From 0a40f97a1eb0de80e38a51d19d6b7c92d766554b Mon Sep 17 00:00:00 2001
From: kdx <kikoodx@paranoici.org>
Date: Fri, 14 Apr 2023 01:42:21 +0200
Subject: render to screen

---
 README.md              |  4 +---
 build.sh               |  8 +++++---
 samples/input.orgaasm  |  4 ----
 samples/screen.orgaasm |  8 ++++++++
 src/orgaemu.c          | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 70 insertions(+), 10 deletions(-)
 delete mode 100644 samples/input.orgaasm
 create mode 100644 samples/screen.orgaasm

diff --git a/README.md b/README.md
index 1ee758b..a887cc1 100644
--- a/README.md
+++ b/README.md
@@ -7,9 +7,7 @@
 
 input data is a single short at __0xbffe__
 
-screen data is 8-bit indexed on two layers
-(one short is two pixels, one for each layer), and located
-__from 0xbfff to 0xffff__
+screen data is r5g6b5 __from 0xbfff to 0xffff__
 
 # OPS
 
diff --git a/build.sh b/build.sh
index c8b9b9f..85d04c6 100755
--- a/build.sh
+++ b/build.sh
@@ -1,4 +1,6 @@
 #!/bin/sh
-CFLAGS='-std=c99 -Wall -Wextra'
-tcc $CFLAGS -o orgaasm src/orgaasm.c
-tcc $CFLAGS -o orgaemu src/orgaemu.c
+CFLAGS='-std=c99 -Wall -Wextra -O2'
+printf 'orgaasm\n'
+gcc $CFLAGS -o orgaasm src/orgaasm.c
+printf 'orgaemu\n'
+gcc $CFLAGS -o orgaemu src/orgaemu.c -lSDL2
diff --git a/samples/input.orgaasm b/samples/input.orgaasm
deleted file mode 100644
index a97f70c..0000000
--- a/samples/input.orgaasm
+++ /dev/null
@@ -1,4 +0,0 @@
-  SLP
-@loop
-  LIT ,Input LDA DBG POP
-  JMP ,loop
diff --git a/samples/screen.orgaasm b/samples/screen.orgaasm
new file mode 100644
index 0000000..7b16d71
--- /dev/null
+++ b/samples/screen.orgaasm
@@ -0,0 +1,8 @@
+	LIT ,Screen
+@loop
+	DUP DUP STA   ( draw pixel )
+	INC DUP       ( overflow check )
+	JNZ ,loop
+@infinite
+	SLP
+	JMP ,infinite
diff --git a/src/orgaemu.c b/src/orgaemu.c
index b3c712d..4b7630e 100644
--- a/src/orgaemu.c
+++ b/src/orgaemu.c
@@ -2,15 +2,23 @@
 #include "ops.h"
 #include <stdio.h>
 #include <stdint.h>
+#include <SDL2/SDL.h>
 
 #define MEM_SIZE 0xffff
 
 static uint16_t *mem = NULL, *stack = NULL, *rstack = NULL;
 static size_t stack_ptr = 0, rstack_ptr = 0;
+static SDL_Window *window = NULL;
+static SDL_Renderer *renderer = NULL;
 
 static int
 fail(void)
 {
+	if (renderer != NULL)
+		SDL_DestroyRenderer(renderer);
+	if (window != NULL)
+		SDL_DestroyWindow(window);
+	SDL_Quit();
 	if (mem != NULL)
 		free(mem);
 	if (stack != NULL)
@@ -26,6 +34,42 @@ get_short(const unsigned char *s)
 	return s[0] | (s[1] * 0x0100);
 }
 
+static int
+cycle_events(void)
+{
+	SDL_Event e;
+	while (SDL_PollEvent(&e)) {
+		switch (e.type) {
+		case SDL_QUIT:
+			return 1;
+		default:
+			break;
+		}
+	}
+	return 0;
+}
+
+static void
+render(uint16_t *mem)
+{
+	SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+	SDL_RenderClear(renderer);
+	for (int y = 0; y < 128; y++) {
+		for (int x = 0; x < 128; x++) {
+			const uint16_t pixel = mem[x + y * 128];
+			if (!pixel)
+				continue;
+			const uint16_t r = (pixel & 0x1f) << 3;
+			const uint16_t g = ((pixel >> 5) & 0x3f) << 2;
+			const uint16_t b = ((pixel >> 11) & 0x1f) << 3;
+			SDL_SetRenderDrawColor(renderer, r, g, b, 255);
+			SDL_RenderDrawPoint(renderer, x, y);
+		}
+	}
+	SDL_RenderPresent(renderer);
+	SDL_Delay(1000 / 30);
+}
+
 static void
 push(uint16_t v)
 {
@@ -207,6 +251,9 @@ exec_op(uint16_t *mem, long pc)
 		return pc + 1;
 	}
 	case OP_SLP:
+		if (cycle_events())
+			return MEM_SIZE;
+		render(mem + 0xbfff);
 		return pc + 1;
 	case OP_INC:
 		push(pop() + 1);
@@ -280,6 +327,15 @@ main(int argc, char **argv)
 		return fail();
 	}
 
+	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+		fprintf(stderr, "%s\n", SDL_GetError());
+		return fail();
+	}
+	if (SDL_CreateWindowAndRenderer(128, 128, 0, &window, &renderer) < 0) {
+		fprintf(stderr, "%s\n", SDL_GetError());
+		return fail();
+	}
+
 	exec_data(mem);
 	return fail(), 0;
 }
-- 
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