ClassiCube/src/Graphics_SoftGPU.c
2024-07-29 19:09:58 +10:00

971 lines
27 KiB
C

#include "Core.h"
#if CC_GFX_BACKEND == CC_GFX_BACKEND_SOFTGPU
#include "_GraphicsBase.h"
#include "Errors.h"
#include "Window.h"
static cc_bool faceCulling;
static int fb_width, fb_height;
static struct Bitmap fb_bmp;
static float vp_hwidth, vp_hheight;
static int fb_maxX, fb_maxY;
static BitmapCol* colorBuffer;
static BitmapCol clearColor;
static cc_bool colWrite = true;
static int cb_stride;
static float* depthBuffer;
static cc_bool depthTest = true;
static cc_bool depthWrite = true;
static int db_stride;
static void* gfx_vertices;
static GfxResourceID white_square;
void Gfx_RestoreState(void) {
InitDefaultResources();
// 1x1 dummy white texture
struct Bitmap bmp;
BitmapCol pixels[1] = { BITMAPCOLOR_WHITE };
Bitmap_Init(bmp, 1, 1, pixels);
white_square = Gfx_CreateTexture(&bmp, 0, false);
}
void Gfx_FreeState(void) {
FreeDefaultResources();
Gfx_DeleteTexture(&white_square);
}
void Gfx_Create(void) {
Gfx.MaxTexWidth = 4096;
Gfx.MaxTexHeight = 4096;
Gfx.Created = true;
Gfx.BackendType = CC_GFX_BACKEND_SOFTGPU;
Gfx_RestoreState();
}
static void DestroyBuffers(void) {
Window_FreeFramebuffer(&fb_bmp);
Mem_Free(depthBuffer);
depthBuffer = NULL;
}
void Gfx_Free(void) {
Gfx_FreeState();
DestroyBuffers();
}
typedef struct CCTexture {
int width, height;
BitmapCol pixels[];
} CCTexture;
static CCTexture* curTexture;
static BitmapCol* curTexPixels;
static int curTexWidth, curTexHeight;
static int texWidthMask, texHeightMask;
void Gfx_BindTexture(GfxResourceID texId) {
if (!texId) texId = white_square;
CCTexture* tex = texId;
curTexture = tex;
curTexPixels = tex->pixels;
curTexWidth = tex->width;
curTexHeight = tex->height;
texWidthMask = (1 << Math_ilog2(tex->width)) - 1;
texHeightMask = (1 << Math_ilog2(tex->height)) - 1;
}
void Gfx_DeleteTexture(GfxResourceID* texId) {
GfxResourceID data = *texId;
if (data) Mem_Free(data);
*texId = NULL;
}
static GfxResourceID Gfx_AllocTexture(struct Bitmap* bmp, int rowWidth, cc_uint8 flags, cc_bool mipmaps) {
CCTexture* tex = (CCTexture*)Mem_Alloc(2 + bmp->width * bmp->height, 4, "Texture");
tex->width = bmp->width;
tex->height = bmp->height;
CopyTextureData(tex->pixels, bmp->width * BITMAPCOLOR_SIZE,
bmp, rowWidth * BITMAPCOLOR_SIZE);
return tex;
}
void Gfx_UpdateTexture(GfxResourceID texId, int x, int y, struct Bitmap* part, int rowWidth, cc_bool mipmaps) {
CCTexture* tex = (CCTexture*)texId;
BitmapCol* dst = (tex->pixels + x) + y * tex->width;
CopyTextureData(dst, tex->width * BITMAPCOLOR_SIZE,
part, rowWidth * BITMAPCOLOR_SIZE);
}
void Gfx_EnableMipmaps(void) { }
void Gfx_DisableMipmaps(void) { }
/*########################################################################################################################*
*------------------------------------------------------State management---------------------------------------------------*
*#########################################################################################################################*/
void Gfx_SetFog(cc_bool enabled) { }
void Gfx_SetFogCol(PackedCol col) { }
void Gfx_SetFogDensity(float value) { }
void Gfx_SetFogEnd(float value) { }
void Gfx_SetFogMode(FogFunc func) { }
void Gfx_SetFaceCulling(cc_bool enabled) {
faceCulling = enabled;
}
static void SetAlphaTest(cc_bool enabled) {
/* Uses value from Gfx_SetAlphaTest */
}
static void SetAlphaBlend(cc_bool enabled) {
/* Uses value from Gfx_SetAlphaBlending */
}
void Gfx_SetAlphaArgBlend(cc_bool enabled) { }
static void ClearColorBuffer(void) {
int i, x, y, size = fb_width * fb_height;
if (cb_stride == fb_width) {
for (i = 0; i < size; i++) colorBuffer[i] = clearColor;
} else {
/* Slower partial buffer clear */
for (y = 0; y < fb_height; y++) {
i = y * cb_stride;
for (x = 0; x < fb_width; x++) {
colorBuffer[i + x] = clearColor;
}
}
}
}
static void ClearDepthBuffer(void) {
int i, size = fb_width * fb_height;
for (i = 0; i < size; i++) depthBuffer[i] = 100000000.0f;
}
void Gfx_ClearBuffers(GfxBuffers buffers) {
if (buffers & GFX_BUFFER_COLOR) ClearColorBuffer();
if (buffers & GFX_BUFFER_DEPTH) ClearDepthBuffer();
}
void Gfx_ClearColor(PackedCol color) {
int R = PackedCol_R(color);
int G = PackedCol_G(color);
int B = PackedCol_B(color);
int A = PackedCol_A(color);
clearColor = BitmapCol_Make(R, G, B, A);
}
void Gfx_SetDepthTest(cc_bool enabled) {
depthTest = enabled;
}
void Gfx_SetDepthWrite(cc_bool enabled) {
depthWrite = enabled;
}
static void SetColorWrite(cc_bool r, cc_bool g, cc_bool b, cc_bool a) {
// TODO
}
void Gfx_DepthOnlyRendering(cc_bool depthOnly) {
colWrite = !depthOnly;
}
/*########################################################################################################################*
*-------------------------------------------------------Index buffers-----------------------------------------------------*
*#########################################################################################################################*/
GfxResourceID Gfx_CreateIb2(int count, Gfx_FillIBFunc fillFunc, void* obj) {
return (void*)1;
}
void Gfx_BindIb(GfxResourceID ib) { }
void Gfx_DeleteIb(GfxResourceID* ib) { }
/*########################################################################################################################*
*-------------------------------------------------------Vertex buffers----------------------------------------------------*
*#########################################################################################################################*/
static GfxResourceID Gfx_AllocStaticVb(VertexFormat fmt, int count) {
return Mem_TryAlloc(count, strideSizes[fmt]);
}
void Gfx_BindVb(GfxResourceID vb) { gfx_vertices = vb; }
void Gfx_DeleteVb(GfxResourceID* vb) {
GfxResourceID data = *vb;
if (data) Mem_Free(data);
*vb = 0;
}
void* Gfx_LockVb(GfxResourceID vb, VertexFormat fmt, int count) {
return vb;
}
void Gfx_UnlockVb(GfxResourceID vb) {
gfx_vertices = vb;
}
static GfxResourceID Gfx_AllocDynamicVb(VertexFormat fmt, int maxVertices) {
return Mem_TryAlloc(maxVertices, strideSizes[fmt]);
}
void Gfx_BindDynamicVb(GfxResourceID vb) { Gfx_BindVb(vb); }
void* Gfx_LockDynamicVb(GfxResourceID vb, VertexFormat fmt, int count) {
return vb;
}
void Gfx_UnlockDynamicVb(GfxResourceID vb) {
gfx_vertices = vb;
}
void Gfx_DeleteDynamicVb(GfxResourceID* vb) { Gfx_DeleteVb(vb); }
/*########################################################################################################################*
*---------------------------------------------------------Matrices--------------------------------------------------------*
*#########################################################################################################################*/
static float texOffsetX, texOffsetY;
static struct Matrix _view, _proj, _mvp;
void Gfx_LoadMatrix(MatrixType type, const struct Matrix* matrix) {
if (type == MATRIX_VIEW) _view = *matrix;
if (type == MATRIX_PROJ) _proj = *matrix;
Matrix_Mul(&_mvp, &_view, &_proj);
}
void Gfx_LoadMVP(const struct Matrix* view, const struct Matrix* proj, struct Matrix* mvp) {
_view = *view;
_proj = *proj;
Matrix_Mul(mvp, view, proj);
_mvp = *mvp;
}
void Gfx_EnableTextureOffset(float x, float y) {
texOffsetX = x;
texOffsetY = y;
}
void Gfx_DisableTextureOffset(void) {
texOffsetX = 0;
texOffsetY = 0;
}
void Gfx_CalcOrthoMatrix(struct Matrix* matrix, float width, float height, float zNear, float zFar) {
/* Source https://learn.microsoft.com/en-us/windows/win32/direct3d9/d3dxmatrixorthooffcenterrh */
/* The simplified calculation below uses: L = 0, R = width, T = 0, B = height */
/* NOTE: This calculation is shared with Direct3D 11 backend */
*matrix = Matrix_Identity;
matrix->row1.x = 2.0f / width;
matrix->row2.y = -2.0f / height;
matrix->row3.z = 1.0f / (zNear - zFar);
matrix->row4.x = -1.0f;
matrix->row4.y = 1.0f;
matrix->row4.z = zNear / (zNear - zFar);
}
static float Cotangent(float x) { return Math_CosF(x) / Math_SinF(x); }
void Gfx_CalcPerspectiveMatrix(struct Matrix* matrix, float fov, float aspect, float zFar) {
float zNear = 0.1f;
/* Source https://learn.microsoft.com/en-us/windows/win32/direct3d9/d3dxmatrixperspectivefovrh */
/* NOTE: This calculation is shared with Direct3D 11 backend */
float c = Cotangent(0.5f * fov);
*matrix = Matrix_Identity;
matrix->row1.x = c / aspect;
matrix->row2.y = c;
matrix->row3.z = zFar / (zNear - zFar);
matrix->row3.w = -1.0f;
matrix->row4.z = (zNear * zFar) / (zNear - zFar);
matrix->row4.w = 0.0f;
}
/*########################################################################################################################*
*---------------------------------------------------------Rendering-------------------------------------------------------*
*#########################################################################################################################*/
typedef struct Vector3 { float x, y, z; } Vector3;
typedef struct Vector2 { float x, y; } Vector2;
typedef struct Vertex_ {
float x, y, z, w;
float u, v;
PackedCol c;
} Vertex;
static void TransformVertex2D(int index, Vertex* vertex) {
// TODO: avoid the multiply, just add down in DrawTriangles
char* ptr = (char*)gfx_vertices + index * gfx_stride;
Vector3* pos = (Vector3*)ptr;
vertex->x = pos->x;
vertex->y = pos->y;
if (gfx_format != VERTEX_FORMAT_TEXTURED) {
struct VertexColoured* v = (struct VertexColoured*)ptr;
vertex->u = 0.0f;
vertex->v = 0.0f;
vertex->c = v->Col;
} else {
struct VertexTextured* v = (struct VertexTextured*)ptr;
vertex->u = v->U;
vertex->v = v->V;
vertex->c = v->Col;
}
}
static int TransformVertex3D(int index, Vertex* vertex) {
// TODO: avoid the multiply, just add down in DrawTriangles
char* ptr = (char*)gfx_vertices + index * gfx_stride;
Vector3* pos = (Vector3*)ptr;
vertex->x = pos->x * _mvp.row1.x + pos->y * _mvp.row2.x + pos->z * _mvp.row3.x + _mvp.row4.x;
vertex->y = pos->x * _mvp.row1.y + pos->y * _mvp.row2.y + pos->z * _mvp.row3.y + _mvp.row4.y;
vertex->z = pos->x * _mvp.row1.z + pos->y * _mvp.row2.z + pos->z * _mvp.row3.z + _mvp.row4.z;
vertex->w = pos->x * _mvp.row1.w + pos->y * _mvp.row2.w + pos->z * _mvp.row3.w + _mvp.row4.w;
if (gfx_format != VERTEX_FORMAT_TEXTURED) {
struct VertexColoured* v = (struct VertexColoured*)ptr;
vertex->u = 0.0f;
vertex->v = 0.0f;
vertex->c = v->Col;
} else {
struct VertexTextured* v = (struct VertexTextured*)ptr;
vertex->u = (v->U + texOffsetX);
vertex->v = (v->V + texOffsetY);
vertex->c = v->Col;
}
return vertex->z >= 0.0f;
}
static void ViewportVertex3D(Vertex* vertex) {
float invW = 1.0f / vertex->w;
vertex->x = vp_hwidth * (1 + vertex->x * invW);
vertex->y = vp_hheight * (1 - vertex->y * invW);
vertex->z = vertex->z * invW;
vertex->w = invW;
vertex->u *= invW;
vertex->v *= invW;
}
// Ensure it's inlined, whereas Math_FloorF might not be
static CC_INLINE int FastFloor(float value) {
int valueI = (int)value;
return valueI > value ? valueI - 1 : valueI;
}
#define edgeFunction(ax,ay, bx,by, cx,cy) (((bx) - (ax)) * ((cy) - (ay)) - ((by) - (ay)) * ((cx) - (ax)))
static void DrawTriangle2D(Vertex* V0, Vertex* V1, Vertex* V2) {
int x0 = (int)V0->x, y0 = (int)V0->y;
int x1 = (int)V1->x, y1 = (int)V1->y;
int x2 = (int)V2->x, y2 = (int)V2->y;
int minX = min(x0, min(x1, x2));
int minY = min(y0, min(y1, y2));
int maxX = max(x0, max(x1, x2));
int maxY = max(y0, max(y1, y2));
int area = edgeFunction(x0,y0, x1,y1, x2,y2);
// Reject triangles completely outside
if (maxX < 0 || minX > fb_maxX) return;
if (maxY < 0 || minY > fb_maxY) return;
// Perform scissoring
minX = max(minX, 0); maxX = min(maxX, fb_maxX);
minY = max(minY, 0); maxY = min(maxY, fb_maxY);
float factor = 1.0f / area;
float u0 = V0->u * curTexWidth, u1 = V1->u * curTexWidth, u2 = V2->u * curTexWidth;
float v0 = V0->v * curTexHeight, v1 = V1->v * curTexHeight, v2 = V2->v * curTexHeight;
PackedCol color = V0->c;
// https://fgiesen.wordpress.com/2013/02/10/optimizing-the-basic-rasterizer/
// Essentially these are the deltas of edge functions between X/Y and X/Y + 1 (i.e. one X/Y step)
int dx01 = y0 - y1, dy01 = x1 - x0;
int dx12 = y1 - y2, dy12 = x2 - x1;
int dx20 = y2 - y0, dy20 = x0 - x2;
float bc0_start = edgeFunction(x1,y1, x2,y2, minX+0.5f,minY+0.5f);
float bc1_start = edgeFunction(x2,y2, x0,y0, minX+0.5f,minY+0.5f);
float bc2_start = edgeFunction(x0,y0, x1,y1, minX+0.5f,minY+0.5f);
for (int y = minY; y <= maxY; y++, bc0_start += dy12, bc1_start += dy20, bc2_start += dy01)
{
float bc0 = bc0_start;
float bc1 = bc1_start;
float bc2 = bc2_start;
for (int x = minX; x <= maxX; x++, bc0 += dx12, bc1 += dx20, bc2 += dx01)
{
float ic0 = bc0 * factor;
float ic1 = bc1 * factor;
float ic2 = bc2 * factor;
if (ic0 < 0 || ic1 < 0 || ic2 < 0) continue;
int cb_index = y * cb_stride + x;
int R, G, B, A;
if (gfx_format == VERTEX_FORMAT_TEXTURED) {
float u = ic0 * u0 + ic1 * u1 + ic2 * u2;
float v = ic0 * v0 + ic1 * v1 + ic2 * v2;
int texX = ((int)u) & texWidthMask;
int texY = ((int)v) & texHeightMask;
int texIndex = texY * curTexWidth + texX;
BitmapCol tColor = curTexPixels[texIndex];
int a1 = PackedCol_A(color), a2 = BitmapCol_A(tColor);
A = ( a1 * a2 ) >> 8;
int r1 = PackedCol_R(color), r2 = BitmapCol_R(tColor);
R = ( r1 * r2 ) >> 8;
int g1 = PackedCol_G(color), g2 = BitmapCol_G(tColor);
G = ( g1 * g2 ) >> 8;
int b1 = PackedCol_B(color), b2 = BitmapCol_B(tColor);
B = ( b1 * b2 ) >> 8;
} else {
R = PackedCol_R(color);
G = PackedCol_G(color);
B = PackedCol_B(color);
A = PackedCol_A(color);
}
if (gfx_alphaTest && A < 0x80) continue;
if (gfx_alphaBlend) {
BitmapCol dst = colorBuffer[cb_index];
int dstR = BitmapCol_R(dst);
int dstG = BitmapCol_G(dst);
int dstB = BitmapCol_B(dst);
R = (R * A + dstR * (255 - A)) >> 8;
G = (G * A + dstG * (255 - A)) >> 8;
B = (B * A + dstB * (255 - A)) >> 8;
}
colorBuffer[cb_index] = BitmapCol_Make(R, G, B, 0xFF);
}
}
}
static void DrawTriangle3D(Vertex* V0, Vertex* V1, Vertex* V2) {
int x0 = (int)V0->x, y0 = (int)V0->y;
int x1 = (int)V1->x, y1 = (int)V1->y;
int x2 = (int)V2->x, y2 = (int)V2->y;
int minX = min(x0, min(x1, x2));
int minY = min(y0, min(y1, y2));
int maxX = max(x0, max(x1, x2));
int maxY = max(y0, max(y1, y2));
int area = edgeFunction(x0,y0, x1,y1, x2,y2);
if (faceCulling) {
// https://gamedev.stackexchange.com/questions/203694/how-to-make-backface-culling-work-correctly-in-both-orthographic-and-perspective
if (area < 0) return;
}
// Reject triangles completely outside
if (maxX < 0 || minX > fb_maxX) return;
if (maxY < 0 || minY > fb_maxY) return;
// Perform scissoring
minX = max(minX, 0); maxX = min(maxX, fb_maxX);
minY = max(minY, 0); maxY = min(maxY, fb_maxY);
// NOTE: W in frag variables below is actually 1/W
float factor = 1.0f / area;
float w0 = V0->w, w1 = V1->w, w2 = V2->w;
// TODO proper clipping
if (w0 <= 0 || w1 <= 0 || w2 <= 0) {
return;
}
float z0 = V0->z, z1 = V1->z, z2 = V2->z;
float u0 = V0->u, u1 = V1->u, u2 = V2->u;
float v0 = V0->v, v1 = V1->v, v2 = V2->v;
PackedCol color = V0->c;
// https://fgiesen.wordpress.com/2013/02/10/optimizing-the-basic-rasterizer/
// Essentially these are the deltas of edge functions between X/Y and X/Y + 1 (i.e. one X/Y step)
int dx01 = y0 - y1, dy01 = x1 - x0;
int dx12 = y1 - y2, dy12 = x2 - x1;
int dx20 = y2 - y0, dy20 = x0 - x2;
float bc0_start = edgeFunction(x1,y1, x2,y2, minX+0.5f,minY+0.5f);
float bc1_start = edgeFunction(x2,y2, x0,y0, minX+0.5f,minY+0.5f);
float bc2_start = edgeFunction(x0,y0, x1,y1, minX+0.5f,minY+0.5f);
for (int y = minY; y <= maxY; y++, bc0_start += dy12, bc1_start += dy20, bc2_start += dy01)
{
float bc0 = bc0_start;
float bc1 = bc1_start;
float bc2 = bc2_start;
for (int x = minX; x <= maxX; x++, bc0 += dx12, bc1 += dx20, bc2 += dx01)
{
float ic0 = bc0 * factor;
float ic1 = bc1 * factor;
float ic2 = bc2 * factor;
if (ic0 < 0 || ic1 < 0 || ic2 < 0) continue;
int db_index = y * db_stride + x;
float w = 1 / (ic0 * w0 + ic1 * w1 + ic2 * w2);
float z = (ic0 * z0 + ic1 * z1 + ic2 * z2) * w;
if (depthTest && (z < 0 || z > depthBuffer[db_index])) continue;
if (!colWrite) {
if (depthWrite) depthBuffer[db_index] = z;
continue;
}
int R, G, B, A;
if (gfx_format == VERTEX_FORMAT_TEXTURED) {
float u = (ic0 * u0 + ic1 * u1 + ic2 * u2) * w;
float v = (ic0 * v0 + ic1 * v1 + ic2 * v2) * w;
int texX = ((int)(Math_AbsF(u - FastFloor(u)) * curTexWidth )) & texWidthMask;
int texY = ((int)(Math_AbsF(v - FastFloor(v)) * curTexHeight)) & texHeightMask;
int texIndex = texY * curTexWidth + texX;
BitmapCol tColor = curTexPixels[texIndex];
int a1 = PackedCol_A(color), a2 = BitmapCol_A(tColor);
A = ( a1 * a2 ) >> 8;
int r1 = PackedCol_R(color), r2 = BitmapCol_R(tColor);
R = ( r1 * r2 ) >> 8;
int g1 = PackedCol_G(color), g2 = BitmapCol_G(tColor);
G = ( g1 * g2 ) >> 8;
int b1 = PackedCol_B(color), b2 = BitmapCol_B(tColor);
B = ( b1 * b2 ) >> 8;
} else {
R = PackedCol_R(color);
G = PackedCol_G(color);
B = PackedCol_B(color);
A = PackedCol_A(color);
}
if (gfx_alphaTest && A < 0x80) continue;
int cb_index = y * cb_stride + x;
if (gfx_alphaBlend) {
BitmapCol dst = colorBuffer[cb_index];
int dstR = BitmapCol_R(dst);
int dstG = BitmapCol_G(dst);
int dstB = BitmapCol_B(dst);
R = (R * A + dstR * (255 - A)) >> 8;
G = (G * A + dstG * (255 - A)) >> 8;
B = (B * A + dstB * (255 - A)) >> 8;
}
if (depthWrite) depthBuffer[db_index] = z;
colorBuffer[cb_index] = BitmapCol_Make(R, G, B, 0xFF);
}
}
}
#define V0_VIS (1 << 0)
#define V1_VIS (1 << 1)
#define V2_VIS (1 << 2)
#define V3_VIS (1 << 3)
// https://github.com/behindthepixels/EDXRaster/blob/master/EDXRaster/Core/Clipper.h
static void ClipLine(Vertex* v1, Vertex* v2, Vertex* V) {
float t = Math_AbsF(v1->z / (v2->z - v1->z));
float invt = 1.0f - t;
V->x = invt * v1->x + t * v2->x;
V->y = invt * v1->y + t * v2->y;
//V->z = invt * v1->z + t * v2->z;
V->z = 0.0f; // clipped against near plane anyways (I.e Z/W = 0 --> Z = 0)
V->w = invt * v1->w + t * v2->w;
V->u = invt * v1->u + t * v2->u;
V->v = invt * v1->v + t * v2->v;
V->c = v1->c;
}
// https://casual-effects.com/research/McGuire2011Clipping/clip.glsl
static void DrawClipped(int mask, Vertex* v0, Vertex* v1, Vertex* v2, Vertex* v3) {
Vertex tmp[2];
Vertex* a = &tmp[0];
Vertex* b = &tmp[1];
switch (mask) {
case V0_VIS:
{
// v0
// / |
// / |
// .....A....B...
// / |
// v3--v2---v1
ClipLine(v3, v0, a);
ClipLine(v0, v1, b);
ViewportVertex3D(v0);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v0, a, b);
}
break;
case V1_VIS:
{
// v1
// / |
// / |
// ....A.....B...
// / |
// v0--v3---v2
ClipLine(v0, v1, a);
ClipLine(v1, v2, b);
ViewportVertex3D(v1);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(a, b, v1);
} break;
case V2_VIS:
{
// v2
// / |
// / |
// ....A.....B...
// / |
// v1--v0---v3
ClipLine(v1, v2, a);
ClipLine(v2, v3, b);
ViewportVertex3D(v2);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(a, b, v2);
} break;
case V3_VIS:
{
// v3
// / |
// / |
// ....A.....B...
// / |
// v2--v1---v0
ClipLine(v2, v3, a);
ClipLine(v3, v0, b);
ViewportVertex3D(v3);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(b, v3, a);
}
break;
case V0_VIS | V1_VIS:
{
// v0-----------v1
// \ |
// ...B.........A...
// \ |
// v3-----v2
ClipLine(v1, v2, a);
ClipLine(v3, v0, b);
ViewportVertex3D(v0);
ViewportVertex3D(v1);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v1, v0, a);
DrawTriangle3D(a, b, v0);
} break;
// case V0_VIS | V2_VIS: degenerate case that should never happen
case V0_VIS | V3_VIS:
{
// v3-----------v0
// \ |
// ...B.........A...
// \ |
// v2-----v1
ClipLine(v0, v1, a);
ClipLine(v2, v3, b);
ViewportVertex3D(v0);
ViewportVertex3D(v3);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(a, v0, b);
DrawTriangle3D(b, v3, v0);
} break;
case V1_VIS | V2_VIS:
{
// v1-----------v2
// \ |
// ...B.........A...
// \ |
// v0-----v3
ClipLine(v2, v3, a);
ClipLine(v0, v1, b);
ViewportVertex3D(v1);
ViewportVertex3D(v2);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v1, b, v2);
DrawTriangle3D(v2, a, b);
} break;
// case V1_VIS | V3_VIS: degenerate case that should never happen
case V2_VIS | V3_VIS:
{
// v2-----------v3
// \ |
// ...B.........A...
// \ |
// v1-----v0
ClipLine(v3, v0, a);
ClipLine(v1, v2, b);
ViewportVertex3D(v2);
ViewportVertex3D(v3);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D( b, a, v2);
DrawTriangle3D(v2, v3, a);
} break;
case V0_VIS | V1_VIS | V2_VIS:
{
// --v1--
// v0-- --v2
// \ /
// ....B.....A...
// \ /
// v3
// v1,v2,v0 v2,v0,A v0,A,B
ClipLine(v2, v3, a);
ClipLine(v3, v0, b);
ViewportVertex3D(v0);
ViewportVertex3D(v1);
ViewportVertex3D(v2);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v1, v0, v2);
DrawTriangle3D(v2, a, v0);
DrawTriangle3D(v0, b, a);
} break;
case V0_VIS | V1_VIS | V3_VIS:
{
// --v0--
// v3-- --v1
// \ /
// ....B.....A...
// \ /
// v2
// v0,v1,v3 v1,v3,A v3,A,B
ClipLine(v1, v2, a);
ClipLine(v2, v3, b);
ViewportVertex3D(v0);
ViewportVertex3D(v1);
ViewportVertex3D(v3);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v0, v3, v1);
DrawTriangle3D(v1, a, v3);
DrawTriangle3D(v3, b, a);
} break;
case V0_VIS | V2_VIS | V3_VIS:
{
// --v3--
// v2-- --v0
// \ /
// ....B.....A...
// \ /
// v1
// v3,v0,v2 v0,v2,A v2,A,B
ClipLine(v0, v1, a);
ClipLine(v1, v2, b);
ViewportVertex3D(v0);
ViewportVertex3D(v2);
ViewportVertex3D(v3);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v3, v2, v0);
DrawTriangle3D(v0, a, v2);
DrawTriangle3D(v2, b, a);
} break;
case V1_VIS | V2_VIS | V3_VIS:
{
// --v2--
// v1-- --v3
// \ /
// ....B.....A...
// \ /
// v0
// v2,v3,v1 v3,v1,A v1,A,B
ClipLine(v3, v0, a);
ClipLine(v0, v1, b);
ViewportVertex3D(v1);
ViewportVertex3D(v2);
ViewportVertex3D(v3);
ViewportVertex3D(a);
ViewportVertex3D(b);
DrawTriangle3D(v2, v1, v3);
DrawTriangle3D(v3, a, v1);
DrawTriangle3D(v1, b, a);
} break;
}
}
void DrawQuads(int startVertex, int verticesCount) {
Vertex vertices[4];
int j = startVertex;
if (gfx_rendering2D) {
// 4 vertices = 1 quad = 2 triangles
for (int i = 0; i < verticesCount / 4; i++, j += 4)
{
TransformVertex2D(j + 0, &vertices[0]);
TransformVertex2D(j + 1, &vertices[1]);
TransformVertex2D(j + 2, &vertices[2]);
TransformVertex2D(j + 3, &vertices[3]);
DrawTriangle2D(&vertices[0], &vertices[2], &vertices[1]);
DrawTriangle2D(&vertices[2], &vertices[0], &vertices[3]);
}
} else {
// 4 vertices = 1 quad = 2 triangles
for (int i = 0; i < verticesCount / 4; i++, j += 4)
{
int clip = TransformVertex3D(j + 0, &vertices[0]) << 0
| TransformVertex3D(j + 1, &vertices[1]) << 1
| TransformVertex3D(j + 2, &vertices[2]) << 2
| TransformVertex3D(j + 3, &vertices[3]) << 3;
if (clip == 0) {
// Quad entirely clipped
} else if (clip == 0x0F) {
// Quad entirely visible
ViewportVertex3D(&vertices[0]);
ViewportVertex3D(&vertices[1]);
ViewportVertex3D(&vertices[2]);
ViewportVertex3D(&vertices[3]);
DrawTriangle3D(&vertices[0], &vertices[2], &vertices[1]);
DrawTriangle3D(&vertices[2], &vertices[0], &vertices[3]);
} else {
// Quad partially visible
DrawClipped(clip, &vertices[0], &vertices[1], &vertices[2], &vertices[3]);
}
}
}
}
void Gfx_SetVertexFormat(VertexFormat fmt) {
gfx_format = fmt;
gfx_stride = strideSizes[fmt];
}
void Gfx_DrawVb_Lines(int verticesCount) { } /* TODO */
void Gfx_DrawVb_IndexedTris_Range(int verticesCount, int startVertex) {
DrawQuads(startVertex, verticesCount);
}
void Gfx_DrawVb_IndexedTris(int verticesCount) {
DrawQuads(0, verticesCount);
}
void Gfx_DrawIndexedTris_T2fC4b(int verticesCount, int startVertex) {
DrawQuads(startVertex, verticesCount);
}
/*########################################################################################################################*
*---------------------------------------------------------Other/Misc------------------------------------------------------*
*#########################################################################################################################*/
static BitmapCol* CB_GetRow(struct Bitmap* bmp, int y, void* ctx) {
return colorBuffer + cb_stride * y;
}
cc_result Gfx_TakeScreenshot(struct Stream* output) {
struct Bitmap bmp;
Bitmap_Init(bmp, fb_width, fb_height, NULL);
return Png_Encode(&bmp, output, CB_GetRow, false, NULL);
}
cc_bool Gfx_WarnIfNecessary(void) { return false; }
cc_bool Gfx_GetUIOptions(struct MenuOptionsScreen* s) { return false; }
void Gfx_BeginFrame(void) { }
void Gfx_EndFrame(void) {
Rect2D r = { 0, 0, fb_width, fb_height };
Window_DrawFramebuffer(r, &fb_bmp);
}
void Gfx_SetVSync(cc_bool vsync) {
gfx_vsync = vsync;
}
void Gfx_OnWindowResize(void) {
if (depthBuffer) DestroyBuffers();
fb_width = Game.Width;
fb_height = Game.Height;
Window_AllocFramebuffer(&fb_bmp, Game.Width, Game.Height);
colorBuffer = fb_bmp.scan0;
cb_stride = fb_bmp.width;
depthBuffer = Mem_Alloc(fb_width * fb_height, 4, "depth buffer");
db_stride = fb_width;
Gfx_SetViewport(0, 0, Game.Width, Game.Height);
Gfx_SetScissor (0, 0, Game.Width, Game.Height);
}
void Gfx_SetViewport(int x, int y, int w, int h) {
vp_hwidth = w / 2.0f;
vp_hheight = h / 2.0f;
}
void Gfx_SetScissor (int x, int y, int w, int h) {
/* TODO minX/Y */
fb_maxX = x + w - 1;
fb_maxY = y + h - 1;
}
void Gfx_GetApiInfo(cc_string* info) {
int pointerSize = sizeof(void*) * 8;
String_Format1(info, "-- Using software (%i bit) --\n", &pointerSize);
PrintMaxTextureInfo(info);
}
cc_bool Gfx_TryRestoreContext(void) { return true; }
#endif