textures working on web, separation of vertex and index buffers (actually matters)

src/rendering/twn_gl_15_rendering.c

@@ -50,8 +50,9 @@ bool render_init(void) {
 
     log_info("OpenGL context: %s\n", glGetString(GL_VERSION));
 
-#ifndef __EMSCRIPTEN__
     glHint(GL_TEXTURE_COMPRESSION_HINT, GL_NICEST);
+
+#ifndef __EMSCRIPTEN__
     glHint(GL_GENERATE_MIPMAP_HINT, GL_NICEST);
     glHint(GL_FOG_HINT, GL_FASTEST);
 
@@ -196,59 +197,79 @@ static void finally_use_2d_pipeline(void) {
     pipeline_last_used = PIPELINE_2D;
 }
 
+
+static void setup_ghostly_texture_mode(void) {
+#ifndef __EMSCRIPTEN__
+    static GLuint list = 0;
+    if (!list) {
+        list = glGenLists(1);
+        glNewList(list, GL_COMPILE);
+#endif
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        glDepthFunc(GL_LESS);
+        glDepthMask(GL_FALSE);
+        glDisable(GL_ALPHA_TEST);
+#ifndef __EMSCRIPTEN__
+        glEndList();
+    }
+    glCallList(list);
+#endif
+}
+
+
+static void setup_seethrough_texture_mode(void) {
+#ifndef __EMSCRIPTEN__
+    static GLuint list = 0;
+    if (!list) {
+        list = glGenLists(1);
+        glNewList(list, GL_COMPILE);
+#endif
+        glDisable(GL_BLEND);
+        glDepthFunc(GL_LESS);
+        glDepthMask(GL_TRUE);
+        glEnable(GL_ALPHA_TEST);
+        glAlphaFunc(GL_EQUAL, 1.0f);
+#ifndef __EMSCRIPTEN__
+        glEndList();
+    }
+    glCallList(list);
+#endif
+}
+
+
+static void setup_opaque_texture_mode(void) {
+#ifndef __EMSCRIPTEN__
+    static GLuint list = 0;
+    if (!list) {
+        list = glGenLists(1);
+        glNewList(list, GL_COMPILE);
+#endif
+        glDisable(GL_BLEND);
+        glDepthFunc(GL_LESS);
+        glDepthMask(GL_TRUE);
+        glDisable(GL_ALPHA_TEST);
+#ifndef __EMSCRIPTEN__
+        glEndList();
+    }
+    glCallList(list);
+#endif
+}
+
+
 /* TODO: ensure we minimize depth func switching to enable Hi-Z (hierarchical depth) optimizations */
 static void finally_use_texture_mode(TextureMode mode) {
     if (texture_mode_last_used == mode)
         return;
 
-#ifndef __EMSCRIPTEN__
-    static GLuint lists = 0;
-    if (!lists) {
-        lists = glGenLists(3);
-
-        /* ghostly */
-        glNewList(lists + 0, GL_COMPILE); {
-#endif
-            glEnable(GL_BLEND);
-            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-            glDepthFunc(GL_LESS);
-            glDepthMask(GL_FALSE);
-            glDisable(GL_ALPHA_TEST);
-#ifndef __EMSCRIPTEN__
-        } glEndList();
-
-        /* seethrough */
-        glNewList(lists + 1, GL_COMPILE); {
-#endif
-            glDisable(GL_BLEND);
-            glDepthFunc(GL_LESS);
-            glDepthMask(GL_TRUE);
-            glEnable(GL_ALPHA_TEST);
-            glAlphaFunc(GL_EQUAL, 1.0f);
-#ifndef __EMSCRIPTEN__
-        } glEndList();
-
-        /* opaque */
-        glNewList(lists + 2, GL_COMPILE); {
-#endif
-            glDisable(GL_BLEND);
-            glDepthFunc(GL_LESS);
-            glDepthMask(GL_TRUE);
-            glDisable(GL_ALPHA_TEST);
-#ifndef __EMSCRIPTEN__
-        } glEndList();
-    }
-
     if (mode == TEXTURE_MODE_GHOSTLY) {
-        glCallList(lists + 0);
+        setup_ghostly_texture_mode();
     } else if (mode == TEXTURE_MODE_SEETHROUGH) {
-        glCallList(lists + 1);
+        setup_seethrough_texture_mode();
     } else {
-        glCallList(lists + 2);
+        setup_opaque_texture_mode();
     }
 
-#endif
-
     texture_mode_last_used = mode;
 }
 
@@ -287,6 +308,40 @@ void finish_vertex_builder(VertexBufferBuilder *builder) {
 }
 
 
+IndexBufferBuilder build_index_buffer(IndexBuffer buffer, size_t bytes) {
+    SDL_assert(bytes != 0);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, bytes, NULL, GL_STREAM_DRAW);
+#ifndef __EMSCRIPTEN__
+    void *mapping = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY);
+#else
+    void *mapping = SDL_malloc(bytes);
+#endif
+    if (!mapping)
+        CRY("build_vertex_buffer", "Error mapping a vertex array buffer");
+
+    return (IndexBufferBuilder) {
+        .base = mapping,
+        .size = bytes,
+    };
+}
+
+
+void finish_index_builder(IndexBufferBuilder *builder) {
+#ifndef __EMSCRIPTEN__
+    if (!glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER))
+        CRY("finish_vertex_builder", "Error unmapping a vertex array buffer");
+#else
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, builder->size, builder->base, GL_STREAM_DRAW);
+    SDL_free(builder->base);
+#endif
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+    builder->base = 0;
+    builder->size = 0;
+}
+
+
 static void load_cubemap_side(const char *path, GLenum target) {
     SDL_Surface *surface = textures_load_surface(path);
     /* TODO: sanity check whether all of them have same dimensions? */