Adding renderdriver header and SDL2 implementation of it

src/KW_renderdriver.h

@@ -0,0 +1,41 @@
+#ifndef RENDERDRIVER_H
+#define RENDERDRIVER_H
+
+typedef void * KW_Texture;
+typedef void * KW_Font;
+
+typedef struct KW_Rect {
+  unsigned int x;
+  unsigned int y;
+  unsigned int w;
+  unsigned int h;
+} KW_Rect;
+
+typedef struct KW_Color {
+  unsigned char r;
+  unsigned char g;
+  unsigned char b;
+  unsigned char a;
+} KW_Color;
+
+typedef struct KW_RenderDriver KW_RenderDriver;
+
+typedef enum KW_RenderDriver_TextStyle {
+  KW_TTF_STYLE_NORMAL        = 0x00,
+  KW_TTF_STYLE_BOLD          = 0x01,
+  KW_TTF_STYLE_ITALIC        = 0x02,
+  KW_TTF_STYLE_UNDERLINE     = 0x04,
+  KW_TTF_STYLE_STRIKETHROUGH = 0x08
+} KW_RenderDriver_TextStyle;
+
+struct KW_RenderDriver {
+  void (*renderCopy)(KW_RenderDriver * driver, KW_Texture src, const KW_Rect * clip, const KW_Rect * dstRect);
+  KW_Texture (*renderText)(KW_RenderDriver * driver, const KW_Font font, const char * text, KW_Color color, KW_RenderDriver_TextStyle style);
+  KW_Font (*loadFont)(KW_RenderDriver * driver, const char * fontFile, unsigned ptSize);
+  KW_Texture (*loadTexture)(KW_RenderDriver * driver, const char * textureFile);
+  void (*releaseTexture)(KW_RenderDriver * driver, KW_Texture texture);
+  void (*releaseFont)(KW_RenderDriver * driver, KW_Font font);
+  void * priv;
+};
+
+#endif

src/KW_renderdriver_sdl2.c

@@ -0,0 +1,93 @@
+#include "KW_renderdriver_sdl2.h"
+#include "KW_renderdriver.h"
+#include "SDL.h"
+#include "SDL_ttf.h"
+#include "SDL_image.h"
+
+
+typedef struct KWSDL {
+  SDL_Renderer * renderer;
+  SDL_Window * window;
+} KWSDL;
+
+static KW_Font KWSDL_loadFont(KW_RenderDriver * driver, const char * font, unsigned ptSize);
+static KW_Texture KWSDL_loadTexture(KW_RenderDriver * driver, const char * texturefile);
+static KW_Texture KWSDL_renderText(KW_RenderDriver * driver, const KW_Font font, const char * text, KW_Color color, KW_RenderDriver_TextStyle style);
+static void KWSDL_releaseTexture(KW_RenderDriver * driver, KW_Texture texture);
+static void KWSDL_releaseFont(KW_RenderDriver * driver, KW_Font font);
+static void KWSDL_renderCopy(KW_RenderDriver * driver, KW_Texture texture, const KW_Rect * src, const KW_Rect * dst);
+
+struct KW_RenderDriver * KW_CreateSDL2RenderDriver(SDL_Renderer * renderer, SDL_Window * window){
+  struct KWSDL * kwsdl = calloc(sizeof(*kwsdl), 1);
+  struct KW_RenderDriver * rd = calloc(sizeof(*rd), 1);
+
+  kwsdl->renderer = renderer;
+  kwsdl->window = window;
+
+  rd->loadFont = KWSDL_loadFont;
+  rd->loadTexture = KWSDL_loadTexture;
+  rd->renderText = KWSDL_renderText;
+  rd->releaseFont = KWSDL_releaseFont;
+  rd->releaseTexture = KWSDL_releaseTexture;
+  rd->renderCopy = KWSDL_renderCopy;
+
+  rd->priv = kwsdl;
+  return rd;
+}
+
+static KW_Font KWSDL_loadFont(KW_RenderDriver * driver, const char * font, unsigned ptSize) {
+  TTF_Font * f = TTF_OpenFont(font, ptSize);
+  (void)driver;
+  if (f == NULL) {
+    fprintf(stderr, "KW_RenderDriver_SDL: Could not load font %s: %s\n", font, TTF_GetError());
+    return NULL;
+  }
+  return f;
+}
+
+static KW_Texture KWSDL_loadTexture(KW_RenderDriver * driver, const char * texturefile) {
+  KWSDL * kwsdl = (KWSDL *) driver->priv;
+  SDL_Texture * t = IMG_LoadTexture(kwsdl->renderer, texturefile);
+  if (t == NULL) {
+    fprintf(stderr, "KW_RenderDriver_SDL: Could not load texture %s: %s\n", texturefile, IMG_GetError());
+    return NULL;
+  }
+  return t;
+}
+
+static KW_Texture KWSDL_renderText(KW_RenderDriver * driver, const KW_Font font, const char * text, KW_Color color, KW_RenderDriver_TextStyle style) {
+  KWSDL * kwsdl = (KWSDL *) driver->priv;
+  int previousstyle;
+  SDL_Color sdlcolor;
+  SDL_Surface * textsurface;
+  SDL_Texture * ret;
+
+  sdlcolor.r = color.r, sdlcolor.g = color.g, sdlcolor.b = color.b, sdlcolor.a = color.a;
+  if (font == NULL || text == NULL)
+    return NULL;
+
+  previousstyle = TTF_GetFontStyle(font);
+  TTF_SetFontStyle(font, style);
+  textsurface = TTF_RenderUTF8_Blended(font, text, sdlcolor);
+  ret = SDL_CreateTextureFromSurface(kwsdl->renderer, textsurface);
+  SDL_FreeSurface(textsurface);
+  TTF_SetFontStyle(font, previousstyle);
+  return ret;
+}
+
+static void KWSDL_releaseTexture(KW_RenderDriver * driver, KW_Texture texture) {
+  (void)driver;
+  SDL_DestroyTexture(texture);
+}
+static void KWSDL_releaseFont(KW_RenderDriver * driver, KW_Font font) {
+  (void)driver;
+  TTF_CloseFont(font);
+}
+
+static void KWSDL_renderCopy(KW_RenderDriver * driver, KW_Texture texture, const KW_Rect * src, const KW_Rect * dst) {
+  KWSDL * kwsdl = (KWSDL *) driver->priv;
+  SDL_Rect srcRect, dstRect;
+  srcRect.x = src->x; srcRect.y = src->y; srcRect.w = src->w; srcRect.h = src->h;
+  dstRect.x = dst->x; dstRect.y = dst->y; dstRect.w = dst->w; dstRect.h = dst->h;
+  SDL_RenderCopy(kwsdl->renderer, texture, &srcRect, &dstRect);
+}

src/KW_renderdriver_sdl2.h

@@ -0,0 +1,9 @@
+#ifndef KW_RENDERDRIVER_SDL2
+#define KW_RENDERDRIVER_SDL2
+
+#include "SDL.h"
+
+struct KW_RenderDriver * KW_CreateSDL2RenderDriver(SDL_Renderer * renderer, SDL_Window * window);
+
+#endif
+