From 51d85c011b718af9fb465e650a94a866769443a2 Mon Sep 17 00:00:00 2001
From: cat <cat@no.thanks>
Date: Sun, 25 May 2025 14:40:05 +1000
Subject: [PATCH] image display test

bring your own test.png
---
 dat.h     | 11 ++++++++++
 slutpet.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/dat.h b/dat.h
index 09895e0..0a724de 100644
--- a/dat.h
+++ b/dat.h
@@ -1,5 +1,16 @@
+typedef struct Image Image;
+struct Image {
+	int w;
+	int h;
+	int bpp;
+	unsigned char *data;
+	SDL_Texture *tex;
+};
+
 typedef struct State State;
 struct State {
 	SDL_Window *win;
 	SDL_Renderer *ren;
+
+	Image *test;
 };
diff --git a/slutpet.c b/slutpet.c
index 01b4d33..3e4f934 100644
--- a/slutpet.c
+++ b/slutpet.c
@@ -9,6 +9,26 @@
 void
 SDL_AppQuit(void *as, SDL_AppResult res)
 {
+	State *st;
+
+	st = as;
+	if (st) {
+		if (st->test) {
+			if (st->test->tex) {
+				SDL_Log("free test texture...");
+				SDL_DestroyTexture(st->test->tex);
+			}
+			if (st->test->data) {
+				SDL_Log("free test img data...");
+				SDL_free(st->test->data);
+			}
+			SDL_Log("free test img...");
+			SDL_free(st->test);
+		}
+	        SDL_Log("free state...");
+	        SDL_free(st);
+	}
+
 	SDL_Log("bye!");
 	return;
 }
@@ -29,6 +49,13 @@ SDL_AppEvent(void *as, SDL_Event *ev)
 SDL_AppResult
 SDL_AppIterate(void *as)
 {
+	State *st = as;
+
+	SDL_SetRenderDrawColor(st->ren, 0, 0, 0, SDL_ALPHA_TRANSPARENT);
+	SDL_RenderClear(st->ren);
+
+	SDL_RenderTexture(st->ren, st->test->tex, NULL, NULL);
+	SDL_RenderPresent(st->ren);
 	return SDL_APP_CONTINUE;
 }
 
@@ -36,6 +63,7 @@ SDL_AppResult
 SDL_AppInit(void **as, int argc, char **argv)
 {
 	State *st;
+	SDL_Surface *sur;
 
 	SDL_Log("init sdl...");
 	if (!SDL_Init(SDL_INIT_VIDEO)) {
@@ -62,6 +90,39 @@ SDL_AppInit(void **as, int argc, char **argv)
 		return SDL_APP_FAILURE;
 	}
 
+	SDL_Log("create test image...");
+	st->test = SDL_calloc(1, sizeof(Image));
+	if (!st->test) {
+		SDL_LogCritical(SDL_LOG_CATEGORY_APPLICATION,
+				"mem alloc fail: %s", SDL_GetError());
+		return SDL_APP_FAILURE;
+	}
+
+	st->test->data = stbi_load("test.png", &st->test->w, &st->test->h,
+			&st->test->bpp, 4);
+	if (!st->test->data) {
+		SDL_LogCritical(SDL_LOG_CATEGORY_APPLICATION,
+				"mem alloc fail: %s", SDL_GetError());
+		return SDL_APP_FAILURE;
+	}
+
+	sur = SDL_CreateSurfaceFrom(st->test->w, st->test->h,
+			SDL_PIXELFORMAT_RGBA32, st->test->data,
+			st->test->w * 4);
+	if (!sur) {
+		SDL_LogCritical(SDL_LOG_CATEGORY_APPLICATION,
+				"surface creation fail: %s", SDL_GetError());
+		return SDL_APP_FAILURE;
+	}
+
+	st->test->tex = SDL_CreateTextureFromSurface(st->ren, sur);
+	if (!st->test->tex) {
+		SDL_LogCritical(SDL_LOG_CATEGORY_APPLICATION,
+				"surface creation fail: %s", SDL_GetError());
+		SDL_DestroySurface(sur);
+		return SDL_APP_FAILURE;
+	}
+
 	SDL_Log("it work");
 	return SDL_APP_CONTINUE;
 }