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Changed triangle membership test and somehow e5 works. TODO: Colors a…
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…re wrong and e1,e2 give segfault
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@Salil03
Salil03 committed Jan 25, 2024
1 parent d3df0ed commit 31365b6
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4 changes: 2 additions & 2 deletions a1/examples/e2.cpp
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@@ -1,7 +1,7 @@
#include "../src/a1.hpp"

// namespace R = COL781::Software;
namespace R = COL781::Hardware;
namespace R = COL781::Software;
// namespace R = COL781::Hardware;
using namespace glm;

int main() {
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4 changes: 2 additions & 2 deletions a1/examples/e3.cpp
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@@ -1,7 +1,7 @@
#include "../src/a1.hpp"
#include <glm/gtc/matrix_transform.hpp>
namespace R = COL781::Software;
// namespace R = COL781::Hardware;
// namespace R = COL781::Software;
namespace R = COL781::Hardware;
using namespace glm;

int main()
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156 changes: 82 additions & 74 deletions a1/src/sw.cpp
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Expand Up @@ -96,7 +96,6 @@ namespace Software
}
}


void expand(std::vector<int> &dims, std::vector<glm::vec4> &values, int index)
{
if (dims.size() < index + 1)
Expand Down Expand Up @@ -304,20 +303,18 @@ namespace Software

bool inTriangle(glm::vec2 &sample, glm::vec2 (&triangle)[3])
{
for (int k = 0; k < 3; k++)
{
glm::vec2 v1 = triangle[k % 3];
glm::vec2 v2 = triangle[(k + 1) % 3];
glm::vec2 s = v2 - v1;
glm::vec2 t(-s.y, s.x);

float dot = glm::dot(t, sample - v1);
if (dot < 0)
{
return false;
}
}
return true;
// idk why other methods didn't work. But this one works and seems to be faster
float denominator =
(triangle[0].x * (triangle[1].y - triangle[2].y) + triangle[0].y * (triangle[2].x - triangle[1].x) +
triangle[1].x * triangle[2].y - triangle[1].y * triangle[2].x);
float t1 = (sample.x * (triangle[2].y - triangle[0].y) + sample.y * (triangle[0].x - triangle[2].x) -
triangle[0].x * triangle[2].y + triangle[0].y * triangle[2].x) /
denominator;
float t2 = -(sample.x * (triangle[1].y - triangle[0].y) + sample.y * (triangle[0].x - triangle[1].x) -
triangle[0].x * triangle[1].y + triangle[0].y * triangle[1].x) /
denominator;
float s = t1 + t2;
return 0 <= t1 && t1 <= 1 && 0 <= t2 && t2 <= 1 && s <= 1;
}

float dperp(glm::vec2 p, glm::vec2 p1, glm::vec2 p2)
Expand All @@ -336,30 +333,28 @@ namespace Software
(Uint8)(color[3] * 255));
}

glm::vec3 flatten(glm::vec4 hom) {
return hom.xyz()/hom.w;
glm::vec3 flatten(glm::vec4 hom)
{
return hom.xyz() / hom.w;
}

glm::vec3 phi(glm::vec2 (&tri)[3], glm::vec2 pt) {
glm::vec3 phi(glm::vec2 (&tri)[3], glm::vec2 pt)
{
float norm = dperp(tri[0], tri[1], tri[2]);
return glm::vec3(
dperp(pt, tri[1], tri[2]) / dperp(tri[0], tri[1], tri[2]),
dperp(pt, tri[2], tri[0]) / dperp(tri[1], tri[2], tri[0]),
dperp(pt, tri[0], tri[1]) / dperp(tri[2], tri[0], tri[1])
);
return glm::vec3(dperp(pt, tri[1], tri[2]) / dperp(tri[0], tri[1], tri[2]),
dperp(pt, tri[2], tri[0]) / dperp(tri[1], tri[2], tri[0]),
dperp(pt, tri[0], tri[1]) / dperp(tri[2], tri[0], tri[1]));
}

glm::vec3 phi_pc(glm::vec4 (&hom_tri)[3], glm::vec3 p, glm::vec2 pt) {
float norm = (p[0]/hom_tri[0].w + p[1]/hom_tri[1].w + p[2]/hom_tri[2].w);
return glm::vec3(
p[0] / hom_tri[0].w,
p[1] / hom_tri[1].w,
p[2] / hom_tri[2].w
);
glm::vec3 phi_pc(glm::vec4 (&hom_tri)[3], glm::vec3 p, glm::vec2 pt)
{
float norm = (p[0] / hom_tri[0].w + p[1] / hom_tri[1].w + p[2] / hom_tri[2].w);
return glm::vec3(p[0] / hom_tri[0].w, p[1] / hom_tri[1].w, p[2] / hom_tri[2].w);
}

glm::vec4 interpolate(glm::vec4 (&vert_attribs)[3], glm::vec3 wts) {
return wts[0]*vert_attribs[0] + wts[1]*vert_attribs[1] + wts[2]*vert_attribs[2];
glm::vec4 interpolate(glm::vec4 (&vert_attribs)[3], glm::vec3 wts)
{
return wts[0] * vert_attribs[0] + wts[1] * vert_attribs[1] + wts[2] * vert_attribs[2];
}

////////////////////////////////////////////////////////////////////////////
Expand All @@ -370,20 +365,25 @@ namespace Software
{
depth_enabled = true;
z_buffer = new float[framebuffer->w * framebuffer->h];
for (int i=0; i<framebuffer->w; i++) {
for (int j=0; j<framebuffer->h; j++) {
z_buffer[framebuffer->h*i + j] = 1000000;
for (int i = 0; i < framebuffer->w; i++)
{
for (int j = 0; j < framebuffer->h; j++)
{
z_buffer[framebuffer->h * i + j] = 1000000;
}
}
}

void Rasterizer::clear(glm::vec4 color)
{
SDL_FillRect(framebuffer, NULL, vec4_to_color(framebuffer->format, color));
if (depth_enabled) {
for (int i=0; i<framebuffer->w; i++) {
for (int j=0; j<framebuffer->h; j++) {
z_buffer[framebuffer->h*i + j] = 1000000;
if (depth_enabled)
{
for (int i = 0; i < framebuffer->w; i++)
{
for (int j = 0; j < framebuffer->h; j++)
{
z_buffer[framebuffer->h * i + j] = 1000000;
}
}
}
Expand All @@ -410,54 +410,57 @@ namespace Software
int dim = object.attributeDims[i];
vertex_in_attrs[v].set<glm::vec4>(i, getAttribs(object, i, v, dim));
}
vertex_pos[v] = shader_program->vs(
shader_program->uniforms, vertex_in_attrs[v], vertex_out_attrs[v]
);
vertex_pos[v] = shader_program->vs(shader_program->uniforms, vertex_in_attrs[v], vertex_out_attrs[v]);
}

auto render_triangle = [&](glm::ivec3 idxs) {
glm::vec4 hom_tri[3] = {
vertex_pos[idxs[0]],
vertex_pos[idxs[1]],
vertex_pos[idxs[2]]
};
glm::vec2 tri[3] = {
flatten(hom_tri[0]).xy(),
flatten(hom_tri[1]).xy(),
flatten(hom_tri[2]).xy()
};

std::vector<std::tuple<int,int,glm::vec2>> fragments;
glm::vec4 hom_tri[3] = {vertex_pos[idxs[0]], vertex_pos[idxs[1]], vertex_pos[idxs[2]]};
glm::vec2 tri[3] = {flatten(hom_tri[0]).xy(), flatten(hom_tri[1]).xy(), flatten(hom_tri[2]).xy()};
// std::cout << tri[1].x << " " << tri[1].y << "\n";
// std::cout << tri[2].x << " " << tri[2].y << "\n";
// std::cout << tri[0].x << " " << tri[0].y << "\n";

std::vector<std::tuple<int, int, glm::vec2>> fragments;

// TODO make this scanline
for (int x = 0; x < w; x++)
{
for (int y = 0; y < h; y++)
{
glm::vec2 pt = sampleToPt(x, y, w, h);
if (inTriangle(pt, tri)) fragments.push_back({x, y, pt});
// glm::vec3 p = phi(tri, pt);
// if (0 <= p[0] && p[0] <= 1 && 0 <= p[1] && p[1] <= 1 && 0 <= p[2] && p[2] <= 1)
if (inTriangle(pt, tri))
{
// std::cout << "yes\n";
fragments.push_back({x, y, pt});
}
}
}

for (auto [x, y, pt] : fragments) {
for (auto [x, y, pt] : fragments)
{
glm::vec3 p = phi(tri, pt);
glm::vec3 p_pc = phi_pc(hom_tri, p, pt);
// nope.
// @salil have a look pls thx
float z = hom_tri[0].w*p_pc[0]/hom_tri[0].z + hom_tri[1].w*p_pc[1]/hom_tri[1].z + hom_tri[2].w*p_pc[2]/hom_tri[2].z;
float z = hom_tri[0].w * p_pc[0] / hom_tri[0].z + hom_tri[1].w * p_pc[1] / hom_tri[1].z +
hom_tri[2].w * p_pc[2] / hom_tri[2].z;
// std::cout << z << std::endl;

// glm::vec3 pos_ws = interpolate(hom_tri, p_pc);
// p_pc[2] = 1/z
if (z > z_buffer[(h-y-1)*w + x]) {
if (z > z_buffer[(h - y - 1) * w + x])
{
continue; // discard fragment
}
z_buffer[(h-y-1)*w + x] = p_pc[2];
z_buffer[(h - y - 1) * w + x] = p_pc[2];
// load and interpolate attributes
Attribs interp_attrs;
// HACK: find a way to iterate over the attributes present in
// HACK: find a way to iterate over the attributes present in
// out_attrs, instead of just guessing.
for (int i=0; i<object.attributeValues.size()-1; i++) {
for (int i = 0; i < object.attributeValues.size() - 1; i++)
{
glm::vec4 vert_attribs[3] = {
vertex_out_attrs[idxs[0]].get<glm::vec4>(i),
vertex_out_attrs[idxs[1]].get<glm::vec4>(i),
Expand All @@ -467,10 +470,10 @@ namespace Software
}

glm::vec4 color = shader_program->fs(shader_program->uniforms, interp_attrs);
pixels[(h-y-1)*w + x] = vec4_to_color(format, color);
pixels[(h - y - 1) * w + x] = vec4_to_color(format, color);
}
};

// render_triangle(object.indices[1]);
for (glm::ivec3 idxs : object.indices)
{
render_triangle(idxs);
Expand All @@ -483,25 +486,30 @@ namespace Software
{
auto windowSurface = SDL_GetWindowSurface(window);
int w = framebuffer->w;
int b = w/windowSurface->w;
int b = w / windowSurface->w;
int buf, avg[3];
Uint8 px[3];
for (int i=0; i<windowSurface->h; i++) {
for (int j=0; j<windowSurface->w; j++) {
for (int i = 0; i < windowSurface->h; i++)
{
for (int j = 0; j < windowSurface->w; j++)
{
avg[0] = avg[1] = avg[2] = 0;
for (int k=0; k<b; k++) {
for (int l=0; l<b; l++) {
buf = ((Uint32*)framebuffer->pixels)[w*(i*b + k) + j*b + l];
SDL_GetRGB(buf, framebuffer->format, px, (px+1), (px+2));
for (int k = 0; k < b; k++)
{
for (int l = 0; l < b; l++)
{
buf = ((Uint32 *)framebuffer->pixels)[w * (i * b + k) + j * b + l];
SDL_GetRGB(buf, framebuffer->format, px, (px + 1), (px + 2));
avg[0] += px[0];
avg[1] += px[1];
avg[2] += px[2];
}
}
avg[0] /= b*b;
avg[1] /= b*b;
avg[2] /= b*b;
((Uint32*)windowSurface->pixels)[windowSurface->w*i + j] = SDL_MapRGB(windowSurface->format, avg[0], avg[1], avg[2]);
avg[0] /= b * b;
avg[1] /= b * b;
avg[2] /= b * b;
((Uint32 *)windowSurface->pixels)[windowSurface->w * i + j] =
SDL_MapRGB(windowSurface->format, avg[0], avg[1], avg[2]);
}
}
// SDL_BlitScaled(framebuffer, NULL, windowSurface, NULL);
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