UINT16:
+        convertType(s, type, reinterpret_cast<uint16_t*>(m_original.get()), m_pixels.get());
+        break;
+    case UINT32:
+        convertType(s, type, reinterpret_cast<uint32_t*>(m_original.get()), m_pixels.get());
+        break;
+    case FLOAT16:
+        convertType(s, type, reinterpret_cast<F16*>(m_original.get()), m_pixels.get());
+        break;
+    case FLOAT32:
+        convertType(s, type, reinterpret_cast<float*>(m_original.get()), m_pixels.get());
+        break;
+    case FLOAT64:
+        convertType(s, type, reinterpret_cast<double*>(m_original.get()), m_pixels.get());
+        break;
     }
 }
 
diff --git a/rawimage.h b/rawimage.h
index 26c10dd..c565025 100644
--- a/rawimage.h
+++ b/rawimage.h
@@ -103,6 +103,7 @@ public:
     void setPlanar();
     void convertToThumbnail();
     void convertToGLFormat();
+    void convertToType(RawImage::DataType type);
     float thumbAspect() const;
     bool pixel(int x, int y, double &r, double &g, double &b) const;
     void resize(uint32_t w, uint32_t h);