Plate generation.

src/gen.c

@@ -1,6 +1,9 @@
 #include "include/gen.h"
 #include "include/col.h"
 
+#include <stdlib.h>
+#include <time.h>
+
 Vec2 asth[WORLD_SZ][WORLD_SZ] = {
     {
         (Vec2){.x = 1, .y = 2},
@@ -84,10 +87,45 @@ Vec2 asth[WORLD_SZ][WORLD_SZ] = {
     },
 };
 
-Plate lith[NPLATES] = {
+Plate lith[NPLATES];
-    (Plate){.col = COL_BLU,
+
+// Find the point for an index to the edge of the world.
+Pt world_edge_idx_to_pt(int idx) {
+    if (0 <= idx && idx < 8) {
+        return (Pt){idx, 0};
+    } else if (8 <= idx && idx < 16) {
+        return (Pt){7, idx - 8};
+    } else if (16 <= idx && idx < 24) {
+        return (Pt){idx - 16, 0};
+    } else if (24 <= idx && idx < 32) {
+        return (Pt){7, idx - 24};
+    } else {
+        exit(122);
+    }
+}
+
+void gen_lith() {
+    srand(time(NULL));
+
+    Pt p1 = {(rand() % 6) + 1, 0};
+    Pt p2 = {(rand() % 6) + 1, 7};
+
+    lith[0] = (Plate){
+        .col = COL_RED,
         .nverts = 4,
-            .verts = {(Pt){0, 0}, (Pt){7, 0}, (Pt){7, 5}, (Pt){4, 4}}},
+        .verts = {
-    (Plate){COL_RED, 4, {(Pt){0, 0}, (Pt){4, 4}, (Pt){2, 7}, (Pt){0, 7}}},
+            (Pt){0, 0},
-    (Plate){COL_GRN, 4, {(Pt){4, 4}, (Pt){7, 5}, (Pt){7, 7}, (Pt){2, 7}}},
+            p1,
+            p2,
+            (Pt){0, 7},
+        },
     };
+    lith[1] = (Plate){.col = COL_RED,
+                      .nverts = 4,
+                      .verts = {
+                          p1,
+                          (Pt){7, 0},
+                          (Pt){7, 7},
+                          p2,
+                      }};
+}

src/include/gen.h

@@ -6,7 +6,7 @@
 #include <stdint.h>
 
 #define WORLD_SZ 8
-#define NPLATES 3
+#define NPLATES 2
 
 // A two dimensional vector.
 typedef struct {
@@ -25,7 +25,7 @@ typedef struct {
 typedef struct {
     Col col;        // The color the plate should be drawn as.
     uint8_t nverts; // The number of vertices the plate has.
-    Pt verts[4];    // The vertices of the plate.
+    Pt verts[10];    // The vertices of the plate.
 } Plate;
 
 // The asthenosphere; contains a grid of force vectors.
@@ -33,6 +33,6 @@ extern Vec2 asth[WORLD_SZ][WORLD_SZ];
 // The lithosphere; contians a list of plates.
 extern Plate lith[NPLATES];
 
-void gen(void);
+void gen_lith(void);
 
 #endif

src/main.c

@@ -1,10 +1,12 @@
 #include "include/main.h"
 
+#include "include/gen.h"
 #include "include/render.h"
 
 #include <raylib.h>
 
 int main(int argc, char** argv) {
+    gen_lith();
     InitWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "Terrin");
     SetTargetFPS(110);
 

src/render.c

@@ -21,7 +21,7 @@ void render() {
 
         // Convert the vertices from world coordinates (Pt) to screen
         // coordinates (Vector2).
-        Vector2 screen_verts[4];
+        Vector2 screen_verts[10];
         for (int j = 0; j < plate.nverts; j++) {
             screen_verts[j] = PointToVector2(plate.verts[j]);
         }