williamjcm/small3dlib
1
0
Fork 0
mirror of https://git.coom.tech/drummyfish/small3dlib.git synced 2024-11-23 20:59:58 +01:00
Code Activity

Refactor

Browse source
This commit is contained in:
Miloslav Číž 2019-06-04 22:59:38 +02:00
parent d0f504bc5d
commit f4a4ca06b4
2 changed files with 102 additions and 106 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

202
small3dlib.h
View file

@ -1,5 +1,5 @@
#ifndef S3L_H
#define S3L_H
#ifndef SMALL3DLIB_H
#define SMALL3DLIB_H
/*
WIP
@ -126,30 +126,44 @@
// ---------------
#ifndef S3L_RESOLUTION_X
#define S3L_RESOLUTION_X 640 ///< Redefine to your screen x resolution.
#define S3L_RESOLUTION_X 640 ///< Redefine to screen x resolution.
#endif
#ifndef S3L_RESOLUTION_Y
#define S3L_RESOLUTION_Y 480 ///< Redefine to your screen y resolution.
#define S3L_RESOLUTION_Y 480 ///< Redefine to screen y resolution.
#endif
/** Units of measurement in 3D space. There is S3L_FRACTIONS_PER_UNIT in one
spatial unit. By dividing the unit into fractions we effectively achieve a
fixed point arithmetic. The number of fractions is a constant that serves as
1.0 in floating point arithmetic (normalization etc.). */
typedef int32_t S3L_Unit;
/** How many fractions a spatial unit is split into. This is NOT SUPPOSED TO
BE REDEFINED, so rather don't do it (otherwise things may overflow etc.). */
#define S3L_FRACTIONS_PER_UNIT 512
typedef int16_t S3L_ScreenCoord;
typedef uint16_t S3L_Index;
#ifndef S3L_STRICT_NEAR_CULLING
#define S3L_STRICT_NEAR_CULLING 1 /**< If on, any triangle that only partially
intersects the near plane will be culled.
This can prevent errorneous rendering and
artifacts, but also makes triangles close to
the camera disappear. */
/** If on, any triangle that only partially intersects the near plane will be
culled. This can prevent errorneous rendering and artifacts, but also makes
triangles close to the camera disappear. */
#define S3L_STRICT_NEAR_CULLING 1
#endif
#ifndef S3L_FLAT
#define S3L_FLAT 0 /**< If on, disables computation of per-pixel
values such as barycentric coordinates and
depth -- these will still be available but
will be the same for the whole triangle. This
can be used to create flat-shaded renders and
will be a lot faster. With this option on you
will probably want to use sorting instead of
z-buffer. */
/** If on, disables computation of per-pixel values such as barycentric
coordinates and depth -- these will still be available but will be the same
for the whole triangle. This can be used to create flat-shaded renders and
will be a lot faster. With this option on you will probably want to use
sorting instead of z-buffer. */
#define S3L_FLAT 0
#endif
#if S3L_FLAT
@ -159,15 +173,13 @@
#endif
#ifndef S3L_PERSPECTIVE_CORRECTION
#define S3L_PERSPECTIVE_CORRECTION 0 /**< Specifies what type of perspective
correction (PC) to use. Remember this is an expensive
operation! Possible values:
/** Specifies what type of perspective correction (PC) to use. Remember this
is an expensive operation! Possible values:
- 0 No perspective correction. Fastest, ugly.
- 1 Per-pixel perspective correction, nice but very
expensive.
- 2 Partial perspecive correction by subdividing
triangles. */
- 0: No perspective correction. Fastest, ugly.
- 1: Per-pixel perspective correction, nice but very expensive.*/
#define S3L_PERSPECTIVE_CORRECTION 0
#endif
#if S3L_PERSPECTIVE_CORRECTION
@ -175,86 +187,68 @@
#endif
#ifndef S3L_COMPUTE_DEPTH
#define S3L_COMPUTE_DEPTH 1 /**< Whether to compute depth for each pixel
(fragment). Some other options may turn this
on. */
/** Whether to compute depth for each pixel (fragment). Some other options
may turn this on automatically. */
#define S3L_COMPUTE_DEPTH 1
#endif
typedef int32_t S3L_Unit; /**< Units of measurement in 3D space. There is
S3L_FRACTIONS_PER_UNIT in one spatial unit.
By dividing the unit into fractions we
effectively achieve fixed point arithmetic.
The number of fractions is a constant that
serves as 1.0 in floating point arithmetic
(normalization etc.). */
#define S3L_FRACTIONS_PER_UNIT 512 /**< How many fractions a spatial unit is
split into. WARNING: if setting higher than
1024, you'll probably have to modify a sin
table otherwise it will overflow. Also other
things may overflow, so rather don't do
it. */
typedef int16_t S3L_ScreenCoord;
typedef uint16_t S3L_Index;
#ifndef S3L_Z_BUFFER
#define S3L_Z_BUFFER 0 /**< What type of z-buffer (depth buffer) to use
for visibility determination. possible values:
/** What type of z-buffer (depth buffer) to use for visibility determination.
Possible values:
- 0 Don't use z-buffer. This saves a lot of memory, but
visibility checking won't be pixel-accurate and has
to mostly be done by other means (typically
sorting).
- 1 Use full z-buffer (of S3L_Units) for visibiltiy
determination. This is the most accurate option
(and also a fast one), but requires a big amount
of memory.
- 2 Use reduced-size z-buffer (of bytes). This is fast
and somewhat accurate, but inaccuracies can occur
and a considerable amount of memory is needed. */
- 0: Don't use z-buffer. This saves a lot of memory, but visibility checking
won't be pixel-accurate and has to mostly be done by other means
(typically sorting).
- 1: Use full z-buffer (of S3L_Units) for visibiltiy determination. This is
the most accurate option (and also a fast one), but requires a big
amount of memory.
- 2: Use reduced-size z-buffer (of bytes). This is fast and somewhat
accurate, but inaccuracies can occur and a considerable amount of memory
is needed. */
#define S3L_Z_BUFFER 0
#endif
#ifndef S3L_STENCIL_BUFFER
#define S3L_STENCIL_BUFFER 0 /**< Whether to use stencil buffer for drawing --
with this pixels that have already been
rasterized will be discarded. This is mostly
for front-to-back sorted drawing. */
/** Whether to use stencil buffer for drawing -- with this a pixel that would
be resterized over an already rasterized pixel will be discarded. This is
mostly for front-to-back sorted drawing. */
#define S3L_STENCIL_BUFFER 0
#endif
#ifndef S3L_SORT
#define S3L_SORT 0 /**< Defines how to sort triangles before
drawing a frame. This can be used to solve visibility
in case z-buffer is not used, to prevent overwrting
already rasterized pixels, implement transparency etc.
Note that for simplicity and performance a relatively
simple sorting is used which doesn't work completely
correctly, so mistakes can occur (even the best sorting
wouldn't be able to solve e.g. intersecting triangles).
Possible values:
/** Defines how to sort triangles before drawing a frame. This can be used to
solve visibility in case z-buffer is not used, to prevent overwrting already
rasterized pixels, implement transparency etc. Note that for simplicity and
performance a relatively simple sorting is used which doesn't work completely
correctly, so mistakes can occur (even the best sorting wouldn't be able to
solve e.g. intersecting triangles). Possible values:
- 0 Don't sort triangles. This is fastest.
- 1 Sort triangles from back to front. This can in most
cases solve visibility without requiring almost any
extra memory compared to z-buffer.
- 2 Sort triangles from front to back. This can be
faster than back to front, because we prevent
computing pixels that will be overwritten by nearer
ones, but we need a 1b stencil buffer for this
(enable S3L_STENCIL_BUFFER), so a bit more memory
is needed. */
- 0: Don't sort triangles. This is fastest.
- 1: Sort triangles from back to front. This can in most cases solve
visibility without requiring almost any extra memory compared to
z-buffer.
- 2: Sort triangles from front to back. This can be faster than back to
front, because we prevent computing pixels that will be overwritten by
nearer ones, but we need a 1b stencil buffer for this (enable
S3L_STENCIL_BUFFER), so a bit more memory is needed. */
#define S3L_SORT 0
#endif
#ifndef S3L_MAX_TRIANGES_DRAWN
#define S3L_MAX_TRIANGES_DRAWN 128 /**< Maximum number of triangles that can be
drawn in sorted modes. This affects the size
of a cache used for triangle sorting. */
/** Maximum number of triangles that can be drawn in sorted modes. This
affects the size of the cache used for triangle sorting. */
#define S3L_MAX_TRIANGES_DRAWN 128
#endif
#ifndef S3L_NEAR
#define S3L_NEAR (S3L_FRACTIONS_PER_UNIT / 4) /**< Distance of the near
clipping plane. Points in front or EXATLY ON
this plane are considered outside the
frustum. This must be >= 0. */
/** Distance of the near clipping plane. Points in front or EXATLY ON this
plane are considered outside the frustum. This must be >= 0. */
#define S3L_NEAR (S3L_FRACTIONS_PER_UNIT / 4)
#endif
#if S3L_NEAR <= 0
@ -262,17 +256,14 @@ typedef uint16_t S3L_Index;
#endif
#ifndef S3L_FAST_LERP_QUALITY
#define S3L_FAST_LERP_QUALITY 8 /**< Quality (scaling) of SOME linear
interpolations. 0 will most likely be faster,
but artifacts can occur for bigger tris,
while higher values can fix this -- in
theory all higher values will have the same
speed (it is a shift value), but it mustn't
be too high to prevent overflow. */
#endif
/** Quality (scaling) of SOME (stepped) linear interpolations. 0 will most
likely be a tiny bit faster, but artifacts can occur for bigger tris, while
higher values can fix this -- in theory all higher values will have the same
speed (it is a shift value), but it mustn't be too high to prevent
overflow. */
#define S3L_HALF_RESOLUTION_X (S3L_RESOLUTION_X >> 1)
#define S3L_HALF_RESOLUTION_Y (S3L_RESOLUTION_Y >> 1)
#define S3L_FAST_LERP_QUALITY 8
#endif
/** Vector that consists of four scalars and can represent homogenous
coordinates, but is generally also used as Vec3 and Vec2. */
@ -289,7 +280,7 @@ static inline void S3L_initVec4(S3L_Vec4 *v);
static inline void S3L_vec3Add(S3L_Vec4 *result, S3L_Vec4 added);
static inline void S3L_vec3Sub(S3L_Vec4 *result, S3L_Vec4 substracted);
#define S3L_writeVec4(v)\
#define S3L_logVec4(v)\
printf("Vec4: %d %d %d %d\n",((v).x),((v).y),((v).z),((v).w))
typedef struct
@ -302,7 +293,7 @@ typedef struct
S3L_Vec4 scale;
} S3L_Transform3D;
#define S3L_writeTransform3D(t)\
#define S3L_logTransform3D(t)\
printf("Transform3D: T = [%d %d %d], R = [%d %d %d], S = [%d %d %d]\n",\
(t).translation.x,(t).translation.y,(t).translation.z,\
(t).rotation.x,(t).rotation.y,(t).rotation.z,\
@ -331,10 +322,12 @@ void S3L_rotationToDirections(
S3L_Vec4 *right,
S3L_Vec4 *up);
typedef S3L_Unit S3L_Mat4[4][4]; /**< 4x4 matrix, used mostly for 3D
transforms. The indexing is this:
/** 4x4 matrix, used mostly for 3D transforms. The indexing is this:
matrix[column][row]. */
#define S3L_writeMat4(m)\
typedef S3L_Unit S3L_Mat4[4][4];
#define S3L_logMat4(m)\
printf("Mat4:\n %d %d %d %d\n %d %d %d %d\n %d %d %d %d\n %d %d %d %d\n"\
,(m)[0][0],(m)[1][0],(m)[2][0],(m)[3][0],\
(m)[0][1],(m)[1][1],(m)[2][1],(m)[3][1],\
@ -576,6 +569,9 @@ static inline void S3L_rotate2DPoint(S3L_Unit *x, S3L_Unit *y, S3L_Unit angle);
//=============================================================================
// privates
#define S3L_HALF_RESOLUTION_X (S3L_RESOLUTION_X >> 1)
#define S3L_HALF_RESOLUTION_Y (S3L_RESOLUTION_Y >> 1)
#define S3L_PROJECTION_PLANE_HEIGHT\
((S3L_RESOLUTION_Y * S3L_FRACTIONS_PER_UNIT * 2) / S3L_RESOLUTION_X)

2
testSDL.c
View file

@ -322,7 +322,7 @@ void draw()
printf("FPS: %d\n",fps);
printf("camera: ");
S3L_writeTransform3D(scene.camera.transform);
S3L_logTransform3D(scene.camera.transform);
fps = 0;
}
}