Initial commit

code/rt_weekend.cpp

@@ -0,0 +1,50 @@
+#include "rt_weekend.h"
+#include "ray.h"
+
+bool hit_sphere(const vec3& center, float radius, const ray& r)
+{
+    vec3 oc = r.origin() - center;
+    float a = dot(r.direction(), r.direction());
+    float b = 2.0 * dot(oc, r.direction());
+    float c = dot(oc, oc) - radius * radius;
+    float discriminant = b * b - 4 * a * c;
+    return (discriminant > 0);
+}
+
+vec3 color(const ray& r)
+{
+    if (hit_sphere(vec3(0, 0, -1), 0.5, r))
+        return vec3(1, 0, 0);
+    vec3 unit_direction = unit_vector(r.direction());
+    float t = 0.5 * (unit_direction.y() + 1.0);
+    return (1.0 - t) * vec3(1.0, 1.0, 1.0) + t * vec3(0.5, 0.7, 1.0);
+}
+
+extern "C"
+void
+PluginUpdateAndRender(plugin_offscreen_buffer *Buffer)
+{
+    int Pitch = Buffer->Pitch;
+    uint8_t *Row = (uint8_t *)Buffer->Memory;
+    for(int Y = 0;
+        Y < Buffer->Height;
+        ++Y)
+    {
+        uint32_t *Pixel = (uint32_t *)Row;
+        for(int X = 0;
+            X < Buffer->Width;
+            ++X)
+        {
+            float r = float(X) / float(Buffer->Width);
+            float g = float(Y) / float(Buffer->Height);
+            float b = 0.2;
+            int ir = int(255.99 * r);
+            int ig = int(255.99 * g);
+            int ib = int(255.99 * b);
+
+            *Pixel++ = (ir << 24) + (ig << 16) + (ib << 8) + 0xFF;
+        }
+
+        Row += Pitch;
+    }
+}