twn_gl_15_rendering.c: use display lists to cache common series of calls

src/rendering/twn_gl_15_rendering.c

@@ -59,18 +59,17 @@ static Pipeline pipeline_last_used = PIPELINE_NO;
 
 
 void use_space_pipeline(void) {
+    static GLuint list = 0;
+    if (!list) {
+        list = glGenLists(1);
+
+        glNewList(list, GL_COMPILE); {
             glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
             glShadeModel(GL_SMOOTH);
 
             if (GLAD_GL_ARB_depth_clamp)
                 glDisable(GL_DEPTH_CLAMP);
 
-    glMatrixMode(GL_PROJECTION);
-    glLoadMatrixf(&camera_projection_matrix.row[0].x);
-
-    glMatrixMode(GL_MODELVIEW);
-    glLoadMatrixf(&camera_look_at_matrix.row[0].x);
-
             glEnable(GL_CULL_FACE);
             glEnable(GL_DEPTH_TEST);
             glDepthMask(GL_TRUE);
@@ -84,6 +83,16 @@ void use_space_pipeline(void) {
 
             /* solid white, no modulation */
             glColor4ub(255, 255, 255, 255);
+        } glEndList();
+    }
+
+    glCallList(list);
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadMatrixf(&camera_projection_matrix.row[0].x);
+
+    glMatrixMode(GL_MODELVIEW);
+    glLoadMatrixf(&camera_look_at_matrix.row[0].x);
 
     pipeline_last_used = PIPELINE_SPACE;
 }
@@ -95,6 +104,11 @@ void use_2d_pipeline(void) {
         glFlush();
     }
 
+    static GLuint list = 0;
+    if (!list) {
+        list = glGenLists(1);
+
+        glNewList(list, GL_COMPILE); {
             glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
             glShadeModel(GL_FLAT);
 
@@ -102,6 +116,15 @@ void use_2d_pipeline(void) {
             if (GLAD_GL_ARB_depth_clamp)
                 glDisable(GL_DEPTH_CLAMP);
 
+            glEnable(GL_TEXTURE_2D);
+            glActiveTexture(GL_TEXTURE0);
+            glDisable(GL_CULL_FACE);
+            glEnable(GL_DEPTH_TEST);
+        } glEndList();
+    }
+
+    glCallList(list);
+
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     glOrtho(0, (double)ctx.base_render_width, (double)ctx.base_render_height, 0, -1, 1);
@@ -109,11 +132,6 @@ void use_2d_pipeline(void) {
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
 
-    glEnable(GL_TEXTURE_2D);
-    glActiveTexture(GL_TEXTURE0);
-    glDisable(GL_CULL_FACE);
-    glEnable(GL_DEPTH_TEST);
-
     pipeline_last_used = PIPELINE_2D;
 }
 
@@ -183,23 +201,40 @@ void render_circle(const CirclePrimitive *circle) {
 
 
 void use_texture_mode(TextureMode mode) {
-    if (mode == TEXTURE_MODE_GHOSTLY) {
+    GLuint lists = 0;
+    if (!lists) {
+        lists = glGenLists(3);
+
+        glNewList(lists + 0, GL_COMPILE); {
             glEnable(GL_BLEND);
             glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
             glDepthFunc(GL_ALWAYS);
             glDepthMask(GL_FALSE);
             glDisable(GL_ALPHA_TEST);
-    } else if (mode == TEXTURE_MODE_SEETHROUGH) {
+        } glEndList();
+
+        glNewList(lists + 1, GL_COMPILE); {
             glDisable(GL_BLEND);
             glDepthFunc(GL_LEQUAL);
             glDepthMask(GL_TRUE);
             glEnable(GL_ALPHA_TEST);
             glAlphaFunc(GL_EQUAL, 1.0f);
-    } else {
+        } glEndList();
+
+        glNewList(lists + 2, GL_COMPILE); {
             glDisable(GL_BLEND);
             glDepthFunc(GL_LESS);
             glDepthMask(GL_TRUE);
             glDisable(GL_ALPHA_TEST);
+        } glEndList();
+    }
+
+    if (mode == TEXTURE_MODE_GHOSTLY) {
+        glCallList(lists + 0);
+    } else if (mode == TEXTURE_MODE_SEETHROUGH) {
+        glCallList(lists + 1);
+    } else {
+        glCallList(lists + 2);
     }
 }
 
@@ -517,10 +552,6 @@ void finally_render_skybox(char *paths) {
     glEnable(GL_TEXTURE_CUBE_MAP);
     glBindTexture(GL_TEXTURE_CUBE_MAP, cubemap);
 
-    /* note: assumes that space pipeline is applied already */
-    glDisable(GL_ALPHA_TEST);
-    glDepthMask(GL_TRUE);
-
     if (loading_needed) {
         /* load all the sides */
         char *expanded = expand_asterisk(paths, "up");
@@ -548,8 +579,17 @@ void finally_render_skybox(char *paths) {
         SDL_free(expanded);
     }
 
-    /* TODO: use lists at the very least */
     /* TODO: figure out which coordinates to use to not have issues with far z */
+    /* TODO: recalculate the list if far z requirement changes */
+
+    static GLuint list = 0;
+    if (!list) {
+        list = glGenLists(1);
+
+        glNewList(list, GL_COMPILE); {
+            /* note: assumes that space pipeline is applied already */
+            glDisable(GL_ALPHA_TEST);
+            glDepthMask(GL_TRUE);
 
             glBegin(GL_QUADS); {
                 /* up */
@@ -614,4 +654,9 @@ void finally_render_skybox(char *paths) {
             } glEnd();
 
             glDisable(GL_TEXTURE_CUBE_MAP);
+
+        } glEndList();
+    }
+
+    glCallList(list);
 }