change identation, maybe will change back, add own gl functions loading, and glx example

1 files changed, 53 insertions, 0 deletions

diff --git a/texture.c b/texture.c
new file mode 100644
index 0000000..6b63f5c
--- /dev/null
+++ b/texture.c
@@ -0,0 +1,53 @@
+#include "texture.h"
+
+i32
+load_texture(struct arena *arena, struct texture *texture, const char *filename, i32 gamma)
+{
+    stbi_set_flip_vertically_on_load(1);
+    i32 nchannels;
+    u8 *data = stbi_load(filename, &texture->width, &texture->height, &nchannels, 0);
+    if (!data) {
+        info("failed to load \"%s\"", filename);
+        return 0;
+    }
+    u32 internal_format, data_format;
+    switch (nchannels) {
+    case 1:
+        texture->type = texture_r;
+        internal_format = data_format = gl_red;
+        break;
+    case 3:
+        texture->type = texture_rgb;
+        internal_format = gamma ? gl_srgb : gl_rgb;
+        data_format = gl_rgb;
+        break;
+    case 4:
+        texture->type = texture_rgba;
+        internal_format = gamma ? gl_srgb_alpha : gl_rgba;
+        data_format = gl_rgba;
+        break;
+    default:
+        printf("\"%s\" unsupported texture format %i", filename, nchannels);
+        return 0;
+    }
+    u64 size = texture->type * texture->width * texture->height;
+    texture->data = push_arena(arena, size);
+    memmove(texture->data, data, size);
+    stbi_image_free(data);
+
+    gl_gen_textures(1, &texture->id);
+    gl_bind_texture(gl_texture_2d, texture->id);
+    gl_tex_image_2d(gl_texture_2d, 0, internal_format, texture->width,
+                    texture->height, 0, data_format, gl_unsigned_byte,
+                    texture->data);
+    gl_gen_mipmap(gl_texture_2d);
+    gl_tex_parami(gl_texture_2d, gl_texture_wrap_s, gl_repeat);
+    gl_tex_parami(gl_texture_2d, gl_texture_wrap_t, gl_repeat);
+    gl_tex_parami(gl_texture_2d, gl_texture_min_filter, gl_linear_mipmap_linear);
+    gl_tex_parami(gl_texture_2d, gl_texture_mag_filter, gl_linear);
+    gl_bind_texture(gl_texture_2d, 0);
+
+    info("\"%s\" loaded successfully", filename);
+
+    return texture->id;
+}