added functionality for textured flat-bottom/top triangles

src/main.c

@@ -7,6 +7,7 @@
 #include "vector.h"
 #include "light.h"
 #include "mesh.h"
+#include "texture.h"
 #include "triangle.h"
 #include "array.h"
 #include "matrix.h"
@@ -50,12 +51,16 @@ void setup(void){
     float znear = 0.1;
     float zfar = 100.0;
     proj_matrix = mat4_make_perspective(fov, aspect, znear, zfar);
-    
+   
+    // Load the hardcoded texture data from the static array
+    mesh_texture = (uint32_t*)REDBRICK_TEXTURE;
+    texture_width = 64;
+    texture_height = 64;
 
     // Loads the cube values in the mesh data structure
-    //load_cube_mesh_data();
+    load_cube_mesh_data();
     //load_obj_file_data("./assets/f22.obj");
-    load_obj_file_data("./assets/cube.obj");
+    //load_obj_file_data("./assets/cube.obj");
 }
 
 void process_input(void){
@@ -126,8 +131,8 @@ void update(void){
 
     // Change the mesh scale/rotation values per animation frame
     mesh.rotation.x += 0.01;
-    mesh.rotation.y += 0.01;
+    //mesh.rotation.y += 0.01;
-    mesh.rotation.z += 0.01;
+    //mesh.rotation.z += 0.01;
 
     //mesh.scale.x += 0.01;
     //mesh.scale.y += 0.01;
@@ -241,6 +246,11 @@ void update(void){
                 { projected_points[1].x, projected_points[1].y },
                 { projected_points[2].x, projected_points[2].y },
             },
+            .texcoords = {
+                { mesh_face.a_uv.u, mesh_face.a_uv.v },
+                { mesh_face.b_uv.u, mesh_face.b_uv.v },
+                { mesh_face.c_uv.u, mesh_face.c_uv.v }
+            },
             // every triangle has a colour (as does each face)
             .color = triangle_color,
             .avg_depth = avg_depth
@@ -282,12 +292,12 @@ void render(void){
 
         // Draw textured triangle
         if (render_method == RENDER_TEXTURED || render_method == RENDER_TEXTURED_WIRE) {
-            //draw_textured_triangle(
+            draw_textured_triangle(
-            //    triangle.points[0].x, triangle.points[0].y, // vertex A
+                triangle.points[0].x, triangle.points[0].y, triangle.texcoords[0].u, triangle.texcoords[0].v,  // vertex A
-            //    triangle.points[1].x, triangle.points[1].y, // vertex B
+                triangle.points[1].x, triangle.points[1].y, triangle.texcoords[1].u, triangle.texcoords[1].v,  // vertex B
-            //    triangle.points[2].x, triangle.points[2].y, // vertex C                                                        
+                triangle.points[2].x, triangle.points[2].y, triangle.texcoords[2].u, triangle.texcoords[2].v,   // vertex C
-            //    triangle.color
+                mesh_texture                                                      
-            //);
+            );
 
         }
 

src/matrix.h

@@ -2,8 +2,8 @@
 // Created by tristan on 12/4/25.
 //
 
-#ifndef INC_3DRENDERER_MATRIX_H
+#ifndef MATRIX_H
-#define INC_3DRENDERER_MATRIX_H
+#define MATRIX_H
 
 #include "vector.h"
 #include "math.h"
@@ -25,4 +25,4 @@ mat4_t mat4_make_perspective(float fov, float aspect, float znear, float zfar);
 
 mat4_t mat4_mul_mat4(mat4_t a, mat4_t b);
 vec4_t mat4_mul_vec4_project(mat4_t mat_proj, vec4_t v); 
-#endif //INC_3DRENDERER_MATRIX_H
+#endif 

src/mesh.c

@@ -23,26 +23,25 @@ vec3_t cube_vertices[N_CUBE_VERTICES] = {
     { .x = -1, .y = -1, .z =  1 }   // 8  
 };
 
-
 face_t cube_faces[N_CUBE_FACES] = {
     // front
-    { .a = 1, .b = 2, .c = 3, .color = 0xFFFFFFFF },
+    { .a = 1, .b = 2, .c = 3, .a_uv = { 0, 0 }, .b_uv = { 0, 1 }, .c_uv = { 1, 1 }, .color = 0xFFFFFFFF },
-    { .a = 1, .b = 3, .c = 4, .color = 0xFFFFFFFF},
+    { .a = 1, .b = 3, .c = 4, .a_uv = { 0, 0 }, .b_uv = { 1, 1 }, .c_uv = { 1, 0 }, .color = 0xFFFFFFFF },
     // right
-    { .a = 4, .b = 3, .c = 5, .color = 0xFFFFFFFF},
+    { .a = 4, .b = 3, .c = 5, .a_uv = { 0, 0 }, .b_uv = { 0, 1 }, .c_uv = { 1, 1 }, .color = 0xFFFFFFFF },
-    { .a = 4, .b = 5, .c = 6, .color = 0xFFFFFFFF },
+    { .a = 4, .b = 5, .c = 6, .a_uv = { 0, 0 }, .b_uv = { 1, 1 }, .c_uv = { 1, 0 }, .color = 0xFFFFFFFF },
     // back
-    { .a = 6, .b = 5, .c = 7, .color = 0xFFFFFFFF },
+    { .a = 6, .b = 5, .c = 7, .a_uv = { 0, 0 }, .b_uv = { 0, 1 }, .c_uv = { 1, 1 }, .color = 0xFFFFFFFF },
-    { .a = 6, .b = 7, .c = 8, .color = 0xFFFFFFFF },
+    { .a = 6, .b = 7, .c = 8, .a_uv = { 0, 0 }, .b_uv = { 1, 1 }, .c_uv = { 1, 0 }, .color = 0xFFFFFFFF },
     // left
-    { .a = 8, .b = 7, .c = 2, .color = 0xFFFFFFFF },
+    { .a = 8, .b = 7, .c = 2, .a_uv = { 0, 0 }, .b_uv = { 0, 1 }, .c_uv = { 1, 1 }, .color = 0xFFFFFFFF },
-    { .a = 8, .b = 2, .c = 1, .color = 0xFFFFFFFF },
+    { .a = 8, .b = 2, .c = 1, .a_uv = { 0, 0 }, .b_uv = { 1, 1 }, .c_uv = { 1, 0 }, .color = 0xFFFFFFFF },
     // top
-    { .a = 2, .b = 7, .c = 5, .color = 0xFFFFFFFF },
+    { .a = 2, .b = 7, .c = 5, .a_uv = { 0, 0 }, .b_uv = { 0, 1 }, .c_uv = { 1, 1 }, .color = 0xFFFFFFFF },
-    { .a = 2, .b = 5, .c = 3, .color = 0xFFFFFFFF },
+    { .a = 2, .b = 5, .c = 3, .a_uv = { 0, 0 }, .b_uv = { 1, 1 }, .c_uv = { 1, 0 }, .color = 0xFFFFFFFF },
     // bottom
-    { .a = 6, .b = 8, .c = 1, .color = 0xFFFFFFFF },
+    { .a = 6, .b = 8, .c = 1, .a_uv = { 0, 0 }, .b_uv = { 0, 1 }, .c_uv = { 1, 1 }, .color = 0xFFFFFFFF },
-    { .a = 6, .b = 1, .c = 4, .color = 0xFFFFFFFF }
+    { .a = 6, .b = 1, .c = 4, .a_uv = { 0, 0 }, .b_uv = { 1, 1 }, .c_uv = { 1, 0 }, .color = 0xFFFFFFFF }
 };
 
 void load_cube_mesh_data(void) {

src/swap.c

@@ -0,0 +1,13 @@
+#include "swap.h"
+
+void int_swap(int *a, int *b) {
+    int tmp = *a;
+    *a = *b;
+    *b = tmp;
+}
+
+void float_swap(float *a, float *b) {
+    float tmp = *a;
+    *a = *b;
+    *b = tmp;
+}

src/swap.h

@@ -0,0 +1,7 @@
+#ifndef SWAP_H
+#define SWAP_H
+
+void int_swap(int* a, int* b);
+void float_swap(float* a, float* b);
+
+#endif

src/texture.c

@@ -70,4 +70,4 @@ const uint8_t REDBRICK_TEXTURE[] = {
     0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x48, 0x48, 0x48, 0xff, 0x54, 0x54, 0x54, 0xff, 0x48, 0x48, 0x48, 0xff, 0x38, 0x38, 0x38, 0xff, 0x34, 0x34, 0x34, 0xff, 0x34, 0x34, 0x34, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x38, 0x38, 0x38, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x20, 0x20, 0x20, 0xff, 0x2c, 0x2c, 0x2c, 0xff, 0x2c, 0x2c, 0x2c, 0xff,
     0x38, 0x38, 0x38, 0xff, 0x54, 0x54, 0x54, 0xff, 0x38, 0x38, 0x38, 0xff, 0x54, 0x54, 0x54, 0xff, 0x38, 0x38, 0x38, 0xff, 0x38, 0x38, 0x38, 0xff, 0x38, 0x38, 0x38, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x38, 0x38, 0x38, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x54, 0x54, 0x54, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x54, 0x54, 0x54, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x38, 0x38, 0x38, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x40, 0x40, 0x40, 0xff, 0x38, 0x38, 0x38, 0xff, 0x38, 0x38, 0x38, 0xff, 0x40, 0x40, 0x40, 0xff, 0x38, 0x38, 0x38, 0xff, 0x38, 0x38, 0x38, 0xff, 0x40, 0x40, 0x40, 0xff, 0x48, 0x48, 0x48, 0xff, 0x40, 0x40, 0x40, 0xff, 0x38, 0x38, 0x38, 0xff, 0x40, 0x40, 0x40, 0xff, 0x54, 0x54, 0x54, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x38, 0x38, 0x38, 0xff, 0x54, 0x54, 0x54, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x40, 0x40, 0x40, 0xff, 0x38, 0x38, 0x38, 0xff, 0x40, 0x40, 0x40, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff, 0x48, 0x48, 0x48, 0xff,
     0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff, 0x54, 0x54, 0x54, 0xff,
-};
+};

src/texture.h

@@ -1,6 +1,7 @@
 #ifndef TEXTURE_H
 #define TEXTURE_H
 
+#include <stdio.h>
 #include <stdint.h>
 
 typedef struct {
@@ -13,4 +14,4 @@ extern int texture_height;
 extern uint32_t* mesh_texture;
 extern const uint8_t REDBRICK_TEXTURE[];
 
-#endif
+#endif

src/triangle.c

@@ -1,11 +1,6 @@
 #include "triangle.h"
 #include "display.h"
-
+#include "swap.h"
-void int_swap(int *a, int *b) {
-    int tmp = *a;
-    *a = *b;
-    *b = tmp;
-}
 
 // Draw a filled triangle with a flat bottom
 void fill_flat_bottom_triangle(int x0, int y0, int x1, int y1, int x2, int y2, uint32_t color) {
@@ -81,3 +76,109 @@ void draw_filled_triangle(int x0, int y0, int x1, int y1, int x2, int y2, uint32
         fill_flat_top_triangle(x1, y1, Mx, My, x2, y2, color);
     }
 }
+
+////////////////////////////////////////////////////////////////////////////////
+// Draw a textured triangle with the flat-top/flat-bottom method
+// We split the original triangle in two, half flat-bottom and half flat-top
+////////////////////////////////////////////////////////////////////////////////
+//
+//         v0
+//         /\
+//        /  \
+//       /    \
+//      /      \
+//     v1-------v3
+//     \_        \
+//       \_       \
+//         \_      \
+//           \_     \
+//             \_    \
+//               \_   \
+//                 \_  \
+//                   \_ \
+//                      \\
+//                        \
+//                        v2
+////////////////////////////////////////////////////////////////////////////////
+// TODO: use color_t type or uint32_t type?
+void draw_textured_triangle(
+    int x0, int y0, float u0, float v0,
+    int x1, int y1, float u1, float v1,
+    int x2, int y2, float u2, float v2,
+    color_t* texture
+) {
+    // We need to sort the vertices by y-coordinate asecnding (y0 < y1 < y2)
+    if (y0 > y1) {
+        int_swap(&y0, &y1);
+        int_swap(&x0, &x1);
+        float_swap(&u0, &u1);
+        float_swap(&v0, &v1);
+    }
+
+    if (y1 > y2) {
+        int_swap(&y1, &y2);
+        int_swap(&x1, &x2);
+        float_swap(&u1, &u2);
+        float_swap(&v1, &v2);
+    }
+
+    if (y0 > y1) {
+        int_swap(&y0, &y1);
+        int_swap(&x0, &x1);
+        float_swap(&u0, &u1);
+        float_swap(&v0, &v1);
+    }
+
+    //////////////////////////////////////////////////////
+    // Render the upper part of the triangle (flat-bottom)
+    //////////////////////////////////////////////////////
+    float inv_slope_1 = 0;
+    float inv_slope_2 = 0;
+
+    // first and second slope of triangle legs
+    if (y1 - y0 != 0) inv_slope_1 = (float)(x1 - x0) / abs(y1 - y0);
+    if (y2 - y0 != 0) inv_slope_2 = (float)(x2 - x0) / abs(y2 - y0);
+
+    if (y1 - y0 != 0) {
+        for (int y = y0; y <= y1; y++) {
+            int x_start = x1 + (y - y1) * inv_slope_1;
+            int x_end = x0 + (y - y0) * inv_slope_2;
+
+            if (x_end < x_start) {
+                int_swap(&x_start, &x_end); // swap if x_start is to the right of x_end
+            }
+
+            for (int x = x_start; x < x_end; x++) {
+                // Draw our pixel with the color that comes from the texture
+                draw_pixel(x, y, 0xFFFF00FF);
+            }
+        }
+    }
+
+
+    //////////////////////////////////////////////////////
+    // Render the upper part of the triangle (flat-bottom)
+    //////////////////////////////////////////////////////
+    inv_slope_1 = 0;
+    inv_slope_2 = 0;
+
+    // first and second slope of triangle legs
+    if (y2 - y1 != 0) inv_slope_1 = (float)(x2 - x1) / abs(y2 - y1);
+    if (y2 - y0 != 0) inv_slope_2 = (float)(x2 - x0) / abs(y2 - y0);
+
+    if (y2 - y1 != 0) {
+        for (int y = y1; y <= y2; y++) {
+            int x_start = x1 + (y - y1) * inv_slope_1;
+            int x_end = x0 + (y - y0) * inv_slope_2;
+
+            if (x_end < x_start) {
+                int_swap(&x_start, &x_end); // swap if x_start is to the right of x_end
+            }
+
+            for (int x = x_start; x < x_end; x++) {
+                // Draw our pixel with the color that comes from the texture
+                draw_pixel(x, y, 0xFFFF00FF);
+            }
+        }
+    }     
+}

src/triangle.h

@@ -25,6 +25,12 @@ typedef struct {
 
 void draw_filled_triangle(int x0, int y0, int x1, int y1, int x2, int y2, uint32_t color);
 void draw_triangle(int x0, int y0, int x1, int y1, int x2, int y2, uint32_t color);
+void draw_textured_triangle(
+        int x0, int y0, float u0, float v0,
+        int x1, int y1, float u1, float v1,
+        int x2, int y2, float u2, float v2,
+        color_t* texture 
+        );
 
 // TODO: void draw_textured_triangle(...);