Start abstracting the rendering backend away to make it easier to switch to GPU rendering later

2026-05-24 21:59:29 -04:00
parent 8f613397d6
commit 6314ad7f26
13 changed files with 159 additions and 82 deletions
--- a/src/renderer.c
+++ b/src/renderer.c
@@ -0,0 +1,100 @@
+#include <SDL3/SDL.h>
+
+#include <akgl/renderer.h>
+#include <akgl/staticstring.h>
+#include <akgl/registry.h>
+#include <akgl/heap.h>
+#include <akgl/game.h>
+
+#include <akerror.h>
+#include <akstdlib.h>
+
+akerr_ErrorContext AKERR_NOIGNORE *akgl_render_init2d(akgl_RenderBackend *self)
+{
+    akgl_String *width = NULL;
+    akgl_String *height = NULL;
+    int screenwidth;
+    int screenheight;
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, self, AKERR_NULLPOINTER, "self");
+
+    PASS(e, akgl_get_property("game.screenwidth", &width, "0"));
+    PASS(e, akgl_get_property("game.screenheight", &height, "0"));
+    PASS(e, aksl_atoi(width->data, &screenwidth));
+    PASS(e, aksl_atoi(height->data, &screenheight));
+    SDL_Log("Initializing screen (%sx%s = %dx%d)", width->data, height->data, screenwidth, screenheight);
+    PASS(e, akgl_heap_release_string(width));
+    PASS(e, akgl_heap_release_string(height));
+    
+    FAIL_ZERO_RETURN(
+	e,
+	SDL_CreateWindowAndRenderer(game.uri, screenwidth, screenheight, 0, &window, &self->sdl_renderer),
+	AKGL_ERR_SDL,
+	"Couldn't create window/renderer: %s",
+	SDL_GetError());
+    
+    camera.x = 0;
+    camera.y = 0;
+    camera.w = screenwidth;
+    camera.h = screenheight;
+
+    self->shutdown = &akgl_render_2d_shutdown;
+    self->frame_start = &akgl_render_2d_frame_start;
+    self->frame_end = &akgl_render_2d_frame_end;
+    self->draw_texture = &akgl_render_2d_draw_texture;
+    self->draw_mesh = &akgl_render_2d_draw_mesh;
+    SUCCEED_RETURN(e);
+}
+
+
+akerr_ErrorContext AKERR_NOIGNORE *akgl_render_2d_shutdown(akgl_RenderBackend *self)
+{
+    PREPARE_ERROR(e);
+    SUCCEED_RETURN(e);
+}
+
+akerr_ErrorContext AKERR_NOIGNORE *akgl_render_2d_frame_start(akgl_RenderBackend *self)
+{
+    PREPARE_ERROR(e);
+    SUCCEED_RETURN(e);
+}
+
+akerr_ErrorContext AKERR_NOIGNORE *akgl_render_2d_frame_end(akgl_RenderBackend *self)
+{
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, renderer.sdl_renderer, AKERR_NULLPOINTER, "No valid SDL rendering backend");
+    SDL_RenderPresent(renderer.sdl_renderer);
+    SUCCEED_RETURN(e);
+}
+
+akerr_ErrorContext AKERR_NOIGNORE *akgl_render_2d_draw_texture(akgl_RenderBackend *self, SDL_Texture *texture, SDL_FRect *src, SDL_FRect *dest, double angle, SDL_FPoint *center, SDL_FlipMode flip)
+{
+    PREPARE_ERROR(e);
+    FAIL_ZERO_RETURN(e, self, AKERR_NULLPOINTER, "self");
+    FAIL_ZERO_RETURN(e, texture, AKERR_NULLPOINTER, "texture");
+    //FAIL_ZERO_RETURN(e, src, AKERR_NULLPOINTER, "src");
+    //FAIL_ZERO_RETURN(e, dest, AKERR_NULLPOINTER, "dest");
+
+    if ( angle != 0 ) {
+	FAIL_ZERO_RETURN(e, center, AKERR_NULLPOINTER, "center");
+	FAIL_ZERO_RETURN(
+	    e,
+	    SDL_RenderTextureRotated(self->sdl_renderer, texture, src, dest, angle, center, flip),
+	    AKERR_NULLPOINTER, "%s", SDL_GetError()
+	    );
+    } else {
+	FAIL_ZERO_RETURN(
+	    e,
+	    SDL_RenderTexture(self->sdl_renderer, texture, src, dest),
+	    AKERR_NULLPOINTER, "%s", SDL_GetError()
+	    );
+    }
+    SUCCEED_RETURN(e);
+}
+
+akerr_ErrorContext AKERR_NOIGNORE *akgl_render_2d_draw_mesh(akgl_RenderBackend *self)
+{
+    PREPARE_ERROR(e);
+    FAIL_RETURN(e, AKERR_API, "Not implemented");
+}
+