add teapot example

1 files changed, 73 insertions, 0 deletions

diff --git a/examples/teapot.c b/examples/teapot.c
new file mode 100644
index 0000000..889b6de
--- /dev/null
+++ b/examples/teapot.c
@@ -0,0 +1,73 @@
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+
+#include "../sponge.h"
+#define SPONGE_EXAMPLE_IMPLEMENTATION
+#define SPONGE_EXAMPLE_INIT_DEFINED
+#define SPONGE_EXAMPLE_MOUSE_MOVE_DEFINED
+#define SPONGE_EXAMPLE_DRAW_FRAME_3D_DEFINED
+#include "../example.h"
+
+#define FOV (60.0f / PI * 2.0f)
+#define DISTANCE (10.0f)
+
+static int32_t mouse_x;
+static int32_t mouse_y;
+
+static sponge_Vec3 *positions;
+static sponge_Color32 *colors;
+static int32_t *triangles;
+static size_t triangles_count;
+
+// TODO(kard): make proper error checking
+void init() {
+    FILE *handle = fopen("./examples/teapot.txt", "r");
+    assert(handle);
+    fscanf(handle, "%zu", &triangles_count);
+    triangles_count *= 3;
+    positions = malloc(triangles_count * sizeof(sponge_Vec3));
+    colors    = malloc(triangles_count * sizeof(sponge_Color32));
+    triangles = malloc(triangles_count * sizeof(int32_t));
+    assert(positions && colors && triangles);
+
+    for (size_t i = 0; i < triangles_count; i++) {
+        fscanf(handle, "%f %f %f", &positions[i].x, &positions[i].y, &positions[i].z);
+        sponge_Vec3 normal;
+        fscanf(handle, "%f %f %f", &normal.x, &normal.y, &normal.z);
+        sponge_ColorF color;
+        color.a = 255.0f;
+        color.r = (normal.x + 1.0f) * (255.0f * 0.5f);
+        color.g = (normal.y + 1.0f) * (255.0f * 0.5f);
+        color.b = (normal.z + 1.0f) * (255.0f * 0.5f);
+        colors[i] = sponge_colorf_to_color32(color);
+
+        // invert winding
+        int32_t t = (i / 3) * 3;
+        triangles[i] = t + (2 - (i % 3));
+    }
+
+    fclose(handle);
+}
+
+void mouse_move(int32_t x, int32_t y) {
+    mouse_x = x;
+    mouse_y = y;
+}
+
+void draw_frame_3d(sponge_Texture c, float *depths) {
+    sponge_clear_3d(c, depths, sponge_color32_make(0xFF000000));
+
+    sponge_Mat4 model = sponge_mat4_identity();
+    model = sponge_mat4_mul_mat4(model, sponge_mat4_translate(0.0f, -2.0f, 0.0f));
+
+    float rot_y = (float)mouse_x / (float)c.width * PI * 2.0f;
+    float rot_x = ((float)mouse_y / (float)c.height * PI) - (PI * 0.5f);
+    sponge_Mat4 view = sponge_mat4_identity();
+    view = sponge_mat4_mul_mat4(view, sponge_mat4_rotate(rot_x, rot_y, 0.0f));
+    view = sponge_mat4_mul_mat4(view, sponge_mat4_translate(0.0f, 0.0f, -10.0f));
+
+
+    sponge_Mat4 proj = sponge_mat4_projection(FOV, (float)c.width / (float)c.height, 1.0f, 100.0f);
+    sponge_draw_mesh_col(c, depths, model, view, proj, positions, colors, triangles, triangles_count);
+}