starting on hardware sprites

arena.c

@@ -1,13 +1,14 @@
 #include "bmpload.h"
 #include "const.h"
 #include "arena.h"
+#include "system/vga.h"
 
 char arenaLayout[10][10] = {
   { 1, 1, 1, 1, 0, 0, 1, 1, 1, 1 },
-  { 1, 2, 2, 2, 0, 0, 2, 2, 2, 1 },
   { 1, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
   { 1, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
-  { 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 },
+  { 1, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
+  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
   { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
   { 1, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
   { 1, 0, 0, 0, 0, 0, 0, 0, 0, 1 },
@@ -37,9 +38,14 @@ void setupWallSprites(struct BMPImage *spritesheetImage) {
   );
 }
 
+extern void renderFloorTile(byte *);
+// push items onto stack
+#pragma aux (__cdecl) renderFloorTile "renderFloorTile_"
+
 void renderArenaTile(int x, int y) {
   char tile;
   struct SpriteRender *target;
+  byte *drawBuffer;
 
   tile = arenaLayout[y][x];
 
@@ -58,7 +64,15 @@ void renderArenaTile(int x, int y) {
   target->x = x * TILE_SIZE;
   target->y = y * TILE_SIZE;
 
-  drawSprite(target);
+  if (tile == 0) {
+    drawBuffer = getDrawBuffer();
+
+    renderFloorTile(
+      drawBuffer + target->x + target->y * VGA_DISPLAY_WIDTH
+    );
+  } else {
+    drawSprite(target);
+  }
 }
 
 char arenaRedrawRequests[ARENA_HEIGHT_TILES][ARENA_WIDTH_TILES];

bin/build_spritesheet_asm.rb

@@ -0,0 +1,174 @@
+#!/usr/bin/env ruby
+
+require 'rmagick'
+require 'yaml'
+require 'erb'
+
+data = YAML.load(File.read('spritesheet.yml'))
+
+class Sprite
+  def initialize(image:, sx:, sy:, width:, height:)
+    @image = image
+    @sx = sx
+    @sy = sy
+    @width = width
+    @height = height
+  end
+
+  def pixel_data
+    @height.times.each_with_object([]) do |y, obj|
+      obj << @width.times.map do |x|
+        color = @image.pixel_color(x + @sx, y + @sy)
+
+        colormap.find_index { |c| c == color }
+      end
+    end
+  end
+
+  private
+
+  def colormap
+    @colormap ||= @image.colors.times.map do |i|
+      Magick::Pixel.from_color(@image.colormap(i))
+    end
+  end
+end
+
+MovBytePtr = Data.define(:offset, :data)
+
+ASM_TEMPLATE = <<~ASM
+  <% sprites.each  do |sprite| %>
+  PUBLIC <%= sprite.exported_name %><% end %>
+
+  .386
+  .model flat,c
+
+  .CODE
+
+  <% sprites.each  do |sprite| %>
+  <%= sprite.exported_name %>:
+    push ebp
+    mov ebp, esp
+    push ebx
+
+    mov eax, [ebp + 8]
+
+    <% sprite.bytes.each  do |byte| %>
+    mov BYTE PTR [eax + <%= byte.offset %>], <%= byte.data %><% end %>
+
+    pop ebx
+    pop ebp
+    ret
+
+  <% end  %>
+  end
+ASM
+
+C_TEMPLATE = <<~C
+  <% sprites.each  do |sprite| %>
+  extern void <%= sprite.function_name %>(byte *);
+  #pragma aux (__cdecl) <%= sprite.function_name %> "<%= sprite.exported_name %>"
+  <% end  %>
+C
+
+class AssemblerSprite
+  def initialize(
+    name:,
+    pixel_data:,
+    screen_width:,
+    transparent_color:,
+    offset_x:,
+    offset_y:,
+    prefix:
+  )
+    @name = name
+    @pixel_data = pixel_data
+    @screen_width = screen_width
+    @transparent_color = transparent_color
+    @offset_x = offset_x
+    @offset_y = offset_y
+    @prefix = prefix
+  end
+
+  def exported_name
+    "#{function_name}_"
+  end
+
+  def function_name
+    "#{@prefix}_#{@name}"
+  end
+
+  def bytes
+    return @bytes if defined?(@bytes)
+
+    bytes = []
+
+    @pixel_data.each_with_index do |row, y|
+      row.each_with_index do |column, x|
+        next if @pixel_data[y][x] == @transparent_color
+
+        bytes << MovBytePtr.new(
+          data: @pixel_data[y][x],
+          offset: x - @offset_x + (y - @offset_y) * @screen_width
+        )
+      end
+    end
+
+    bytes
+  end
+end
+
+Screen = Data.define(:width, :transparent_color)
+SpriteData = Data.define(:image, :name, :position, :dimensions, :offset, :prefix)
+
+screen = Screen.new(
+  width: data["screen"]["width"],
+  transparent_color: data["screen"]["transparentColor"]
+)
+
+sprite_data = []
+
+data["files"].each do |spritesheet|
+  image = Magick::Image.read(spritesheet["file"]).first
+
+  spritesheet["sprites"].each do |name, details|
+    sprite_data << SpriteData.new(
+      image:,
+      name:,
+      prefix: spritesheet["prefix"],
+      position: details["position"],
+      dimensions: details["dimensions"],
+      offset: details["offset"]
+    )
+  end
+end
+
+sprites = sprite_data.map do |sd|
+  sprite = Sprite.new(
+    image: sd.image,
+    sx: sd.position[0],
+    sy: sd.position[1],
+    width: sd.dimensions[0],
+    height: sd.dimensions[1],
+  )
+
+  AssemblerSprite.new(
+    name: sd.name,
+    prefix: sd.prefix,
+    pixel_data: sprite.pixel_data,
+    screen_width: screen.width,
+    transparent_color: screen.transparent_color,
+    offset_x: sd.offset[0],
+    offset_y: sd.offset[1],
+  )
+end
+
+File.open('sprites.asm', 'w') do |fh|
+  fh.puts ERB.new(ASM_TEMPLATE).result_with_hash(sprites:)
+end
+
+File.open('sprites.h', 'w') do |fh|
+  fh.puts ERB.new(C_TEMPLATE).result_with_hash(sprites:)
+end
+
+puts "sprites.{asm,h} written"

game.c

@@ -331,16 +331,11 @@ int currentSpeedCalc = 0;
 double averageSpeedCalc;
 clock_t startTime;
 
-extern int doAThing(int);
+// non cdecl is put params into eax, ebx, and ecx
-#pragma aux (__cdecl) doAThing "doAThing_"
 
 int main(void) {
   int keepRunning = 1;
 
-  fprintf(stderr, "%d\n", doAThing(1000));
-
-  return 0;
-
   if (setupGame()) return 1;
 
   maybeSpawnEnemy();

makefile

@@ -10,6 +10,9 @@ system/system.lib: .SYMBOLIC
 .c.o:
 	wcc386 -q -bt=dos $<
 
+.asm.o:
+	wasm $<
+
 game.exe: $(obj) system/system.lib
   wcl386 -q -bt=dos -l=dos4g $(obj) system/system.lib
 

sprites.h

@@ -0,0 +1,22 @@
+
+extern void sprite_arenaWallTop(byte *);
+#pragma aux (__cdecl) sprite_arenaWallTop "sprite_arenaWallTop_"
+
+extern void sprite_arenaWallSide(byte *);
+#pragma aux (__cdecl) sprite_arenaWallSide "sprite_arenaWallSide_"
+
+extern void sprite_arenaFloor(byte *);
+#pragma aux (__cdecl) sprite_arenaFloor "sprite_arenaFloor_"
+
+extern void sprite_rabbit(byte *);
+#pragma aux (__cdecl) sprite_rabbit "sprite_rabbit_"
+
+extern void sprite_mouse(byte *);
+#pragma aux (__cdecl) sprite_mouse "sprite_mouse_"
+
+extern void sprite_bullet(byte *);
+#pragma aux (__cdecl) sprite_bullet "sprite_bullet_"
+
+extern void sprite_enemy(byte *);
+#pragma aux (__cdecl) sprite_enemy "sprite_enemy_"
+

spritesheet.yml

@@ -0,0 +1,35 @@
+screen:
+  width: 320
+  transparentColor: 0
+files:
+  - file: sprtsht.bmp
+    prefix: "sprite"
+    sprites:
+      arenaWallTop:
+        position: [0, 0]
+        dimensions: [20, 20]
+        offset: [10, 10]
+      arenaWallSide:
+        position: [20, 0]
+        dimensions: [20, 20]
+        offset: [0, 0]
+      arenaFloor:
+        position: [40, 0]
+        dimensions: [20, 20]
+        offset: [0, 0]
+      rabbit:
+        position: [0, 20]
+        dimensions: [16, 16]
+        offset: [8, 8]
+      mouse:
+        position: [16, 20]
+        dimensions: [8, 8]
+        offset: [4, 4]
+      bullet:
+        position: [16, 28]
+        dimensions: [4, 4]
+        offset: [1, 1]
+      enemy:
+        position: [0, 20]
+        dimensions: [16, 16]
+        offset: [8, 8]

system/vga.c

@@ -22,7 +22,7 @@ byte *initializeDrawBuffer() {
 }
 
 void copyDrawBufferToDisplay() {
-  memcpy(VGA, drawBuffer, 320 * 200);
+  memcpy(VGA, drawBuffer, VGA_DISPLAY_WIDTH * VGA_DISPLAY_HEIGHT);
 }
 
 void freeDrawBuffer() {

test.asm

@@ -1,10 +1,11 @@
-PUBLIC doAThing_
+#PUBLIC doAThing_
+#PUBLIC renderTopTile_
+PUBLIC renderFloorTile_
 
 .386
 .model flat,c
 
-_TEXT segment byte public 'CODE'
+.CODE
-
 doAThing_:
   push ebp
   mov ebp, esp
@@ -14,6 +15,53 @@ doAThing_:
   pop ebp
   ret
 
-_TEXT ends
+renderTopTile_:
+  push ebp
+  mov ebp, esp
+  push ebx
+
+  mov eax, [ebp + 8]
+  mov ebx, 20
+
+_renderNextLine:
+  mov DWORD PTR [eax], 02020202h
+  mov DWORD PTR [eax + 4], 02020202h
+  mov DWORD PTR [eax + 8], 02020202h
+  mov DWORD PTR [eax + 12], 02020202h
+  mov DWORD PTR [eax + 16], 02020202h
+
+  add eax, 320
+  dec ebx
+  cmp ebx, 0
+  jne _renderNextLine
+
+  pop ebx
+  pop ebp
+  ret
+
+renderFloorTile_:
+  push ebp
+  mov ebp, esp
+  push ebx
+
+  mov eax, [ebp + 8]
+  mov ebx, 20
+
+_renderNextFloorLine:
+  mov DWORD PTR [eax], 04040404h
+  mov DWORD PTR [eax + 4], 04040404h
+  mov DWORD PTR [eax + 8], 04040404h
+  mov DWORD PTR [eax + 12], 04040404h
+  mov DWORD PTR [eax + 16], 04040404h
+
+  add eax, 320
+  dec ebx
+  cmp ebx, 0
+  jne _renderNextFloorLine
+
+_done:
+  pop ebx
+  pop ebp
+  ret
 
 end