graphics.c File Reference

#include <string.h>
#include <stdio.h>
#include "SDL2/SDL.h"
#include "math.h"
#include "graphics.h"
#include "texture.h"
#include "color.h"

Include dependency graph for graphics.c:

Classes
struct	graphics
	Graphics state. More...

Functions
void	swap_generic (void *v1, void *v2, size_t size)
	A mostly generic implementation of swap. More...
struct graphics *	GraphicsInit (char *title, int width, int height, int scale)
	Creates and initializes a new graphics object isntance. More...
void	GraphicsDeinit (struct graphics *g)
	De-initializes and frees memory for the given graphics object. More...
void	GraphicsBegin (struct graphics *graphics)
	Initializes the graphics subsystem for drawing routines. More...
void	GraphicsEnd (struct graphics *graphics)
	Prepares the graphics subsystem for presentation, then presents. More...
void	GraphicsClearScreen (struct graphics *graphics, unsigned int color)
	Sets all pixels in the screen to the given color. More...
void	PutPixelScaled (struct graphics *graphics, int x, int y, unsigned int color)
	Scale the pixel being drawn. More...
void	PutPixel (struct graphics *graphics, int x, int y, unsigned int color)
	Put a pixel into the graphics buffer. More...
void	GraphicsDrawLine (struct graphics *graphics, int x1, int y1, int x2, int y2, unsigned int color)
	Draws a line from (x1,y1) to (x2,y2) More...
void	GraphicsTriangleTextured (struct graphics *graphics, struct triangle tri, struct texture *texture)
	Draw a textured triangle with the given set of x and y coordinates. More...
void	GraphicsTriangleWireframe (struct graphics *graphics, struct triangle triangle, unsigned int color)
	Draw a triangle with the given set of x and y coordinates. More...
void	TriangleSolidDrawLine (struct graphics *graphics, int xmin, int xmax, int y, unsigned int color)
	Used internally by GraphicsTriangleSolid()
void	GraphicsTriangleSolid (struct graphics *graphics, struct triangle triangle, unsigned int color)
	Draw a triangle with the given set of x and y coordinates. More...

Function Documentation

GraphicsBegin()

void GraphicsBegin

(

struct graphics *

graphics

)

Initializes the graphics subsystem for drawing routines.

Internally locks streaming texture for direct manipulation.

Parameters

[in,out]

graphics

Graphics state to be manipulated

GraphicsClearScreen()

void GraphicsClearScreen	(	struct graphics *	graphics,
		unsigned int	color
	)

Sets all pixels in the screen to the given color.

Parameters

[in,out]	graphics	Graphics state to be manipulated
[in]	color	32-bit color with 8-bits per component: (R,G,B,A)

GraphicsDeinit()

void GraphicsDeinit

(

struct graphics *

graphics

)

De-initializes and frees memory for the given graphics object.

Parameters

[in,out]

graphics

The initialized opcode object to be cleaned and reclaimed

GraphicsDrawLine()

void GraphicsDrawLine	(	struct graphics *	graphics,
		int	x1,
		int	y1,
		int	x2,
		int	y2,
		unsigned int	color
	)

Draws a line from (x1,y1) to (x2,y2)

Used by GraphicsTriangleWireframe() and GraphicsTriangleSolid()

Parameters

[in,out]	graphics	Graphics state to be manipulated
[in]	x1	horizontal position of the line start.
[in]	y1	vertical position of the line start.
[in]	x2	horizontal position of the line end.
[in]	y2	vertical position of the line end.
[in]	color	color to render the line with.

GraphicsEnd()

void GraphicsEnd

(

struct graphics *

graphics

)

Prepares the graphics subsystem for presentation, then presents.

Internally unlocks streaming texture then calls presentation routines.

Parameters

[in,out]

graphics

Graphics state to be manipulated.

GraphicsInit()

struct graphics* GraphicsInit	(	char *	title,
		int	width,
		int	height,
		int	scale
	)

Creates and initializes a new graphics object isntance.

Scale can be specified as a non-negative number. This value is used to multiply both the width and the height and the pixel size of any drawing operations.

For example, specifying a scale of 2 would multiply the width by 2, the height by 2, and every pixel would be 2x2; so the total scale factor ends up being scale^2

Parameters

[in]	title	The title displayed in the window titlebar
[in]	width	Width of the display area of the window, in pixels
[in]	height	Height of the display are of the window, in pixels
[in]	scale	Size and rendering scale, natural number multiple

Returns

The initialized graphics object

GraphicsTriangleSolid()

void GraphicsTriangleSolid	(	struct graphics *	graphics,
		struct triangle	triangle,
		unsigned int	color
	)

Draw a triangle with the given set of x and y coordinates.

Fills the specified polygon with the given color.

Parameters

[in,out]	graphics	Graphics state to be changed
[in]	triangle	The triangle to draw
[in]	color	What color the solid triangle should be rendered with

See also

Source: http://www.sunshine2k.de/coding/java/TriangleRasterization/TriangleRasterization.html

GraphicsTriangleTextured()

void GraphicsTriangleTextured	(	struct graphics *	graphics,
		struct triangle	tri,
		struct texture *	texture
	)

Draw a textured triangle with the given set of x and y coordinates.

Fills the specified polygon with the given texture.

Parameters

[in,out]	graphics	Graphics state to be changed
[in]	tri	The triangle to draw
[in]	texture	What texture to sample while drawing the solid triangle

See also

Source: https://github.com/OneLoneCoder/videos/blob/master/OneLoneCoder_olcEngine3D_Part4.cpp

GraphicsTriangleWireframe()

void GraphicsTriangleWireframe	(	struct graphics *	graphics,
		struct triangle	triangle,
		unsigned int	color
	)

Draw a triangle with the given set of x and y coordinates.

Only draws the lines, doesn't fill the polygon.

Parameters

[in,out]	graphics	Graphics state to be changed
[in]	triangle	The triangle to draw
[in]	color	What color the wireframe should be rendered with

PutPixel()

void PutPixel	(	struct graphics *	graphics,
		int	x,
		int	y,
		unsigned int	color
	)

Put a pixel into the graphics buffer.

Parameters

[in,out]	graphics	Graphics state to be manipulated
[in]	x	horizontal position in display buffer (assuming no scaling)
[in]	y	vertical position in display buffer (assuming no scaling)
[in]	color	Color to put into display buffer

PutPixelScaled()

void PutPixelScaled	(	struct graphics *	graphics,
		int	x,
		int	y,
		unsigned int	color
	)

Scale the pixel being drawn.

This renders the given pixel, scaled as per graphics->scale.

When the graphics state is initialized, a width and height are specified.

Internally the graphics state multiplies both of these values by the scale and stores a buffer of the resulting size. This function allows us to treat the resulting scaled buffer as if it were the original size requested.

Parameters

[in,out]	graphics	Graphics state to be manipulated
[in]	x	horizontal position in display buffer (assuming no scaling)
[in]	y	vertical position in display buffer (assuming no scaling)
[in]	color	Color to put into display buffer

swap_generic()

void swap_generic	(	void *	v1,
		void *	v2,
		size_t	size
	)

A mostly generic implementation of swap.

Both v1 and v2 must point to data that is the same size, as specified in the size parameter.

Parameters

[in,out]	v1	first value
[in,out]	v2	second value
[in]	size	v1 and v2 must each be this size