Refactor main loop

2 files changed, 108 insertions, 115 deletions

diff --git a/main.c b/main.c
index 407a1cd..464bcf4 100644
--- a/main.c
+++ b/main.c
@@ -1,7 +1,37 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include "platform.c"
+#include <SDL2/SDL.h>
+
+#define WINDOW_W 1280
+#define WINDOW_H 720
+
+static inline double GetCurrentTimestamp() {
+	return (double) SDL_GetTicks64() / 1000.0;
+}
+
+SDL_Texture *CreateTiledTexture(SDL_Renderer *context, const char *filename, int width, int height) {
+	SDL_Surface *texture_surface = SDL_LoadBMP(filename);
+	SDL_Texture *texture_tile = SDL_CreateTextureFromSurface(context, texture_surface);
+	int tile_w = texture_surface->w;
+	int tile_h = texture_surface->h;
+	SDL_FreeSurface(texture_surface);
+
+	SDL_Texture *texture = SDL_CreateTexture(context,
+			SDL_PIXELFORMAT_RGBA8888,
+			SDL_TEXTUREACCESS_TARGET,
+			width, height);
+	SDL_SetRenderTarget(context, texture);
+	for (int y = 0; y < height; y += tile_h) {
+		for (int x = 0; x < width; x += tile_w) {
+			SDL_Rect tile_rect = { x, y, tile_w, tile_h };
+			SDL_RenderCopy(context, texture_tile, 0, &tile_rect);
+		}
+	}
+	SDL_DestroyTexture(texture_tile);
+	SDL_SetRenderTarget(context, 0);
+	return texture;
+}
 
 void PaintMask(float *mask, float x, float y, float color, float size) {
 	for (int j = y - size; j < y + size; j++) {
@@ -17,25 +47,41 @@ void PaintMask(float *mask, float x, float y, float color, float size) {
 	}
 }
 
-void GameMain() {
-	// Terrain generation
+void GameMain(SDL_Renderer *context) {
+	SDL_Texture *background = CreateTiledTexture(context, "background.bmp", WINDOW_W, WINDOW_H);
+
+	SDL_Texture *foreground = CreateTiledTexture(context, "foreground.bmp", WINDOW_W, WINDOW_H);
+	SDL_SetTextureBlendMode(foreground, SDL_BLENDMODE_MOD);
+
+	SDL_Texture *terrain = SDL_CreateTexture(context,
+			SDL_PIXELFORMAT_RGBA8888,
+			SDL_TEXTUREACCESS_TARGET,
+			WINDOW_W, WINDOW_H);
+	SDL_SetTextureBlendMode(terrain, SDL_BLENDMODE_BLEND);
+
+	SDL_Texture *mask_texture = SDL_CreateTexture(context,
+			SDL_PIXELFORMAT_RGBA8888,
+			SDL_TEXTUREACCESS_STREAMING,
+			WINDOW_W, WINDOW_H);
+
 	float *mask = calloc(WINDOW_W * WINDOW_H, sizeof(float));
 	for (int i = 0; i < 100 * WINDOW_W; i++) {
 		mask[i] = 1.0;
 	}
 
-	// Player variables
 	float player_x = 100;
 	float player_y = 500;
 	float player_vy = 0;
 	float player_ay = -9.8;
 
-	// Timer variables
 	float old_t = 0.0;
 
-	// Event handling
 	int exit = 0;
 	while (!exit) {
+		double new_t = GetCurrentTimestamp();
+		double dt = (new_t - old_t) * 10;
+		old_t = new_t;
+
 		SDL_Event event;
 		while (SDL_PollEvent(&event)) {
 			if (event.type == SDL_QUIT) {
@@ -51,26 +97,73 @@ void GameMain() {
 			PaintMask(mask, mouse_x, WINDOW_H - mouse_y, 0.0, size);
 		}
 
-		// Time delta calculation
-		double new_t = GetCurrentTimestamp();
-		double dt = new_t - old_t;
-		old_t = new_t;
+		const Uint8 *keys = SDL_GetKeyboardState(0);
+		if (keys[SDL_SCANCODE_D]) {
+			player_x += 10 * dt;
+		}
+		if (keys[SDL_SCANCODE_A]) {
+			player_x -= 10 * dt;
+		}
 
-		// Player logic
-		if (mask[(int)player_x + (int)player_y * WINDOW_W] == 0.0) {
+		if (player_x < 0) {
+			player_x += 10 * dt;
+		} else if (player_x >= WINDOW_W) {
+			player_x -= 10 * dt;
+		}
+		if (mask[(int)player_x + (int)player_y * WINDOW_W] == 0.0 &&
+				player_y >= 0 && player_y < WINDOW_H) {
 			player_y += player_vy * dt;
 			player_vy += player_ay * dt;
 		} else {
-			player_y += 1;
+			player_y += 10 * dt;
 			player_vy = 0;
 		}
 
-		RenderScene(mask, player_x, player_y);
+		void *pixels;
+		int pitch;
+		SDL_LockTexture(mask_texture, 0, &pixels, &pitch);
+		Uint32 *p = (Uint32 *) pixels;
+		for (int j = 0; j < WINDOW_H; j++) {
+			for (int i = 0; i < WINDOW_W; i++) {
+				p[i + j * WINDOW_W] = mask[i + (WINDOW_H - j) * WINDOW_W] ? 0xffffffff : 0x00000000;
+			}
+		}
+		SDL_UnlockTexture(mask_texture);
+
+		SDL_SetRenderDrawColor(context, 40, 40, 40, 255);
+		SDL_RenderClear(context);
+		SDL_RenderCopy(context, background, 0, 0);
+		SDL_SetRenderTarget(context, terrain);
+		SDL_SetRenderDrawColor(context, 0, 0, 0, 0);
+		SDL_RenderClear(context);
+		SDL_RenderCopy(context, mask_texture, 0, 0);
+		SDL_RenderCopy(context, foreground, 0, 0);
+		SDL_SetRenderTarget(context, 0);
+		SDL_RenderCopy(context, terrain, 0, 0);
+		SDL_SetRenderDrawColor(context, 255, 0, 0, 255);
+		SDL_Rect player_rect = {player_x - 5, WINDOW_H - player_y - 10, 10, 10 };
+		SDL_RenderFillRect(context, &player_rect);
+		SDL_RenderPresent(context);
 		SDL_Delay(1);
 	}
 }
 
 int main() {
-	PlatformMain(GameMain);
+	SDL_Init(SDL_INIT_VIDEO);
+
+	SDL_Window *window = SDL_CreateWindow("Cannons",
+			SDL_WINDOWPOS_UNDEFINED,
+			SDL_WINDOWPOS_UNDEFINED,
+			WINDOW_W,
+			WINDOW_H,
+			0);
+
+	SDL_Renderer *context = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+
+	GameMain(context);
+
+	SDL_DestroyRenderer(context);
+	SDL_DestroyWindow(window);
+	SDL_Quit();
 	return 0;
 }
diff --git a/platform.c b/platform.c
deleted file mode 100644
index 24f5394..0000000
--- a/platform.c
+++ /dev/null
@@ -1,100 +0,0 @@
-#include <SDL2/SDL.h>
-
-#define WINDOW_W 1280
-#define WINDOW_H 720
-
-SDL_Renderer *context = 0;
-SDL_Texture *background = 0;
-SDL_Texture *foreground = 0;
-SDL_Texture *terrain = 0;
-SDL_Texture *mask_texture = 0;
-
-double GetCurrentTimestamp() {
-	return (double) SDL_GetTicks64() / 1000.0;
-}
-
-SDL_Texture *CreateTiledTexture(SDL_Renderer *context, const char *filename, int width, int height) {
-	SDL_Surface *texture_surface = SDL_LoadBMP(filename);
-	SDL_Texture *texture_tile = SDL_CreateTextureFromSurface(context, texture_surface);
-	int tile_w = texture_surface->w;
-	int tile_h = texture_surface->h;
-	SDL_FreeSurface(texture_surface);
-
-	SDL_Texture *texture = SDL_CreateTexture(context,
-			SDL_PIXELFORMAT_RGBA8888,
-			SDL_TEXTUREACCESS_TARGET,
-			width, height);
-	SDL_SetRenderTarget(context, texture);
-	for (int y = 0; y < height; y += tile_h) {
-		for (int x = 0; x < width; x += tile_w) {
-			SDL_Rect tile_rect = { x, y, tile_w, tile_h };
-			SDL_RenderCopy(context, texture_tile, 0, &tile_rect);
-		}
-	}
-	SDL_DestroyTexture(texture_tile);
-	SDL_SetRenderTarget(context, 0);
-	return texture;
-}
-
-void PlatformMain(void (*GameMain)(void)) {
-	SDL_Init(SDL_INIT_VIDEO);
-
-	SDL_Window *window = SDL_CreateWindow("Cannons",
-			SDL_WINDOWPOS_UNDEFINED,
-			SDL_WINDOWPOS_UNDEFINED,
-			WINDOW_W,
-			WINDOW_H,
-			0);
-
-	context = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
-
-	background = CreateTiledTexture(context, "background.bmp", WINDOW_W, WINDOW_H);
-
-	foreground = CreateTiledTexture(context, "foreground.bmp", WINDOW_W, WINDOW_H);
-	SDL_SetTextureBlendMode(foreground, SDL_BLENDMODE_MOD);
-
-	terrain = SDL_CreateTexture(context,
-			SDL_PIXELFORMAT_RGBA8888,
-			SDL_TEXTUREACCESS_TARGET,
-			WINDOW_W, WINDOW_H);
-	SDL_SetTextureBlendMode(terrain, SDL_BLENDMODE_BLEND);
-
-	mask_texture = SDL_CreateTexture(context,
-			SDL_PIXELFORMAT_RGBA8888,
-			SDL_TEXTUREACCESS_STREAMING,
-			WINDOW_W, WINDOW_H);
-
-	GameMain();
-
-	SDL_DestroyRenderer(context);
-	SDL_DestroyWindow(window);
-	SDL_Quit();
-}
-
-void RenderScene(float *mask, int player_x, int player_y) {
-	void *pixels;
-	int pitch;
-	SDL_LockTexture(mask_texture, 0, &pixels, &pitch);
-	Uint32 *p = (Uint32 *) pixels;
-	for (int j = 0; j < WINDOW_H; j++) {
-		for (int i = 0; i < WINDOW_W; i++) {
-			p[i + j * WINDOW_W] = mask[i + (WINDOW_H - j) * WINDOW_W] ? 0xffffffff : 0x00000000;
-		}
-	}
-	SDL_UnlockTexture(mask_texture);
-
-	SDL_SetRenderDrawColor(context, 40, 40, 40, 255);
-	SDL_RenderClear(context);
-	SDL_RenderCopy(context, background, 0, 0);
-	SDL_SetRenderTarget(context, terrain);
-	SDL_SetRenderDrawColor(context, 0, 0, 0, 0);
-	SDL_RenderClear(context);
-	SDL_RenderCopy(context, mask_texture, 0, 0);
-	SDL_RenderCopy(context, foreground, 0, 0);
-	SDL_SetRenderTarget(context, 0);
-	SDL_RenderCopy(context, terrain, 0, 0);
-	SDL_SetRenderDrawColor(context, 255, 0, 0, 255);
-	SDL_Rect player_rect = {player_x - 5, WINDOW_H - player_y - 10, 10, 10 };
-	SDL_RenderFillRect(context, &player_rect);
-	SDL_RenderPresent(context);
-}