Implement diffuse texture loading and basic material support

1 files changed, 36 insertions, 0 deletions

diff --git a/tex.c b/tex.c
new file mode 100644
index 0000000..6f27b8a
--- /dev/null
+++ b/tex.c
@@ -0,0 +1,36 @@
+#include <assert.h>
+#include <png.h>
+#include <stdlib.h>
+
+#include "eprintf.h"
+#include "tex.h"
+
+GLuint png2tex(FILE *f)
+{
+	png_image pi = { .version = PNG_IMAGE_VERSION };
+	unsigned char *data;
+	size_t size;
+	GLuint id;
+
+	assert(f != NULL);
+
+	png_image_begin_read_from_stdio(&pi, f);
+	pi.format = PNG_FORMAT_RGB;
+	size = sizeof *data * 3 * pi.width * pi.height;
+	data = emalloc(size);
+	png_image_finish_read(&pi, NULL, data, size / pi.height, NULL);
+
+	gl_tex_gen(1, &id);
+	gl_tex_bind(GL_TEXTURE_2D, id);
+	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+	gl_tex_parami(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+	gl_tex_img2d(GL_TEXTURE_2D, 0, GL_RGB, pi.width, pi.height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
+	gl_tex_genmip(GL_TEXTURE_2D);
+
+	free(data);
+	png_image_free(&pi);
+
+	return id;
+}