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Added orthographic mode #6

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Added orthographic mode #6

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73251ff
Update gl.h
tobleroneaddict Feb 23, 2026
5c0a4eb
Update gl.cpp
tobleroneaddict Feb 23, 2026
a3deb29
Update gl.cpp
tobleroneaddict Feb 23, 2026
bc4fa90
Update gl.cpp
tobleroneaddict Feb 23, 2026
210fabb
Update gl.cpp
tobleroneaddict Feb 23, 2026
96d0d6b
Update gl.h
tobleroneaddict Feb 23, 2026
f0a1c96
Update gl.cpp
tobleroneaddict Feb 23, 2026
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23 changes: 18 additions & 5 deletions gl.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ static SDL_Surface *scr;
#define P(m, y, x) (m->data[y][x])

MATRIX *transformation;
static GLProjectionMode projection_mode = GLProjectionMode::GL_PROJECTION_PERSPECTIVE; //Default mode is perspective
static COLOR color;
static GLFix u, v;
static COLOR *screen;
Expand All @@ -27,8 +28,10 @@ static const TEXTURE *texture;
static unsigned int vertices_count = 0;
static VERTEX vertices[4];
static GLDrawMode draw_mode = GL_TRIANGLES;
static bool is_monochrome;
static COLOR *screen_inverted; //For monochrome calcs
#ifdef _TINSPIRE
static bool is_monochrome;
static COLOR *screen_inverted; //For monochrome calcs
#endif
#ifdef FPS_COUNTER
volatile unsigned int fps;
#endif
Expand Down Expand Up @@ -74,10 +77,9 @@ void nglUninit()
uninit_fastmath();
delete[] transformation;
delete[] z_buffer;

delete[] screen_inverted;


#ifdef _TINSPIRE
delete[] screen_inverted;
lcd_init(SCR_TYPE_INVALID);
#else
//TODO
Expand Down Expand Up @@ -133,8 +135,16 @@ void nglMultMatVectRes(const MATRIX *mat1, const VECTOR3 *vect, VECTOR3 *res)
res->z = P(mat1, 2, 0)*x + P(mat1, 2, 1)*y + P(mat1, 2, 2)*z + P(mat1, 2, 3);
}

void nglSetProjectionMode(GLProjectionMode mode)
{
projection_mode = mode;
}

void nglPerspective(VERTEX *v)
{
if (projection_mode == GL_PROJECTION_ORTHOGRAPHIC)
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@Vogtinator Vogtinator Feb 23, 2026

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I wonder if this is the right place. Arguably the projection should only be applied to actual drawing, not when calling nglPerspective manually? Not sure about use cases.

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@tobleroneaddict tobleroneaddict Feb 23, 2026

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It felt less verbose than adding it to every usage of nglPerspective().

return; //Ortho mode
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@Vogtinator Vogtinator Feb 23, 2026

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Needs blank line after this


#ifdef BETTER_PERSPECTIVE
float new_z = v->z;
decltype(new_z) new_x = v->x, new_y = v->y;
Expand Down Expand Up @@ -188,6 +198,9 @@ void nglPerspective(VERTEX *v)

void nglPerspective(VECTOR3 *v)
{
if (projection_mode == GL_PROJECTION_ORTHOGRAPHIC)
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return; //Ortho mode

#ifdef BETTER_PERSPECTIVE
float new_z = v->z;
decltype(new_z) new_x = v->x, new_y = v->y;
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7 changes: 7 additions & 0 deletions gl.h
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Expand Up @@ -111,6 +111,12 @@ class MATRIX {
#define GL_COLOR_BUFFER_BIT 1<<0
#define GL_DEPTH_BUFFER_BIT 1<<1

enum GLProjectionMode
{
GL_PROJECTION_PERSPECTIVE,
GL_PROJECTION_ORTHOGRAPHIC
};

enum GLDrawMode
{
GL_TRIANGLES,
Expand Down Expand Up @@ -162,6 +168,7 @@ void nglDrawTriangleZClipped(const VERTEX *low, const VERTEX *middle, const VERT
void nglInterpolateVertexZ(const VERTEX *from, const VERTEX *to, VERTEX *res);
void nglDrawLine3D(const VERTEX *v1, const VERTEX *v2);

void nglSetProjectionMode(GLProjectionMode mode);
void nglPerspective(VERTEX *v);
void nglPerspective(VECTOR3 *v);
void nglMultMatVectRes(const MATRIX *mat1, const VERTEX *vect, VERTEX *res);
Expand Down