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C64: [VIC2] don't change in middle of a multi-color (double width) pixel

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This commit is contained in:
Gyorgy Szombathelyi
2020-04-16 17:32:50 +02:00
parent 4483550cc0
commit 68c5f767ad
1 changed files with 13 additions and 6 deletions
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19
cores/c64/rtl/video_vicII_656x_a.vhd
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@@ -168,6 +168,7 @@ architecture rtl of video_vicii_656x is
-- Stores colorinfo and the Pixels that are currently in shift register
signal shiftingChar : unsigned(11 downto 0);
signal shiftingPixels : unsigned(7 downto 0);
signal currentPixels : unsigned(1 downto 0);
signal shifting_ff : std_logic; -- Multicolor shift-regiter status bit.
-- Sprite work registers
@@ -913,15 +914,21 @@ calcBitmap: process(clk)
shifting_ff <= '0';
shiftingChar <= waitingChar_r;
shiftingPixels <= waitingPixels_r;
if multiColor = '0' or shifting_ff = '1' then
-- don't change in middle of a multi-color (double width) pixel
currentPixels <= waitingPixels_r(7 downto 6);
end if;
elsif multiColor = '0' then
shiftingPixels <= shiftingPixels(6 downto 0) & '0';
currentPixels <= shiftingPixels(6 downto 5);
elsif shifting_ff = '1' then
shiftingPixels <= shiftingPixels(5 downto 0) & "00";
currentPixels <= shiftingPixels(5 downto 4);
end if;
--
-- Calculate if pixel is in foreground or background
pixelBgFlag <= shiftingPixels(7);
pixelBgFlag <= currentPixels(1);
--
-- Calculate color of next pixel
@@ -929,12 +936,12 @@ calcBitmap: process(clk)
if (BMM = '0') and (ECM='0') then
if (multiColor = '0') then
-- normal character mode
if shiftingPixels(7) = '1' then
if currentPixels(1) = '1' then
pixelColor <= shiftingChar(11 downto 8);
end if;
else
-- multi-color character mode
case shiftingPixels(7 downto 6) is
case currentPixels is
when "01" => pixelColor <= B1C;
when "10" => pixelColor <= B2C;
when "11" => pixelColor <= '0' & shiftingChar(10 downto 8);
@@ -944,7 +951,7 @@ calcBitmap: process(clk)
elsif (MCM = '0') and (BMM = '0') and (ECM='1') then
-- extended-color character mode
-- multiple background colors but only 64 characters
if shiftingPixels(7) = '1' then
if currentPixels(1) = '1' then
pixelColor <= shiftingChar(11 downto 8);
else
case shiftingChar(7 downto 6) is
@@ -956,14 +963,14 @@ calcBitmap: process(clk)
end if;
elsif emulateGraphics and (MCM = '0') and (BMM = '1') and (ECM='0') then
-- highres bitmap mode
if shiftingPixels(7) = '1' then
if currentPixels(1) = '1' then
pixelColor <= shiftingChar(7 downto 4);
else
pixelColor <= shiftingChar(3 downto 0);
end if;
elsif emulateGraphics and (MCM = '1') and (BMM = '1') and (ECM='0') then
-- Multi-color bitmap mode
case shiftingPixels(7 downto 6) is
case currentPixels is
when "01" => pixelColor <= shiftingChar(7 downto 4);
when "10" => pixelColor <= shiftingChar(3 downto 0);
when "11" => pixelColor <= shiftingChar(11 downto 8);