feat: add cube and rotation

src/main.c

@@ -1,33 +1,73 @@
-#include <stdio.h>
-#include "cam.h"
-#include "draw.h"
 #include "math/mv4.h"
+#include "draw.h"
+#include "cam.h"
+#include "sleepms.h"
 
-int main(int argc, const char** argv)
+
+Vec4f_t cubeVertices[8] = {
+    { -1,-1,-1,1 }, { 1,-1,-1,1 },
+    { 1, 1,-1,1 }, { -1, 1,-1,1 },
+    { -1,-1, 1,1 }, { 1,-1, 1,1 },
+    { 1, 1, 1,1 }, { -1, 1, 1,1 }
+};
+
+int cubeEdges[12][2] = {
+    {0,1}, {1,2}, {2,3}, {3,0},
+    {4,5}, {5,6}, {6,7}, {7,4},
+    {0,4}, {1,5}, {2,6}, {3,7}
+};
+
+int main() 
 {
-    const float fov = 60;
-    const float width = 80, height = 30;
-    const float near = 0.1, far = 1000;
+    const float fov = 60.f;
+    const int width = 120, height = 40;
+    const float near = 0.1f, far = 1000.f;
+    const float aspect = (float)width / (float)height;
 
-    const float aspect = width / height;
+    Vec4f_t eye = vec4f(0.f, 0.f, 15.f, 1.f);
+    Vec4f_t center = vec4f(0.f, 0.f, 0.f, 1.f);
+    Vec4f_t up = vec4f(0.f, 1.f, 0.f, 0.f);
 
+    Mat4f_t view = lookAt(&eye, &center, &up);
     Mat4f_t proj = perspCam(fov, aspect, near, far);
 
-    // xyz = [-1; 1]
-    Vec4f_t vec0 = vec4f(0.f, 0.f, -1.f, 1.f);
-    Vec4f_t v_clip0 = mat4f_mul_vec4f(proj, vec0);
-    normCoord_r(&v_clip0);
-    viewport_r(&v_clip0, width, height);
-
-    Vec4f_t vec1 = vec4f(0.f, 0.6f, -1.f, 1.f);
-    Vec4f_t v_clip1 = mat4f_mul_vec4f(proj, vec1);
-    normCoord_r(&v_clip1);
-    viewport_r(&v_clip1, width, height);
+    float angle = 0.f;
 
     initCanvas(width, height);
-    // drawCanvas(v_clip, width, height);
-    drawLine(v_clip0, v_clip1, width, height);
-    renderCanvas(width, height);
+    
+    while (1) {
+        clearCanvas(width, height);
+
+        Mat4f_t rx = rotateX(angle);
+        Mat4f_t ry = rotateY(angle);
+        Mat4f_t rz = rotateZ(angle);
+
+        mat4f_mul_r(&ry, &rx);
+        mat4f_mul_r(&rz, &ry);
+
+        Mat4f_t model = rz;
+        angle += 0.05f;
+
+        Vec4f_t projected[8];
+        for(int i=0;i<8;i++) {
+            Vec4f_t v = mat4f_mul_vec4f(model, cubeVertices[i]); // rotation
+            projected[i] = mat4f_mul_vec4f(proj, mat4f_mul_vec4f(view, v)); // model * view * proj
+            
+            normCoord_r(&projected[i]);
+            float depth = (v.z + 1.f) * 0.5f; // zbuffer
+
+            viewport_r(&projected[i], width, height);
+            projected[i].z = depth;
+        }
+    
+        for(int i=0;i<12;i++) {
+            int a = cubeEdges[i][0];
+            int b = cubeEdges[i][1];
+            drawLine(projected[a], projected[b], width, height);
+        }
+        renderCanvas(width, height);
+        sleep_ms(100);
+    }
 
     freeCanvas();
     return 0;