ref: 008dd8584d1af5944190b6f67aa98883114243ce
parent: 75d8d14bd96170dd3395a2e1329ba2dd2b920e6e
author: David <gek@katherine>
date: Mon Feb 15 11:31:20 EST 2021
Love for TinyGL
--- a/README.md
+++ b/README.md
@@ -101,6 +101,64 @@
Plot pixel directly to the buffer.
+## TOGGLEABLE FEATURES
+
+See `include/zfeatures.h`
+
+Standard OpenGL features that you can disable for extra performance or smaller binary size.
+```c
+#define TGL_FEATURE_ARRAYS 1
+#define TGL_FEATURE_DISPLAYLISTS 1
+#define TGL_FEATURE_POLYGON_OFFSET 1
+#define TGL_FEATURE_POLYGON_STIPPLE 1
+```
+
+Change the dimensions of a polygon stipple pattern, and how it's interpreted.
+
+If you're only ever going to use very small stipple patterns, it's recommended you alter these settings.
+```c
+//A stipple pattern is 128 bytes in size.
+#define TGL_POLYGON_STIPPLE_BYTES 128
+//A stipple pattern is 2^5 (32) bits wide.
+#define TGL_POLYGON_STIPPLE_POW2_WIDTH 5
+//The stipple pattern mask (the last bits of the screen coordinates used for indexing)
+//The default pattern is 32 bits wide and 32 bits tall, or 4 bytes per row and 32 tall, 4 * 32 = 128 bytes.
+#define TGL_POLYGON_STIPPLE_MASK_X 31
+#define TGL_POLYGON_STIPPLE_MASK_Y 31
+```
+
+These features enable you to achieve the effect of `discard` in GLSL shaders.
+
+You can use this to draw objects which only ever need discard-type alpha transparency.
+
+Simply specify a color to use for that purpose. My favorite choice is hideous magenta (0xff00ff)
+
+The color mask is "and'd" with the color before the test, in case you wanted to only test one color (red, for instance)
+
+Note that when changing between bit depths, you will need to alter the NO_COPY_COLOR and NO_DRAW_COLOR if you use those
+features.
+```c
+#define TGL_FEATURE_NO_COPY_COLOR 0
+#define TGL_FEATURE_NO_DRAW_COLOR 0
+#define TGL_FEATURE_FORCE_CLEAR_NO_COPY_COLOR 0
+#define TGL_NO_COPY_COLOR 0xff00ff
+#define TGL_NO_DRAW_COLOR 0xff00ff
+//^ solid debug pink.
+#define TGL_COLOR_MASK 0x00ffffff
+```
+
+Alter the bit depth of rendering. Note that all textures loaded are assumed to be R8G8B8 (in that order, with no Alpha or padding)
+
+Textures are converted internally (see image_util.c) to the renderer's output format.
+
+at the current time, only 16 and 32 bit rendering are maintained and tested regularly.
+```c
+#define TGL_FEATURE_8_BITS 0
+#define TGL_FEATURE_24_BITS 0
+//These are the only maintained modes.
+#define TGL_FEATURE_16_BITS 0
+#define TGL_FEATURE_32_BITS 1
+```
## FIXED BUGS FROM THE ORIGINAL!
binary files a/SDL_Examples/texture.png b/SDL_Examples/texture.png differ
--- a/include/zbuffer.h
+++ b/include/zbuffer.h
@@ -54,9 +54,11 @@
#else
-#error wrong TGL_FEATURE_RENDER_BITS buddy
+#error "wrong TGL_FEATURE_RENDER_BITS buddy"
#endif
+
+
typedef struct {int xsize,ysize;
--- a/include/zfeatures.h
+++ b/include/zfeatures.h
@@ -7,7 +7,6 @@
#define TGL_FEATURE_ARRAYS 1
#define TGL_FEATURE_DISPLAYLISTS 1
#define TGL_FEATURE_POLYGON_OFFSET 1
-
#define TGL_FEATURE_POLYGON_STIPPLE 1
//A stipple pattern is 128 bytes in size.
#define TGL_POLYGON_STIPPLE_BYTES 128
@@ -14,18 +13,19 @@
//A stipple pattern is 2^5 (32) bits wide.
#define TGL_POLYGON_STIPPLE_POW2_WIDTH 5
//The stipple pattern mask (the last bits of the screen coordinates used for indexing)
-//The default pattern is 32 bits wide and 32 bits tall, or 4 bytes per row and 32 tall, 4 * 32 128 bytes.
+//The default pattern is 32 bits wide and 32 bits tall, or 4 bytes per row and 32 tall, 4 * 32 = 128 bytes.
#define TGL_POLYGON_STIPPLE_MASK_X 31
#define TGL_POLYGON_STIPPLE_MASK_Y 31
//These are features useful for integrating TinyGL with other renderers.
#define TGL_FEATURE_NO_COPY_COLOR 0
+#define TGL_FEATURE_NO_DRAW_COLOR 0
#define TGL_FEATURE_FORCE_CLEAR_NO_COPY_COLOR 0
#define TGL_NO_COPY_COLOR 0xff00ff
-//NOTE: fc02fc is what you'll get if you set glColor3f to 1,0,1.
+#define TGL_NO_DRAW_COLOR 0xff00ff
//^ solid debug pink.
-#define TGL_COLOR_MASK 0xffffffff
-//^ mask to check for copybuffer. This is configured for the default mode.
+#define TGL_COLOR_MASK 0x00ffffff
+//^ mask to check for while drawing/copying.
/*
* Matrix of internal and external pixel formats supported. 'Y' means
--- a/src/msghandling.c
+++ b/src/msghandling.c
@@ -1,7 +1,7 @@
#include <stdarg.h>
#include <stdio.h>
#include "../include/GL/gl.h"
-#define NDEBUG
+//#define NDEBUG
#ifdef NDEBUG
#define NO_DEBUG_OUTPUT
--- a/src/zline.c
+++ b/src/zline.c
@@ -8,18 +8,27 @@
GLushort *pz;
PIXEL *pp;
GLint zz;
-
+ #if TGL_FEATURE_NO_DRAW_COLOR == 1
+ PIXEL col;
+ #endif
pz = zb->zbuf + (p->y * zb->xsize + p->x);
pp = (PIXEL *) ((GLbyte *) zb->pbuf + zb->linesize * p->y + p->x * PSZB);
zz = p->z >> ZB_POINT_Z_FRAC_BITS;
if (ZCMP(zz, *pz)) {-#if TGL_FEATURE_RENDER_BITS == 24
- pp[0]=p->r>>8;
- pp[1]=p->g>>8;
- pp[2]=p->b>>8;
+//#if TGL_FEATURE_RENDER_BITS == 24
+ //pp[0]=p->r>>8;
+ //pp[1]=p->g>>8;
+ //pp[2]=p->b>>8;
+//#else
+#if TGL_FEATURE_NO_DRAW_COLOR == 1
+#define NODRAWTEST(color) ( (color & TGL_COLOR_MASK) != TGL_NO_DRAW_COLOR)
+ col = RGB_TO_PIXEL(p->r, p->g, p->b);
+ if(NODRAWTEST(col))
+ *pp = RGB_TO_PIXEL(p->r, p->g, p->b);
#else
- *pp = RGB_TO_PIXEL(p->r, p->g, p->b);
+ *pp = RGB_TO_PIXEL(p->r, p->g, p->b);
#endif
+//#endif
*pz = zz;
}
}
--- a/src/ztriangle.c
+++ b/src/ztriangle.c
@@ -1,4 +1,5 @@
#include <stdlib.h>
+#include "msghandling.h"
#include "../include/zbuffer.h"
@@ -5,14 +6,9 @@
#if TGL_FEATURE_RENDER_BITS == 32
-
-
#elif TGL_FEATURE_RENDER_BITS == 16
-
#else
-
-#error "USE 32 BIT MODE!!!"
-
+#error "WRONG MODE!!!"
#endif
@@ -25,15 +21,22 @@
//NOTES Divide by 8 to get the byte Get the actual bit
#define STIPBIT(_a) (zb->stipplepattern[(XSTIP(_a) | (YSTIP<<TGL_POLYGON_STIPPLE_POW2_WIDTH))>>3] & (1<<(XSTIP(_a) & 7)))
#define STIPTEST(_a) !(zb->dostipple && !STIPBIT(_a))
-#define ZCMP(z,zpix,_a) ((z) >= (zpix) && STIPTEST(_a))
+
#else
-#define ZCMP(z,zpix,_a) ((z) >= (zpix))
+#define STIPTEST(_a) (1)
+//#define ZCMP(z,zpix,_a) ((z) >= (zpix))
#endif
+#if TGL_FEATURE_NO_DRAW_COLOR == 1
+#define NODRAWTEST(c) ( (c & TGL_COLOR_MASK) != TGL_NO_DRAW_COLOR)
+#else
+#define NODRAWTEST(c) (1)
+#endif
+#define ZCMP(z,zpix,_a,c) ((z) >= (zpix) && STIPTEST(_a) && NODRAWTEST(c))
void ZB_fillTriangleFlat(ZBuffer *zb,
ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
@@ -56,7 +59,7 @@
#define PUT_PIXEL(_a) \
{ \zz=z >> ZB_POINT_Z_FRAC_BITS; \
- if (ZCMP(zz,pz[_a],_a)) { \+ if (ZCMP(zz,pz[_a],_a,color)) { \pp[_a]=color; \
pz[_a]=zz; \
} \
@@ -75,8 +78,8 @@
void ZB_fillTriangleSmooth(ZBuffer *zb,
ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
{-#if TGL_FEATURE_RENDER_BITS == 16
-// GLint _drgbdx;
+#if TGL_FEATURE_NO_DRAW_COLOR == 1
+ PIXEL c;
#endif
//GLuint color;
#define INTERP_Z
@@ -91,33 +94,39 @@
\
}
-#define PUT_PIXEL(_a) \
-{ \- zz=z >> ZB_POINT_Z_FRAC_BITS; \
- if (ZCMP(zz,pz[_a],_a)) { \- pp[_a] = RGB_TO_PIXEL(or1, og1, ob1);\
- pz[_a]=zz; \
- }\
- z+=dzdx; \
- og1+=dgdx; \
- or1+=drdx; \
- ob1+=dbdx; \
+#if TGL_FEATURE_NO_DRAW_COLOR != 1
+#define PUT_PIXEL(_a) \
+{ \+ zz=z >> ZB_POINT_Z_FRAC_BITS; \
+ if (ZCMP(zz,pz[_a],_a,RGB_TO_PIXEL(or1, og1, ob1))) { \+ pp[_a] = RGB_TO_PIXEL(or1, og1, ob1); \
+ pz[_a]=zz; \
+ } \
+ z+=dzdx; \
+ og1+=dgdx; \
+ or1+=drdx; \
+ ob1+=dbdx; \
}
-
+#else
+#define PUT_PIXEL(_a) \
+{ \+ zz=z >> ZB_POINT_Z_FRAC_BITS; \
+ c = RGB_TO_PIXEL(or1, og1, ob1); \
+ if (ZCMP(zz,pz[_a],_a,c)) { \+ pp[_a] = c; \
+ pz[_a]=zz; \
+ } \
+ z+=dzdx; \
+ og1+=dgdx; \
+ or1+=drdx; \
+ ob1+=dbdx; \
+}
+#endif
//END OF 32 bit mode
#elif TGL_FEATURE_RENDER_BITS == 16
-/*
-#define DRAW_INIT() \
-{ \-_drgbdx=(SAR_RND_TO_ZERO(drdx, 6) << 22) & 0xFFC00000; \
-_drgbdx|=SAR_RND_TO_ZERO(dgdx,5) & 0x000007FF; \
-_drgbdx|=(SAR_RND_TO_ZERO(dbdx,7) << 12) & 0x001FF000; \
-}
-*/
-
#define DRAW_INIT() \
{ \\
@@ -124,20 +133,8 @@
}
-/*#define PUT_PIXEL(_a) \
-{ \- zz=z >> ZB_POINT_Z_FRAC_BITS; \
- if (ZCMP(zz,pz[_a],_a)) { \- tmp=rgb&0xF81F07E0; \
- pp[_a] = tmp | (tmp >> 16);\
- pz[_a]=zz; \
- }\
- z+=dzdx; \
- rgb=(rgb+drgbdx) & ( ~ 0x00200800);\
-}
-*/
-
+/*
#define PUT_PIXEL(_a) \
{ \zz=z >> ZB_POINT_Z_FRAC_BITS; \
@@ -150,44 +147,54 @@
or1+=drdx; \
ob1+=dbdx; \
}
-/*
-#define DRAW_LINE() \
-{ \- register GLushort *pz; \
- register PIXEL *pp; \
- register GLuint tmp,z,zz,rgb,drgbdx; \
- register GLint n; \
- n=(x2 >> 16) - x1; \
- pp=pp1+x1; \
- pz=pz1+x1; \
- z=z1; \
- rgb=(r1 << 16) & 0xFFC00000; \
- rgb|=(g1 >> 5) & 0x000007FF; \
- rgb|=(b1 << 5) & 0x001FF000; \
- drgbdx=_drgbdx; \
- while (n>=3) { \- PUT_PIXEL(0); \
- PUT_PIXEL(1); \
- PUT_PIXEL(2); \
- PUT_PIXEL(3); \
- pz+=4; \
- pp+=4; \
- n-=4; \
- } \
- while (n>=0) { \- PUT_PIXEL(0); \
- pz+=1; \
- pp+=1; \
- n-=1; \
- } \
+*/
+
+#if TGL_FEATURE_NO_DRAW_COLOR != 1
+#define PUT_PIXEL(_a) \
+{ \+ zz=z >> ZB_POINT_Z_FRAC_BITS; \
+ if (ZCMP(zz,pz[_a],_a,0)) { \+ pp[_a] = RGB_TO_PIXEL(or1, og1, ob1); \
+ pz[_a]=zz; \
+ } \
+ z+=dzdx; \
+ og1+=dgdx; \
+ or1+=drdx; \
+ ob1+=dbdx; \
}
+#else
+#define PUT_PIXEL(_a) \
+{ \+ zz=z >> ZB_POINT_Z_FRAC_BITS; \
+ c = RGB_TO_PIXEL(or1, og1, ob1); \
+ if (ZCMP(zz,pz[_a],_a,c)) { \+ pp[_a] = c; \
+ pz[_a]=zz; \
+ } \
+ z+=dzdx; \
+ og1+=dgdx; \
+ or1+=drdx; \
+ ob1+=dbdx; \
+}
+#endif
-*/
#endif
//^ End of 16 bit mode stuff
#include "ztriangle.h"
} //EOF smooth fill triangle
+
+//
+//
+// TEXTURE MAPPED TRIANGLES
+// Section_Header
+//
+//
+//
+//
+
+
+
void ZB_setTexture(ZBuffer *zb,PIXEL *texture)
{zb->current_texture=texture;
@@ -198,6 +205,9 @@
{PIXEL *texture;
+#if TGL_FEATURE_NO_DRAW_COLOR == 1
+ PIXEL c;
+#endif
#define INTERP_Z
#define INTERP_ST
@@ -207,11 +217,11 @@
}
-
+#if TGL_FEATURE_NO_DRAW_COLOR != 1
#define PUT_PIXEL(_a) \
{ \zz=z >> ZB_POINT_Z_FRAC_BITS; \
- if (ZCMP(zz,pz[_a],_a)) { \+ if (ZCMP(zz,pz[_a],_a,0)) { \pp[_a]=texture[((t & 0x3FC00000) | s) >> 14]; \
pz[_a]=zz; \
} \
@@ -219,7 +229,20 @@
s+=dsdx; \
t+=dtdx; \
}
-
+#else
+#define PUT_PIXEL(_a) \
+{ \+ zz=z >> ZB_POINT_Z_FRAC_BITS; \
+ c = texture[((t & 0x3FC00000) | s) >> 14];\
+ if (ZCMP(zz,pz[_a],_a,c)) { \+ pp[_a]=c; \
+ pz[_a]=zz; \
+ } \
+ z+=dzdx; \
+ s+=dsdx; \
+ t+=dtdx; \
+}
+#endif
#include "ztriangle.h"
}
@@ -237,7 +260,9 @@
{PIXEL *texture;
GLfloat fdzdx,fndzdx,ndszdx,ndtzdx;
-
+#if TGL_FEATURE_NO_DRAW_COLOR == 1
+ PIXEL c;
+#endif
#define INTERP_Z
#define INTERP_STZ
@@ -252,11 +277,11 @@
ndtzdx=NB_INTERP * dtzdx;\
}
-
+#if TGL_FEATURE_NO_DRAW_COLOR != 1
#define PUT_PIXEL(_a) \
{ \zz=z >> ZB_POINT_Z_FRAC_BITS; \
- if (ZCMP(zz,pz[_a],_a)) { \+ if (ZCMP(zz,pz[_a],_a,0)) { \pp[_a]=*(PIXEL *)((GLbyte *)texture+ \
(((t & 0x3FC00000) | (s & 0x003FC000)) >> (17 - PSZSH)));\
pz[_a]=zz; \
@@ -265,7 +290,21 @@
s+=dsdx; \
t+=dtdx; \
}
-
+#else
+#define PUT_PIXEL(_a) \
+{ \+ zz=z >> ZB_POINT_Z_FRAC_BITS; \
+ c= *(PIXEL *)((GLbyte *)texture+ \
+ (((t & 0x3FC00000) | (s & 0x003FC000)) >> (17 - PSZSH)));\
+ if (ZCMP(zz,pz[_a],_a,c)) { \+ pp[_a]=c; \
+ pz[_a]=zz; \
+ } \
+ z+=dzdx; \
+ s+=dsdx; \
+ t+=dtdx; \
+}
+#endif
#define DRAW_LINE() \