Canvas implementation and add build of LodePNG

source/canvas.cpp

@@ -0,0 +1,57 @@
+/*
+ *  DoRayMe - a quick and dirty Raytracer
+ *  Canvas implementation
+ *
+ *  Created by Manoël Trapier
+ *  Copyright (c) 2020 986-Studio.
+ *
+ */
+
+#include <canvas.h>
+#include <lodepng.h>
+
+#define BPP (24)
+#define BytePP (BPP / 8)
+
+#define MIN(_a, _b) ((_a)<(_b)?(_a):(_b))
+#define MAX(_a, _b) ((_a)>(_b)?(_a):(_b))
+
+Canvas::Canvas(uint32_t width, uint32_t height) : width(width), height(height)
+{
+    this->bitmap = (uint8_t *)calloc(4, width * height);
+    this->stride = BytePP * width;
+}
+
+Canvas::~Canvas()
+{
+    if (this->bitmap != nullptr)
+    {
+        free(this->bitmap);
+    }
+}
+
+void Canvas::put_pixel(uint32_t x, uint32_t y, Colour c)
+{
+    uint32_t offset = y * this->stride + x * BytePP;
+    this->bitmap[offset + 0] = MAX(MIN(c.red() * 255, 255), 0);
+    this->bitmap[offset + 1] = MAX(MIN(c.green() * 255, 255), 0);
+    this->bitmap[offset + 2] = MAX(MIN(c.blue() * 255, 255), 0);
+}
+
+Colour Canvas::get_pixel(uint32_t x, uint32_t y)
+{
+    uint32_t offset = y * this->stride + x * BytePP;
+    return Colour(this->bitmap[offset + 0] / 255, this->bitmap[offset + 1] / 255, this->bitmap[offset + 2] / 255);
+}
+
+bool Canvas::SaveAsPNG(const char *filename)
+{
+    uint32_t ret = lodepng_encode24_file(filename, this->bitmap, this->width, this->height);
+
+    if (ret > 0)
+    {
+        printf("lodepng_encode_file returned %d!\n", ret);
+    }
+
+    return ret == 0;
+}