Implement basic breakout

samples/pong/src/main.c

@@ -1,92 +1,68 @@
-/************************************************************//**
-*
-*	@file: wasm_main.cpp
-*	@author: Martin Fouilleul
-*	@date: 14/08/2022
-*	@revision:
-*
-*****************************************************************/
-
 #include<keys.h>
 #include<graphics.h>
 
 #include<orca.h>
 
-#define M_PI 3.14159265358979323846
+#define NUM_BLOCKS_PER_ROW 7
+#define NUM_BLOCKS 42 // 7 * 6
+
+#define BLOCKS_WIDTH 810.0f
+#define BLOCK_HEIGHT 30.0f
+#define BLOCKS_PADDING 15.0f
+#define BLOCKS_BOTTOM 300.0f
+const f32 BLOCK_WIDTH = (BLOCKS_WIDTH - ((NUM_BLOCKS_PER_ROW + 1) * BLOCKS_PADDING)) / NUM_BLOCKS_PER_ROW;
 
 const mg_color paddleColor = {1, 0, 0, 1};
-mp_rect paddle = {200, 40, 200, 40};
+mp_rect paddle = {BLOCKS_WIDTH/2 - 100, 40, 200, 40};
 
 const mg_color ballColor = {1, 1, 0, 1};
-mp_rect ball = {200, 200, 60, 60};
+mp_rect ball = {200, 200, 20, 20};
 
-vec2 velocity = {10, 10};
+vec2 velocity = {5, 5};
+
+int blockHealth[NUM_BLOCKS];
 
 vec2 frameSize = {100, 100};
 
 bool leftDown = false;
 bool rightDown = false;
 
-mg_canvas canvas;
 mg_surface surface;
+mg_canvas canvas;
+mg_image waterImage;
 mg_image ballImage;
 mg_image paddleImage;
 mg_font pongFont;
 
+// TODO(ben): Why is this here? Why isn't it forward-declared by some header?
 mg_surface mg_surface_main(void);
 
+mp_rect blockRect(int i);
+int checkCollision(mp_rect block);
+
+str8 loadFile(mem_arena* arena, str8 filename) {
+    file_handle file = file_open(filename, FILE_ACCESS_READ, 0);
+    if(file_last_error(file) != IO_OK)
+    {
+        log_error("Couldn't open file %s\n", str8_to_cstring(mem_scratch(), filename));
+    }
+    u64 size = file_size(file);
+    char* buffer = mem_arena_alloc(arena, size);
+    file_read(file, size, buffer);
+    file_close(file);
+    return str8_from_buffer(size, buffer);
+}
+
 ORCA_EXPORT void OnInit(void)
 {
-	//TODO create surface for main window
     surface = mg_surface_main();
     canvas = mg_canvas_create();
 
-	log_info("try allocating\n");
+    waterImage = mg_image_create_from_data(surface, loadFile(mem_scratch(), STR8("/underwater.jpg")), false);
+    ballImage = mg_image_create_from_data(surface, loadFile(mem_scratch(), STR8("/ball.png")), false);
+    paddleImage = mg_image_create_from_data(surface, loadFile(mem_scratch(), STR8("/wall.png")), false);
 
-	char* foo = malloc(1024);
+    str8 fontStr = loadFile(mem_scratch(), STR8("/Literata-SemiBoldItalic.ttf"));
-	free(foo);
-
-	log_info("allocated and freed 1024 bytes\n");
-
-	//NOTE: load ball texture
-	{
-		file_handle file = file_open(STR8("/ball.png"), FILE_ACCESS_READ, 0);
-		if(file_last_error(file) != IO_OK)
-		{
-			log_error("Couldn't open file ball.png\n");
-		}
-		u64 size = file_size(file);
-		char* buffer = mem_arena_alloc(mem_scratch(), size);
-		file_read(file, size, buffer);
-		file_close(file);
-		ballImage = mg_image_create_from_data(surface, str8_from_buffer(size, buffer), false);
-	}
-
-	//NOTE: load paddle texture
-	{
-		file_handle file = file_open(STR8("/wall.png"), FILE_ACCESS_READ, 0);
-		if(file_last_error(file) != IO_OK)
-		{
-			log_error("Couldn't open file wall.png\n");
-		}
-		u64 size = file_size(file);
-		char* buffer = mem_arena_alloc(mem_scratch(), size);
-		file_read(file, size, buffer);
-		file_close(file);
-		paddleImage = mg_image_create_from_data(surface, str8_from_buffer(size, buffer), false);
-	}
-
-	//NOTE: load paddle texture
-	{
-		file_handle file = file_open(STR8("/Literata-SemiBoldItalic.ttf"), FILE_ACCESS_READ, 0);
-		if(file_last_error(file) != IO_OK)
-		{
-			log_error("Couldn't open file Literata-SemiBoldItalic.ttf\n");
-		}
-		u64 size = file_size(file);
-		char* buffer = mem_arena_alloc(mem_scratch(), size);
-		file_read(file, size, buffer);
-		file_close(file);
     unicode_range ranges[5] = {UNICODE_RANGE_BASIC_LATIN,
                                UNICODE_RANGE_C1_CONTROLS_AND_LATIN_1_SUPPLEMENT,
                                UNICODE_RANGE_LATIN_EXTENDED_A,
@@ -94,7 +70,10 @@ ORCA_EXPORT void OnInit(void)
                                UNICODE_RANGE_SPECIALS};
     // NOTE(ben): Weird that images are "create from data" but fonts are "create from memory"
     // TODO: Decide whether we're using strings or explicit pointer + length
-		pongFont = mg_font_create_from_memory(size, (byte*)buffer, 5, ranges);
+    pongFont = mg_font_create_from_memory(fontStr.len, (byte*)fontStr.ptr, 5, ranges);
+
+    for (int i = 0; i < NUM_BLOCKS; i++) {
+        blockHealth[i] = 2;
     }
 
     mem_arena_clear(mem_scratch());
@@ -175,15 +154,15 @@ ORCA_EXPORT void OnFrameRefresh(void)
 
     if(ball.x + ball.w >= frameSize.x)
     {
-		velocity.x = -10;
+        velocity.x = -velocity.x;
     }
     if(ball.x <= 0)
     {
-		velocity.x = +10;
+        velocity.x = -velocity.x;
     }
     if(ball.y + ball.h >= frameSize.y)
     {
-		velocity.y = -10;
+        velocity.y = -velocity.y;
     }
 
     if(ball.y <= paddle.y + paddle.h
@@ -203,28 +182,67 @@ ORCA_EXPORT void OnFrameRefresh(void)
         ball.y = frameSize.y/2. - ball.h;
     }
 
+    for (int i = 0; i < NUM_BLOCKS; i++) {
+        if (blockHealth[i] <= 0) {
+            continue;
+        }
+
+        mp_rect r = blockRect(i);
+        int result = checkCollision(r);
+        if (result) {
+            log_info("Collision! direction=%d", result);
+            blockHealth[i] -= 1;
+
+            f32 vx = velocity.x;
+            f32 vy = velocity.y;
+
+            switch (result) {
+            case 1:
+            case 5:
+                velocity.y = -vy;
+                break;
+            case 3:
+            case 7:
+                velocity.x = -vx;
+                break;
+            case 2:
+            case 6:
+                velocity.x = -vy;
+                velocity.y = -vx;
+                break;
+            case 4:
+            case 8:
+                velocity.x = vy;
+                velocity.y = vx;
+                break;
+            }
+        }
+
+    }
+
     mg_canvas_set_current(canvas);
 
-	mg_set_color_rgba(0, 1, 1, 1);
+    mg_set_color_rgba(10.0f/255.0f, 31.0f/255.0f, 72.0f/255.0f, 1);
     mg_clear();
 
     mg_mat2x3 transform = {1, 0, 0,
                            0, -1, frameSize.y};
 
     mg_matrix_push(transform);
+    {
+        mg_set_color_rgba(0.9, 0.9, 0.9, 1);
+        for (int i = 0; i < NUM_BLOCKS; i++) {
+            if (blockHealth[i] <= 0) {
+                continue;
+            }
+
+            mp_rect r = blockRect(i);
+            mg_rectangle_fill(r.x, r.y, r.w, r.h);
+        }
 
         mg_image_draw(paddleImage, paddle);
-	/*
-	mg_set_color(paddleColor);
-	mg_rectangle_fill(paddle.x, paddle.y, paddle.w, paddle.h);
-	*/
-
         mg_image_draw(ballImage, ball);
-	/*
+    }
-	mg_set_color(ballColor);
-	mg_circle_fill(ball.x+ball.w/2, ball.y + ball.w/2, ball.w/2.);
-	*/
-
     mg_matrix_pop();
 
     mg_set_color_rgba(0, 0, 0, 1);
@@ -243,3 +261,139 @@ ORCA_EXPORT void OnFrameRefresh(void)
     mg_render(surface, canvas);
     mg_surface_present(surface);
 }
+
+mp_rect blockRect(int i) {
+    int row = i / NUM_BLOCKS_PER_ROW;
+    int col = i % NUM_BLOCKS_PER_ROW;
+    return (mp_rect){
+        BLOCKS_PADDING + (BLOCKS_PADDING + BLOCK_WIDTH) * col,
+        BLOCKS_BOTTOM + (BLOCKS_PADDING + BLOCK_HEIGHT) * row,
+        BLOCK_WIDTH,
+        BLOCK_HEIGHT
+    };
+}
+
+// Returns a cardinal direction 1-8 for the collision with the block, or zero
+// if no collision. 1 is straight up and directions proceed clockwise.
+int checkCollision(mp_rect block) {
+    // Note that all the logic for this game has the origin in the bottom left.
+
+    f32 ballx2 = ball.x + ball.w;
+    f32 bally2 = ball.y + ball.h;
+    f32 blockx2 = block.x + block.w;
+    f32 blocky2 = block.y + block.h;
+
+    if (
+        ballx2 < block.x
+        || blockx2 < ball.x
+        || bally2 < block.y
+        || blocky2 < ball.y
+    ) {
+        // Ball is fully outside block
+        return 0;
+    }
+
+    // if (
+    //     (block.x <= ball.x && ballx2 <= blockx2)
+    //     && (block.y <= ball.y && bally2 <= blocky2)
+    // ) {
+    //     // Ball is fully inside block; do not consider as a collision
+    //     return 0;
+    // }
+
+    // If moving right, the ball can bounce off its top right corner, right
+    // side, or bottom right corner. Corner bounces occur if the block's bottom
+    // left corner is in the ball's top right quadrant, or if the block's top
+    // left corner is in the ball's bottom left quadrant. Otherwise, an edge
+    // bounce occurs if the block's left edge falls in either of the ball's
+    // right quadrants.
+    //
+    // This logic generalizes to other directions.
+    //
+    // We assume significant tunneling can't happen.
+
+    vec2 ballCenter = (vec2){ball.x + ball.w/2, ball.y + ball.h/2};
+    vec2 blockCenter = (vec2){block.x + block.w/2, block.y + block.h/2};
+
+    // Moving right
+    if (velocity.x > 0) {
+        // Ball's top right corner
+        if (
+            ballCenter.x <= block.x && block.x <= ballx2
+            && ballCenter.y <= block.y && block.y <= bally2
+        ) { return 2; }
+
+        // Ball's bottom right corner
+        if (
+            ballCenter.x <= block.x && block.x <= ballx2
+            && ball.y <= blocky2 && blocky2 <= ballCenter.y
+        ) { return 4; }
+
+        // Ball's right edge
+        if (
+            ballCenter.x <= block.x && block.x <= ballx2
+        ) { return 3; }
+    }
+
+    // Moving up
+    if (velocity.y > 0) {
+        // Ball's top left corner
+        if (
+            ball.x <= blockx2 && blockx2 <= ballCenter.x
+            && ballCenter.y <= block.y && block.y <= bally2
+        ) { return 8; }
+
+        // Ball's top right corner
+        if (
+            ballCenter.x <= block.x && block.x <= ballx2
+            && ballCenter.y <= block.y && block.y <= bally2
+        ) { return 2; }
+
+        // Ball's top edge
+        if (
+            ballCenter.y <= block.y && block.y <= bally2
+        ) { return 1; }
+    }
+
+    // Moving left
+    if (velocity.x < 0) {
+        // Ball's bottom left corner
+        if (
+            ball.x <= blockx2 && blockx2 <= ballCenter.x
+            && ball.y <= blocky2 && blocky2 <= ballCenter.y
+        ) { return 6; }
+
+        // Ball's top left corner
+        if (
+            ball.x <= blockx2 && blockx2 <= ballCenter.x
+            && ballCenter.y <= block.y && block.y <= bally2
+        ) { return 8; }
+
+        // Ball's left edge
+        if (
+            ball.x <= blockx2 && blockx2 <= ballCenter.x
+        ) { return 7; }
+    }
+
+    // Moving down
+    if (velocity.y < 0) {
+        // Ball's bottom right corner
+        if (
+            ballCenter.x <= block.x && block.x <= ballx2
+            && ball.y <= blocky2 && blocky2 <= ballCenter.y
+        ) { return 4; }
+
+        // Ball's bottom left corner
+        if (
+            ball.x <= blockx2 && blockx2 <= ballCenter.x
+            && ball.y <= blocky2 && blocky2 <= ballCenter.y
+        ) { return 6; }
+
+        // Ball's bottom edge
+        if (
+            ball.y <= blocky2 && blocky2 <= ballCenter.y
+        ) { return 5; }
+    }
+
+    return 0;
+}