wiring stuff up using bres.! yay!

demos/demo1-wireframes/src/wirescene.cpp

@@ -32,23 +32,32 @@ void WireScene::load() {
     cube->add(VectorFx::fromInt(1, 1, -1));
     cube->add(VectorFx::fromInt(1, -1, 1));
     cube->add(VectorFx::fromInt(1, -1, -1));
-    /*
-     * should be translated, with camera 0,0,10, and with GBA dimensions, to:
-        SoftEngine.js:50 drawing 163,123
-        SoftEngine.js:50 drawing 155,115
-        SoftEngine.js:50 drawing 155,44
-        SoftEngine.js:50 drawing 84,44
-        SoftEngine.js:50 drawing 76,123
-        SoftEngine.js:50 drawing 84,115
-        SoftEngine.js:50 drawing 163,36
-        SoftEngine.js:50 drawing 76,36
-     */
-    //cube->rotateTo(int2fx(13), int2fx(13));
+
+    cube->addFace({ 0, 1, 2});
+    cube->addFace({ 1, 2, 3});
+    cube->addFace({ 1, 3, 6});
+    cube->addFace({ 1, 5, 6});
+    cube->addFace({ 0, 1, 4});
+    cube->addFace({ 1, 4, 5});
+
+    cube->addFace({ 2, 3, 7});
+    cube->addFace({ 3, 6, 7});
+    cube->addFace({ 0, 2, 7});
+    cube->addFace({ 0, 4, 7});
+    cube->addFace({ 4, 5, 6});
+    cube->addFace({ 4, 6, 7});
 }
 
 void WireScene::tick(u16 keys) {
     cube->rotate(2, 2);
-    if(keys & KEY_START || keys & KEY_A) {
+
+    if(keys & KEY_A) {
         cube->resetRotation();
+    } else if(keys & KEY_B) {
+        if(cube->isWired()) {
+            cube->unwire();
+        } else {
+            cube->wire();
+        }
     }
 }

engine/include/libgba-sprite-engine/gba_engine.h

@@ -9,6 +9,7 @@
 #include <libgba-sprite-engine/gba/tonc_memmap.h>
 #include <libgba-sprite-engine/gba/tonc_memmap.h>
 #include <libgba-sprite-engine/vectorfx.h>
+#include <libgba-sprite-engine/vectorpx.h>
 #include <libgba-sprite-engine/matrixfx.h>
 #include "scene.h"
 #include "sound_control.h"
@@ -50,8 +51,7 @@ private:
 
     void render();
     void renderClear();
-    inline void plotPixel(int x, int y, u8 clrId);
-    inline VectorFx project(const VectorFx &coord, const MatrixFx &transMat);
+    inline VectorPx project(const VectorFx &coord, const MatrixFx &transMat);
     void flipPage();
 
 public:
@@ -70,9 +70,12 @@ public:
 
     u16 readKeys();
     void update();
-    void delay(int times) {
+    inline void delay(int times) {
         for(int i = 0; i < times; i++){}
     }
+
+    inline void plotPixel(const VectorPx &pixel, u8 clrId);
+    inline void plotLine(const VectorPx &point0, const VectorPx &point1, u8 clrId);
 };
 
 

engine/include/libgba-sprite-engine/mesh.h

@@ -9,23 +9,41 @@
 #include <vector>
 #include <memory>
 
+typedef struct {
+    int a;
+    int b;
+    int c;
+} Face;
+
 class Mesh {
 private:
     VectorFx pos;
     VectorFx rot;
+    u8 cIndex;
+    bool wired;
 
     std::vector<std::unique_ptr<VectorFx>> verticesArr;
+    std::vector<Face> facesArr;
 
 public:
 
     void add(VectorFx v);
+    void addFace(Face f);
     inline std::vector<std::unique_ptr<VectorFx>> const& vertices() const {
         return verticesArr;
     }
 
+    inline std::vector<Face> const& faces() const {
+        return facesArr;
+    }
+
     inline VectorFx &position() { return pos; }
     inline VectorFx &rotation() { return rot; }
 
+    inline void wire() { wired = true; }
+    inline void unwire() { wired = false; }
+    inline bool isWired() const { return wired; }
+    inline u8 colorIndex() const { return cIndex; }
     inline FIXED rotx() const { return rot.x(); }
     inline FIXED roty() const { return rot.y(); }
     inline FIXED rotz() const { return rot.z(); }
@@ -43,7 +61,7 @@ public:
         rot.setY(rot.y() + y);
     }
 
-    explicit Mesh() : pos(VectorFx()), rot(VectorFx()) {}
+    explicit Mesh() : pos(VectorFx()), rot(VectorFx()), cIndex(1), wired(true) {}
     Mesh(const Mesh&) = delete;
     Mesh& operator=(const Mesh&) = delete;
 };

engine/include/libgba-sprite-engine/vectorpx.h

@@ -0,0 +1,23 @@
+//
+// Created by Wouter Groeneveld on 10/07/20.
+//
+
+#ifndef GBA_BITMAP_ENGINE_PROJECT_VECTOR2_H
+#define GBA_BITMAP_ENGINE_PROJECT_VECTOR2_H
+
+// a 2D vector with pixel-based ints
+
+class VectorPx {
+private:
+    int v_x, v_y;
+
+public:
+    VectorPx(int theX, int theY) : v_x(theX), v_y(theY) {}
+
+    static inline VectorPx fromFx(FIXED x, FIXED y) { return VectorPx(fx2int(x), fx2int(y)); }
+
+    inline int x() const { return v_x; }
+    inline int y() const { return v_y; }
+};
+
+#endif //GBA_BITMAP_ENGINE_PROJECT_VECTOR2_H

engine/src/gba_engine.cpp

@@ -8,6 +8,7 @@
 #include <libgba-sprite-engine/gba/tonc_core.h>
 #include <libgba-sprite-engine/matrixfx.h>
 #include <libgba-sprite-engine/background/text_stream.h>
+#include <libgba-sprite-engine/mesh.h>
 
 std::unique_ptr<SoundControl> GBAEngine::activeChannelA;
 std::unique_ptr<SoundControl> GBAEngine::activeChannelB;
@@ -147,23 +148,46 @@ void GBAEngine::flipPage() {
 
 // http://www.coranac.com/tonc/text/bitmaps.htm
 // this thing is supposed to be very slow. see link above.
-inline void GBAEngine::plotPixel(int x, int y, u8 clrId) {
-    u16 *dst = &vid_page[(y * M4_WIDTH + x) / 2];
-    if(x & 1) {
+inline void GBAEngine::plotPixel(const VectorPx &pixel, u8 clrId) {
+    u16 *dst = &vid_page[(pixel.y() * M4_WIDTH + pixel.x()) / 2];
+    if(pixel.x() & 1) {
         *dst = (*dst & 0xFF) | (clrId << 8);
     } else {
         *dst = (*dst & ~0xFF) | clrId;
     }
 }
 
-int i = 0;
+// more or less 1-to-1:
+// https://www.davrous.com/2013/06/14/tutorial-part-2-learning-how-to-write-a-3d-soft-engine-from-scratch-in-c-ts-or-js-drawing-lines-triangles/
+inline void GBAEngine::plotLine(const VectorPx &point0, const VectorPx &point1, u8 clrId) {
+    int x0 = point0.x();
+    int y0 = point0.y();
+    int x1 = point1.x();
+    int y1 = point1.y();
 
-inline VectorFx GBAEngine::project(const VectorFx &coord, const MatrixFx &transMat) {
+    int dx = ABS(x1 - x0);
+    int dy = ABS(y1 - y0);
+    int sx = (x0 < x1) ? 1 : -1;
+    int sy = (y0 < y1) ? 1 : -1;
+    int err = dx - dy;
+
+    while (true) {
+        plotPixel(VectorPx(x0, y0), clrId);
+
+        if ((x0 == x1) && (y0 == y1)) break;
+        auto e2 = 2 * err;
+        if (e2 > -dy) { err -= dy; x0 += sx; }
+        if (e2 < dx) { err += dx; y0 += sy; }
+    }
+}
+
+
+inline VectorPx GBAEngine::project(const VectorFx &coord, const MatrixFx &transMat) {
     auto point = MatrixFx::transformCoordinates(coord, transMat);
 
     auto x = fxmul(point.x(), GBA_SCREEN_WIDTH_FX) + fxdiv(GBA_SCREEN_WIDTH_FX, TWO);
     auto y = fxmul(-point.y(), GBA_SCREEN_HEIGHT_FX) + fxdiv(GBA_SCREEN_HEIGHT_FX, TWO);
-    return VectorFx(x, y, 0);
+    return VectorPx::fromFx(x, y);
 }
 
 // does the mesh rendering - to write mem before flipping
@@ -174,11 +198,27 @@ void GBAEngine::render() {
         auto worldMatrix = MatrixFx::rotationYawPitchRoll(mesh->roty(), mesh->rotx(), mesh->rotz()) * MatrixFx::translation(mesh->position());
         auto transformMatrix = worldMatrix * viewMatrix * projectionMatrix;
 
-        TextStream::instance().setText("rot: " + mesh->rotation().to_stringfl(), 1, 1);
+        if(mesh->isWired()) {
+            // triangular faces wireframes
+            for(auto& face : mesh->faces()) {
+                auto& vertexA = mesh->vertices()[face.a];
+                auto& vertexB = mesh->vertices()[face.b];
+                auto& vertexC = mesh->vertices()[face.c];
+
+                auto pixelA = project(*vertexA.get(), transformMatrix);
+                auto pixelB = project(*vertexB.get(), transformMatrix);
+                auto pixelC = project(*vertexC.get(), transformMatrix);
 
-        for(auto& vertex : mesh->vertices()) {
-            auto projectedPoint = project(*vertex.get(), transformMatrix).toInt();
-            plotPixel(projectedPoint.x(), projectedPoint.y(), 1);
+                plotLine(pixelA, pixelB, mesh->colorIndex());
+                plotLine(pixelB, pixelC, mesh->colorIndex());
+                plotLine(pixelC, pixelA, mesh->colorIndex());
+            }
+        } else {
+            // pixel-only
+            for (auto &vertex : mesh->vertices()) {
+                auto projectedPoint = project(*vertex.get(), transformMatrix);
+                plotPixel(projectedPoint, mesh->colorIndex());
+            }
         }
     }
 }

engine/src/mesh.cpp

@@ -10,3 +10,6 @@ void Mesh::add(VectorFx v) {
     verticesArr.push_back(std::unique_ptr<VectorFx>(new VectorFx(v)));
 }
 
+void Mesh::addFace(Face f) {
+    facesArr.push_back(f);
+}