From f7fd33e60daa39f419712cace12f006ed90558b4 Mon Sep 17 00:00:00 2001
From: "adrian.spycher" <adrian.spycher@etu.hesge.ch>
Date: Tue, 29 Oct 2024 10:08:46 +0100
Subject: [PATCH] feat: add gfx wrapper
---
vmm/Makefile | 3 +-
vmm/gfx.c | 202 +++++++++++++++++++++++++++++++++++++++++++++++++++
vmm/gfx.h | 54 ++++++++++++++
3 files changed, 258 insertions(+), 1 deletion(-)
create mode 100644 vmm/gfx.c
create mode 100644 vmm/gfx.h
diff --git a/vmm/Makefile b/vmm/Makefile
index 64c86d3..e900610 100644
--- a/vmm/Makefile
+++ b/vmm/Makefile
@@ -1,11 +1,12 @@
CC=gcc -std=gnu17 -Wall -Wextra -MMD -Ishared -I../.. -I..
+LIBS=-lSDL2 -lSDL2_image
C_SRCS=$(shell find . -name "*.c")
C_OBJS=$(C_SRCS:.c=.o)
C_DEPS=$(C_OBJS:%.o=%.d)
$(OUT): $(C_OBJS)
- $(CC) $^ -o $@
+ $(CC) $^ -o $@ $(LIBS)
%.o: %.c
$(CC) -c $< -o $@
diff --git a/vmm/gfx.c b/vmm/gfx.c
new file mode 100644
index 0000000..03acb31
--- /dev/null
+++ b/vmm/gfx.c
@@ -0,0 +1,202 @@
+/// @file gfx.c
+/// @author Florent Gluck
+/// @date 2016-2024
+/// Helper routines for super simple graphics rendering.
+/// Requires the SDL2 library.
+
+#include "gfx.h"
+#include <signal.h>
+
+/// Create a fullscreen graphic window.
+/// @param title window title.
+/// @param width window's width in pixels.
+/// @param height window's height in pixels.
+/// @return a pointer to the graphic context or NULL if it failed.
+gfx_context_t* gfx_create(char *title, int width, int height) {
+ if (SDL_Init(SDL_INIT_VIDEO) != 0) {
+ fprintf(stderr, "%s", SDL_GetError());
+ goto error;
+ }
+ // Restore SIGINT's default behavior so that we can use CTRL-C to stop the program
+ struct sigaction act;
+ memset(&act, 0, sizeof(act));
+ act.sa_handler = SIG_DFL;
+ if (sigaction(SIGINT, &act, NULL) < 0) {
+ perror("sigaction");
+ exit(1);
+ }
+
+ // These a just for reference:
+ // SDL_SetHint(SDL_HINT_NO_SIGNAL_HANDLERS, "1");
+ // SDL_SetHint(SDL_HINT_RENDER_DRIVER, "software"); // opengl, opengles2, software
+ // SDL_SetHint(SDL_HINT_RENDER_OPENGL_SHADERS, "0");
+ // SDL_SetHint(SDL_HINT_RENDER_VSYNC, "0");
+ // SDL_SetHint(SDL_HINT_VIDEO_X11_NET_WM_PING, "0");
+ // SDL_SetHint(SDL_HINT_VIDEO_X11_XVIDMODE, "0");
+
+ SDL_Window *window = SDL_CreateWindow(title, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, width, height, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
+ SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+ SDL_Texture *background_texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, width, height);
+
+ gfx_context_t *ctxt = malloc(sizeof(gfx_context_t));
+
+ // Retrieve the background texture's pitch
+ uint8_t *unused;
+ SDL_LockTexture(background_texture, NULL, (void **)&unused, &ctxt->pitch);
+ SDL_UnlockTexture(background_texture);
+
+ pixel_t *background = malloc(ctxt->pitch*height);
+ if (!window || !renderer || !background_texture || !background || !ctxt) goto error;
+
+ ctxt->renderer = renderer;
+ ctxt->background_texture = background_texture;
+ ctxt->window = window;
+ ctxt->width = width;
+ ctxt->height = height;
+ ctxt->background = background;
+
+ SDL_ShowCursor(SDL_DISABLE);
+ gfx_background_clear(ctxt, GFX_COL_BLACK);
+ return ctxt;
+
+error:
+ return NULL;
+}
+
+/// Draw a pixel in the background buffer.
+/// @param ctxt graphic context.
+/// @param x x coordinate of the pixel.
+/// @param y y coordinate of the pixel.
+/// @param color pixel color.
+void gfx_background_putpixel(gfx_context_t *ctxt, int x, int y, pixel_t color) {
+ if (x < ctxt->width && y < ctxt->height) {
+ ctxt->background[ctxt->pitch/sizeof(pixel_t)*y+x] = color;
+ }
+}
+
+/// Clear the background buffer.
+/// @param ctxt graphic context.
+/// @param color fill color.
+void gfx_background_clear(gfx_context_t *ctxt, pixel_t color) {
+ for (int j = 0; j < ctxt->height; j++) {
+ for (int i = 0; i < ctxt->width; i++) {
+ ctxt->background[ctxt->pitch/sizeof(pixel_t)*j+i] = color;
+ }
+ }
+}
+
+/// Copy the background buffer to the display buffer.
+/// @param ctxt graphic context.
+void gfx_background_update(gfx_context_t *ctxt) {
+ SDL_UpdateTexture(ctxt->background_texture, NULL, ctxt->background, ctxt->width*sizeof(pixel_t));
+ SDL_RenderCopy(ctxt->renderer, ctxt->background_texture, NULL, NULL);
+}
+
+/// Show the display buffer.
+/// @param ctxt graphic context.
+void gfx_present(gfx_context_t *ctxt) {
+ SDL_RenderPresent(ctxt->renderer);
+}
+
+/// Destroy a graphic window.
+/// @param ctxt graphic context.
+void gfx_destroy(gfx_context_t *ctxt) {
+ SDL_ShowCursor(SDL_ENABLE);
+ SDL_DestroyTexture(ctxt->background_texture);
+ SDL_DestroyRenderer(ctxt->renderer);
+ SDL_DestroyWindow(ctxt->window);
+ free(ctxt->background);
+ ctxt->background_texture = NULL;
+ ctxt->renderer = NULL;
+ ctxt->window = NULL;
+ ctxt->background = NULL;
+ SDL_Quit();
+ free(ctxt);
+}
+
+/// If a key was pressed, returns its key code.
+/// IMPORTANT: This is a non-blocking call!
+/// List of key codes: https://wiki.libsdl.org/SDL_Keycode
+/// @return the key that was pressed or 0 if none was pressed.
+SDL_Keycode gfx_keypressed() {
+ SDL_Event event;
+ if (SDL_PollEvent(&event)) {
+ if (event.type == SDL_KEYDOWN)
+ return event.key.keysym.sym;
+ }
+ return 0;
+}
+
+/// Load a sprite from an image file (png, jpg, etc.).
+/// @param ctxt graphic context.
+/// @param filename path to the file to load.
+/// @return a pointer to the sprite or NULL in case of failure.
+/// When not needed anymore, deallocate it with gfx_sprite_destroy.
+SDL_Texture *gfx_sprite_load(gfx_context_t *ctxt, char *filename) {
+ SDL_Surface *sprite_surface = IMG_Load(filename);
+ // Failed loading sprite.
+ if (!sprite_surface) {
+ return NULL;
+ }
+
+ SDL_Texture *sprite_texture = SDL_CreateTextureFromSurface(ctxt->renderer, sprite_surface);
+ if (!sprite_texture) {
+ return NULL;
+ }
+ SDL_FreeSurface(sprite_surface); // Only the texture is needed
+
+ return sprite_texture;
+}
+
+/// Create a sprite from in-memory RGBA8888 pixels.
+/// @param ctxt graphic context.
+/// @param pixels array of pixels composing the sprite.
+/// @param width sprite's width in pixels.
+/// @param height sprite's height in pixels.
+/// @return a pointer to the sprite or NULL in case of failure.
+/// When not needed anymore, deallocate it with gfx_sprite_destroy.
+SDL_Texture *gfx_sprite_create(gfx_context_t *ctxt, uint8_t *pixels, int width, int height) {
+ SDL_Texture *tex = SDL_CreateTexture(ctxt->renderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STREAMING, width, height);
+ if (!tex) {
+ return NULL;
+ }
+
+ // Force renderer to use alpha blending when rendering the sprite.
+ SDL_SetTextureBlendMode(tex, SDL_BLENDMODE_BLEND);
+
+ pixel_t *dst_pixels;
+ pixel_t *src_pixels = (pixel_t *)pixels;
+ int pitch;
+ if (SDL_LockTexture(tex, NULL, (void **)&dst_pixels, &pitch) != 0) {
+ SDL_DestroyTexture(tex);
+ return NULL;
+ }
+ for (int j = 0; j < height; j++) {
+ for (int i = 0; i < width; i++) {
+ dst_pixels[pitch/sizeof(pixel_t)*j+i] = *src_pixels;
+ src_pixels++;
+ }
+ }
+ SDL_UnlockTexture(tex);
+
+ return tex;
+}
+
+/// Destroy a sprite that was loaded/created with gfx_sprite_load/gfx_sprite_create.
+/// @param ctxt graphic context.
+/// @param sprite the sprite (texture) to destroy.
+void gfx_sprite_destroy(SDL_Texture *sprite) {
+ SDL_DestroyTexture(sprite);
+}
+
+/// Render a sprite at the specified position.
+/// @param context graphic context.
+/// @param sprite the sprite (texture) to render.
+/// @param x sprite's x coordinate.
+/// @param y sprite's y coordinate.
+/// @param sprite_width sprite's display width in pixels.
+/// @param sprite_height sprite's display height in pixels.
+void gfx_sprite_render(gfx_context_t *ctxt, SDL_Texture *sprite, int x, int y, int sprite_width, int sprite_height) {
+ SDL_Rect dst_rect = { x, y, sprite_width, sprite_height };
+ SDL_RenderCopy(ctxt->renderer, sprite, NULL, &dst_rect);
+}
diff --git a/vmm/gfx.h b/vmm/gfx.h
new file mode 100644
index 0000000..7e2c646
--- /dev/null
+++ b/vmm/gfx.h
@@ -0,0 +1,54 @@
+#ifndef _GFX_H_
+#define _GFX_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_image.h>
+
+#define GFX_RGB(r,g,b) ((pixel_t){b,g,r,0})
+
+#define GFX_COL_BLACK GFX_RGB(0,0,0)
+#define GFX_COL_RED GFX_RGB(0,0,255)
+#define GFX_COL_GREEN GFX_RGB(0,255,0)
+#define GFX_COL_BLUE GFX_RGB(255,0,0)
+#define GFX_COL_CYAN GFX_RGB(255,255,0)
+#define GFX_COL_PURPLE GFX_RGB(255,0,255)
+#define GFX_COL_YELLOW GFX_RGB(0,255,255)
+#define GFX_COL_WHITE GFX_RGB(255,255,255)
+
+// Structure of a pixel: 32-bits (ARGB)
+typedef struct __attribute__ ((__packed__)) {
+ uint8_t b;
+ uint8_t g;
+ uint8_t r;
+ uint8_t a;
+} pixel_t;
+
+typedef struct {
+ SDL_Window *window;
+ SDL_Renderer *renderer;
+ SDL_Texture *background_texture;
+ pixel_t *background;
+ int pitch;
+ int width;
+ int height;
+} gfx_context_t;
+
+gfx_context_t* gfx_create(char *text, int width, int height);
+void gfx_destroy(gfx_context_t *ctxt);
+
+void gfx_background_putpixel(gfx_context_t *ctxt, int x, int y, pixel_t color);
+void gfx_background_clear(gfx_context_t *ctxt, pixel_t color);
+void gfx_background_update(gfx_context_t *ctxt);
+
+SDL_Texture *gfx_sprite_load(gfx_context_t *ctxt, char *filename);
+SDL_Texture *gfx_sprite_create(gfx_context_t *ctxt, uint8_t *pixels, int width, int height);
+void gfx_sprite_destroy(SDL_Texture *sprite);
+void gfx_sprite_render(gfx_context_t *ctxt, SDL_Texture *sprite, int x, int y, int sprite_width, int sprite_height);
+
+void gfx_present(gfx_context_t *ctxt);
+
+SDL_Keycode gfx_keypressed();
+
+#endif
--
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