finally compiling and running, text still needs rework

src/rendering/twn_gl_15_gpu_texture.c

@@ -1,28 +1,68 @@
-static gpu_texture new_gl_texture(void) {
+#include "twn_gpu_texture_c.h"
+#include "twn_util.h"
+
+
+gpu_texture create_gpu_texture(enum texture_filter filter, bool generate_mipmaps) {
     GLuint texture;
     glGenTextures(1, &texture);
     glBindTexture(GL_TEXTURE_2D, texture);
 
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,     GL_REPEAT);
-    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,     GL_REPEAT);
-    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP,    GL_TRUE);
+    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, (GLboolean)generate_mipmaps);
+
+    if (filter == TEXTURE_FILTER_NEAREAST) {
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    } else if (filter == TEXTURE_FILTER_LINEAR) {
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    }
+
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 
 #if !defined(EMSCRIPTEN)
     glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 #endif
 
     glBindTexture(GL_TEXTURE_2D, 0);
-    return create_gpu_texture(TEXTURE_FILTER_NEAREST, true);
+    return texture;
 }
 
+
+void delete_gpu_texture(gpu_texture texture) {
+    glDeleteTextures(1, &texture);
+}
+
+
+void upload_gpu_texture(gpu_texture texture, void *pixels, int channels, int width, int height) {
+    glBindTexture(GL_TEXTURE_2D, texture);
+
+    int format_internal, format;
+    if (channels == 4) {
+        format_internal = GL_RGBA8;
+        format = GL_RGBA;
+    } else if (channels == 1) {
+        format_internal = GL_ALPHA;
+        format = GL_ALPHA;
+    } else {
+        CRY("upload_gpu_texture", "Unsupported channel count");
+        return;
+    }
+
     glTexImage2D(GL_TEXTURE_2D,
                  0,
-                 GL_RGBA8,
-                 surface->w,
-                 surface->h,
+                 format_internal,
+                 width,
+                 height,
                  0,
-                 GL_RGBA,
+                 format,
                  GL_UNSIGNED_BYTE,
-                 surface->pixels);
+                 pixels);
+
+    glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+
+void bind_gpu_texture(gpu_texture texture) {
+    glBindTexture(GL_TEXTURE_2D, texture);
+}