move pipelines and texture modes to deferred commands

src/rendering/twn_gl_15_rendering.c

@@ -118,7 +118,6 @@ typedef struct {
 
     bool textured, texture_repeat;
     TextureKey texture;
-    TextureMode texture_mode;
 
     GLuint element_buffer;
     GLsizei element_count;
@@ -134,19 +133,6 @@ typedef struct {
 } DeferredCommandClear;
 
 
-typedef struct {
-    enum DeferredCommandType {
-        DEFERRED_COMMAND_TYPE_DRAW_ELEMENTS,
-        DEFERRED_COMMAND_TYPE_CLEAR,
-    } type;
-
-    union {
-        DeferredCommandDrawElements draw_elements;
-        DeferredCommandClear clear;
-    };
-} DeferredCommand;
-
-
 typedef enum {
     PIPELINE_NO,
     PIPELINE_SPACE,
@@ -154,6 +140,33 @@ typedef enum {
 } Pipeline;
 
 
+typedef struct {
+    Pipeline pipeline;
+} DeferredCommandUsePipeline;
+
+
+typedef struct {
+    TextureMode mode;
+} DeferredCommandUseTextureMode;
+
+
+typedef struct {
+    enum DeferredCommandType {
+        DEFERRED_COMMAND_TYPE_DRAW_ELEMENTS,
+        DEFERRED_COMMAND_TYPE_CLEAR,
+        DEFERRED_COMMAND_TYPE_USE_PIPIELINE,
+        DEFERRED_COMMAND_TYPE_USE_TEXTURE_MODE,
+    } type;
+
+    union {
+        DeferredCommandDrawElements draw_elements;
+        DeferredCommandClear clear;
+        DeferredCommandUsePipeline use_pipeline;
+        DeferredCommandUseTextureMode use_texture_mode;
+    };
+} DeferredCommand;
+
+
 static Pipeline pipeline_last_used = PIPELINE_NO;
 
 
@@ -165,13 +178,15 @@ static Pipeline pipeline_last_used = PIPELINE_NO;
 static size_t scratch_va_front_used, scratch_va_back_used;
 static GLuint *front_scratch_vertex_arrays, *back_scratch_vertex_arrays;
 static GLuint **current_scratch_vertex_array = &front_scratch_vertex_arrays;
+
 static void restart_scratch_vertex_arrays(void) {
     scratch_va_front_used = 0;
     scratch_va_back_used = 0;
 
-    if (ctx.render_double_buffered)
+    if (ctx.render_double_buffered) {
         current_scratch_vertex_array = current_scratch_vertex_array == &front_scratch_vertex_arrays ?
                 &back_scratch_vertex_arrays : &front_scratch_vertex_arrays;
+    }
 }
 
 
@@ -186,14 +201,17 @@ GLuint get_scratch_vertex_array(void) {
     }
 
     (*used)++;
-    return (*current_scratch_vertex_array)[arrlenu(*current_scratch_vertex_array) - 1];
+    return (*current_scratch_vertex_array)[*used - 1];
 }
 
 
-static DeferredCommand *deferred_commands;
+static void finally_use_2d_pipeline(void);
-static void issue_deferred_draw_commands(void) {
+static void finally_use_space_pipeline(void);
-    use_2d_pipeline();
+static void finally_use_texture_mode(TextureMode mode);
 
+static DeferredCommand *deferred_commands;
+
+static void issue_deferred_draw_commands(void) {
     for (size_t i = 0; i < arrlenu(deferred_commands); ++i) {
         switch (deferred_commands[i].type) {
             case DEFERRED_COMMAND_TYPE_CLEAR: {
@@ -230,8 +248,6 @@ static void issue_deferred_draw_commands(void) {
                                 command.vertices.stride,
                                 (void *)command.vertices.offset);
 
-                use_texture_mode(command.texture_mode);
-
                 if (command.texcoords.arity != 0) {
                     SDL_assert(command.texcoords.buffer == command.vertices.buffer);
 
@@ -293,6 +309,27 @@ static void issue_deferred_draw_commands(void) {
                 break;
             }
 
+            case DEFERRED_COMMAND_TYPE_USE_PIPIELINE: {
+                switch (deferred_commands[i].use_pipeline.pipeline) {
+                    case PIPELINE_2D:
+                        finally_use_2d_pipeline();
+                        break;
+                    case PIPELINE_SPACE:
+                        finally_use_space_pipeline();
+                        break;
+                    case PIPELINE_NO:
+                    default:
+                        SDL_assert(false);
+                }
+
+                break;
+            }
+
+            case DEFERRED_COMMAND_TYPE_USE_TEXTURE_MODE: {
+                finally_use_texture_mode(deferred_commands[i].use_texture_mode.mode);
+                break;
+            }
+
             default:
                 SDL_assert(false);
         }
@@ -318,7 +355,6 @@ void clear_draw_buffer(void) {
 
 
 void start_render_frame(void) {
-    restart_scratch_vertex_arrays();
     clear_draw_buffer();
 }
 
@@ -328,12 +364,14 @@ void end_render_frame(void) {
         issue_deferred_draw_commands();
         SDL_GL_SwapWindow(ctx.window);
         arrsetlen(deferred_commands, 0);
+        restart_scratch_vertex_arrays();
     } else {
         /* instead of waiting for frame to finish for the swap, we continue */
         /* while issuing new state for the next call, but deferring any fragment emitting calls for later  */
         /* actual swap will happen when next frame is fully finished, introducing a delay */
         SDL_GL_SwapWindow(ctx.window);
         issue_deferred_draw_commands();
+        restart_scratch_vertex_arrays();
         glFlush();
         arrsetlen(deferred_commands, 0);
     }
@@ -341,6 +379,16 @@ void end_render_frame(void) {
 
 
 void use_space_pipeline(void) {
+    DeferredCommand const command = {
+        .type = DEFERRED_COMMAND_TYPE_USE_PIPIELINE,
+        .use_pipeline = { PIPELINE_SPACE }
+    };
+
+    arrpush(deferred_commands, command);
+}
+
+
+static void finally_use_space_pipeline(void) {
     if (pipeline_last_used == PIPELINE_SPACE)
         return;
 
@@ -378,6 +426,16 @@ void use_space_pipeline(void) {
 
 
 void use_2d_pipeline(void) {
+    DeferredCommand const command = {
+        .type = DEFERRED_COMMAND_TYPE_USE_PIPIELINE,
+        .use_pipeline = { PIPELINE_2D }
+    };
+
+    arrpush(deferred_commands, command);
+}
+
+
+static void finally_use_2d_pipeline(void) {
     if (pipeline_last_used == PIPELINE_SPACE) {
         glClear(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
         glFlush();
@@ -453,6 +511,16 @@ void render_circle(const CirclePrimitive *circle) {
 
 
 void use_texture_mode(TextureMode mode) {
+    DeferredCommand const command = {
+        .type = DEFERRED_COMMAND_TYPE_USE_TEXTURE_MODE,
+        .use_texture_mode = { mode }
+    };
+
+    arrpush(deferred_commands, command);
+}
+
+
+static void finally_use_texture_mode(TextureMode mode) {
     static GLuint lists = 0;
     if (!lists) {
         lists = glGenLists(3);
@@ -596,7 +664,7 @@ void finally_render_quads(const Primitive2D primitives[],
     command.element_count = 6 * (GLsizei)batch.size;
     command.range_end = 6 * (GLsizei)batch.size;
 
-    command.texture_mode = batch.mode;
+    use_texture_mode(batch.mode);
 
     DeferredCommand final_command = {
         .type = DEFERRED_COMMAND_TYPE_DRAW_ELEMENTS,