From 8d7316baad2886696264bd720037f05f00889d8a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Miloslav=20=C4=8C=C3=AD=C5=BE?= Date: Tue, 7 May 2019 20:23:11 +0200 Subject: [PATCH] Improve the cube --- s3l.h | 26 +++++++++- testSDL.c | 138 ++++++++++++++++++++++++++++++------------------------ 2 files changed, 102 insertions(+), 62 deletions(-) diff --git a/s3l.h b/s3l.h index 97f9b98..b47d995 100644 --- a/s3l.h +++ b/s3l.h @@ -1009,7 +1009,31 @@ static inline void S3L_mapCameraToScreen(S3L_Vec4 point, S3L_Camera *camera, // ^ S3L_FRACTIONS_PER_UNIT cancel out } -void S3L_drawModel( +/* + Helper function to interpolate texture coordinates based on barycentric + coordinates. +*/ + +void S3L_interpolateTexCoords( + S3L_Unit u0, + S3L_Unit v0, + S3L_Unit u1, + S3L_Unit v1, + S3L_Unit u2, + S3L_Unit v2, + S3L_PixelInfo *p, + S3L_Unit *u, + S3L_Unit *v + ) +{ + *u = (p->barycentric0 * u0 + p->barycentric1 * u1 + p->barycentric2 * u2) / + S3L_FRACTIONS_PER_UNIT; + + *v = (p->barycentric0 * v0 + p->barycentric1 * v1 + p->barycentric2 * v2) / + S3L_FRACTIONS_PER_UNIT; +} + +void S3L_drawModelIndexed( const S3L_Unit coords[], const S3L_Index triangleVertexIndices[], uint16_t triangleCount, diff --git a/testSDL.c b/testSDL.c index 03dc76e..7630702 100644 --- a/testSDL.c +++ b/testSDL.c @@ -14,6 +14,71 @@ #define SCREEN_WIDTH 640 #define SCREEN_HEIGHT 480 +const int16_t test_coords[] = + { + 100,100, 99,101, 101,101, // 0, small triangle + 190,50, 200,10, 400,80, // 1, arbitrary + 40,80, 60,50, 100,30, // 2, arbitrary + 350,270, 440,200, 490,220, // 3, arbitrary + 150,300, 290,400, 450,400, // 4, regular + 105,200, 120,200, 201,200, // 5, horizontal line + 300,200, 300,250, 300,220, // 6, vertical line + 496,15, 613,131, 552,203 + }; + +#define S S3L_FRACTIONS_PER_UNIT + +S3L_Unit ver[] = +{ + S/2, -S/2, -S/2, // 0 front, bottom, right + -S/2, -S/2, -S/2, // 1 front, bottom, left + S/2, S/2, -S/2, // 2 front, top, right + -S/2, S/2, -S/2, // 3 front, top, left + S/2, -S/2, S/2, // 4 back, bottom, right + -S/2, -S/2, S/2, // 5 back, bottom, left + S/2, S/2, S/2, // 6 back, top, right + -S/2, S/2, S/2 // 7 back, top, left +}; + +S3L_Unit tex_coords[] = +{ + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16, + 16,0, 0,0, 16,16 +}; + +#undef S + +const S3L_Index tri[] = +{ + 0, 3, 2, // front + 0, 1, 3, + + 4, 0, 2, // right + 4, 2, 6, + + 5, 4, 6, // back + 6, 7, 5, + + 7, 3, 1, // left + 7, 1, 5, + + 3, 6, 2, // top + 3, 7, 6, + + 4, 1, 0, // bottom + 4, 5, 1 +}; + const uint8_t testTexture[] = { 2,2,2,0,0,0,2,2,2,2,0,0,0,2,2,2, @@ -70,73 +135,24 @@ uint8_t texturePixel(int32_t u, int32_t v) void drawPixel(S3L_PixelInfo *p) { - float b0 = p->barycentric0 / ((float) S3L_FRACTIONS_PER_UNIT); - float b1 = p->barycentric1 / ((float) S3L_FRACTIONS_PER_UNIT); - float b2 = p->barycentric2 / ((float) S3L_FRACTIONS_PER_UNIT); + S3L_Unit u, v, *coords; - int32_t u = b0 * 0 + b1 * 0 + b2 * 16; - int32_t v = b0 * 0 + b1 * 16 + b2 * 16; + coords = tex_coords + p->triangleID * 6; + + S3L_interpolateTexCoords( + coords[0],coords[1], + coords[2],coords[3], + coords[4],coords[5], + p, + &u,&v); uint8_t col = texturePixel(u,v); setPixel(p->x,p->y,col * 120,20,(2 - col) * 120); -/* - setPixel(p->x,p->y, - p->barycentric0 / ((float) S3L_FRACTIONS_PER_UNIT) * 255, - p->barycentric1 / ((float) S3L_FRACTIONS_PER_UNIT) * 255, - p->barycentric2 / ((float) S3L_FRACTIONS_PER_UNIT) * 255); -*/ + +// setPixel(p->x,p->y,p->barycentric0 / ((float) S3L_FRACTIONS_PER_UNIT) * 255,p->barycentric1 / ((float) S3L_FRACTIONS_PER_UNIT) * 255,p->barycentric2 / ((float) S3L_FRACTIONS_PER_UNIT) * 255); } -const int16_t test_coords[] = - { - 100,100, 99,101, 101,101, // 0, small triangle - 190,50, 200,10, 400,80, // 1, arbitrary - 40,80, 60,50, 100,30, // 2, arbitrary - 350,270, 440,200, 490,220, // 3, arbitrary - 150,300, 290,400, 450,400, // 4, regular - 105,200, 120,200, 201,200, // 5, horizontal line - 300,200, 300,250, 300,220, // 6, vertical line - 496,15, 613,131, 552,203 - }; - -#define S S3L_FRACTIONS_PER_UNIT - -S3L_Unit ver[] = -{ - S/2, -S/2, -S/2, // 0 front, bottom, right - -S/2, -S/2, -S/2, // 1 front, bottom, left - S/2, S/2, -S/2, // 2 front, top, right - -S/2, S/2, -S/2, // 3 front, top, left - S/2, -S/2, S/2, // 4 back, bottom, right - -S/2, -S/2, S/2, // 5 back, bottom, left - S/2, S/2, S/2, // 6 back, top, right - -S/2, S/2, S/2 // 7 back, top, left -}; - -#undef S - -const S3L_Index tri[] = -{ - 0, 3, 2, // front - 0, 1, 3, - - 4, 0, 2, // right - 4, 2, 6, - - 5, 4, 6, // back - 6, 7, 5, - - 7, 3, 1, // left - 7, 1, 5, - - 3, 6, 2, // top - 3, 7, 6, - - 4, 1, 0, // bottom - 4, 5, 1 -}; - S3L_Camera camera; S3L_Transform3D modelTransform; S3L_DrawConfig conf; @@ -148,7 +164,7 @@ void draw() // modelTransform.rotation.z = frame * 0.2; // modelTransform.rotation.x = frame * 0.1; - S3L_drawModel(ver,tri,12,modelTransform,camera,conf); + S3L_drawModelIndexed(ver,tri,12,modelTransform,camera,conf); /* conf.backfaceCulling = S3L_BACKFACE_CULLING_NONE;