# Spring 2021 CSE12 Lab 4 Template
######################################################
# Macros made for you (you will need to use these)
######################################################
# Macro that stores the value in %reg on the stack
# and moves the stack pointer.
.macro push(%reg)
subi $sp $sp 4
sw %reg 0($sp)
.end_macro
# Macro takes the value on the top of the stack and
# loads it into %reg then moves the stack pointer.
.macro pop(%reg)
lw %reg 0($sp)
addi $sp $sp 4
.end_macro
#################################################
# Macros for you to fill in (you will need these)
#################################################
# Macro that takes as input coordinates in the format
# (0x00XX00YY) and returns x and y separately.
# args:
# %input: register containing 0x00XX00YY
# %x: register to store 0x000000XX in
# %y: register to store 0x000000YY in
.macro getCoordinates(%input %x %y)
# YOUR CODE HERE
.end_macro
# Macro that takes Coordinates in (%x,%y) where
# %x = 0x000000XX and %y= 0x000000YY and
# returns %output = (0x00XX00YY)
# args:
# %x: register containing 0x000000XX
# %y: register containing 0x000000YY
# %output: register to store 0x00XX00YY in
.macro formatCoordinates(%output %x %y)
# YOUR CODE HERE
.end_macro
# Macro that converts pixel coordinate to address
# output = origin + 4 * (x + 128 * y)
# where origin = 0xFFFF0000 is the memory address
# corresponding to the point (0, 0), i.e. the memory
# address storing the color of the the top left pixel.
# args:
# %x: register containing 0x000000XX
# %y: register containing 0x000000YY
# %output: register to store memory address in
.macro getPixelAddress(%output %x %y)
# YOUR CODE HERE
.end_macro
.text
# prevent this file from being run as main
li $v0 10
syscall
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Subroutines defined below
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#*****************************************************
# Clear_bitmap: Given a color, will fill the bitmap
# display with that color.
# —————————————————–
# Inputs:
# $a0 = Color in format (0x00RRGGBB)
# Outputs:
# No register outputs
#*****************************************************
clear_bitmap: nop
# YOUR CODE HERE, only use t registers (and a, v where appropriate)
jr $ra
#*****************************************************
# draw_pixel: Given a coordinate in $a0, sets corresponding
# value in memory to the color given by $a1
# —————————————————–
# Inputs:
# $a0 = coordinates of pixel in format (0x00XX00YY)
# $a1 = color of pixel in format (0x00RRGGBB)
# Outputs:
# No register outputs
#*****************************************************
draw_pixel: nop
# YOUR CODE HERE, only use t registers (and a, v where appropriate)
jr $ra
#*****************************************************
# get_pixel:
# Given a coordinate, returns the color of that pixel
#—————————————————–
# Inputs:
# $a0 = coordinates of pixel in format (0x00XX00YY)
# Outputs:
# Returns pixel color in $v0 in format (0x00RRGGBB)
#*****************************************************
get_pixel: nop
# YOUR CODE HERE, only use t registers (and a, v where appropriate)
jr $ra
#*****************************************************
# draw_horizontal_line: Draws a horizontal line
# —————————————————-
# Inputs:
# $a0 = y-coordinate in format (0x000000YY)
# $a1 = color in format (0x00RRGGBB)
# Outputs:
# No register outputs
#*****************************************************
draw_horizontal_line: nop
# YOUR CODE HERE, only use t registers (and a, v where appropriate)
jr $ra
#*****************************************************
# draw_vertical_line: Draws a vertical line
# —————————————————-
# Inputs:
# $a0 = x-coordinate in format (0x000000XX)
# $a1 = color in format (0x00RRGGBB)
# Outputs:
# No register outputs
#*****************************************************
draw_vertical_line: nop
# YOUR CODE HERE, only use t registers (and a, v where appropriate)
jr $ra
#*****************************************************
# draw_crosshair: Draws a horizontal and a vertical
# line of given color which intersect at given (x, y).
# The pixel at (x, y) should be the same color before
# and after running this function.
# —————————————————–
# Inputs:
# $a0 = (x, y) coords of intersection in format (0x00XX00YY)
# $a1 = color in format (0x00RRGGBB)
# Outputs:
# No register outputs
#*****************************************************
draw_crosshair: nop
push($ra)
# HINT: Store the pixel color at $a0 before drawing the horizontal and
# vertical lines, then afterwards, restore the color of the pixel at $a0 to
# give the appearance of the center being transparent.
# Note: Remember to use push and pop in this function to save your t-registers
# before calling any of the above subroutines. Otherwise your t-registers
# may be overwritten.
# YOUR CODE HERE, only use t0-t7 registers (and a, v where appropriate)
# HINT: at this point, $ra has changed (and you’re likely stuck in an infinite loop).
# Add a pop before the below jump return (and push somewhere above) to fix this.
jr $ra