graphics/gpu/loop_subdivision/source/main.c

#include <3ds.h>
#include <citro3d.h>
#include <string.h>
#include "program_shbin.h"
#include "texture_bin.h"
 
#define CLEAR_COLOR 0x68B0D8FF
 
#define DISPLAY_TRANSFER_FLAGS \
    (GX_TRANSFER_FLIP_VERT(0) | GX_TRANSFER_OUT_TILED(0) | GX_TRANSFER_RAW_COPY(0) | \
    GX_TRANSFER_IN_FORMAT(GX_TRANSFER_FMT_RGBA8) | GX_TRANSFER_OUT_FORMAT(GX_TRANSFER_FMT_RGB8) | \
    GX_TRANSFER_SCALING(GX_TRANSFER_SCALE_NO))
 
typedef struct { float position[3]; float texcoord[2]; u8 valence[4]; } vertex;
#define FACE(x,y,z,u,v,_val) \
    { {(x), (y), (z)}, {(u), (v)}, {(_val),0,0,0} }
 
#include "model.obj.h"
#define vertex_list_count (sizeof(vertex_list)/sizeof(vertex_list[0]))
#define index_list_count  (sizeof(index_list) /sizeof(index_list[0]))
 
static DVLB_s* program_dvlb;
static shaderProgram_s program;
static int uLoc_projection, uLoc_modelView;
static int uLoc_passes;
static C3D_Mtx projection;
static C3D_Tex texture;
 
static void* vbo_data;
static void* index_data;
static float angleX = 0.0, angleY = 0.0;
static int sub_level = 1;
 
static void sceneInit(void)
{
    // Load the shaders and create a shader program
    program_dvlb = DVLB_ParseFile((u32*)program_shbin, program_shbin_size);
    shaderProgramInit(&program);
    shaderProgramSetVsh(&program, &program_dvlb->DVLE[0]);
    shaderProgramSetGsh(&program, &program_dvlb->DVLE[1], 0);
    C3D_BindProgram(&program);
 
    // Get the location of the uniforms
    uLoc_projection = shaderInstanceGetUniformLocation(program.vertexShader,   "projection");
    uLoc_modelView  = shaderInstanceGetUniformLocation(program.vertexShader,   "modelView");
    uLoc_passes     = shaderInstanceGetUniformLocation(program.geometryShader, "passes");
 
    // Configure attributes for use with the vertex shader
    C3D_AttrInfo* attrInfo = C3D_GetAttrInfo();
    AttrInfo_Init(attrInfo);
    AttrInfo_AddLoader(attrInfo, 0, GPU_FLOAT,         3); // v0=position
    AttrInfo_AddLoader(attrInfo, 1, GPU_FLOAT,         2); // v1=texcoord
    AttrInfo_AddLoader(attrInfo, 2, GPU_UNSIGNED_BYTE, 4); // v2=valence
 
    // Compute the projection matrix
    Mtx_PerspTilt(&projection, 80.0f*M_PI/180.0f, 400.0f/240.0f, 0.01f, 1000.0f, false);
 
    // Create the VBO (vertex buffer object)
    vbo_data = linearAlloc(sizeof(vertex_list));
    memcpy(vbo_data, vertex_list, sizeof(vertex_list));
    index_data = linearAlloc(sizeof(index_list));
    memcpy(index_data, index_list, sizeof(index_list));
 
    // Configure buffers
    C3D_BufInfo* bufInfo = C3D_GetBufInfo();
    BufInfo_Init(bufInfo);
    BufInfo_Add(bufInfo, vbo_data, sizeof(vertex), 3, 0x210);
 
    // Configure texture
    // Load the texture and bind it to the first texture unit
    C3D_TexInit(&texture, 32, 32, GPU_RGBA8);
    C3D_TexUpload(&texture, texture_bin);
    C3D_TexSetFilter(&texture, GPU_LINEAR, GPU_NEAREST);
    C3D_TexSetWrap(&texture, GPU_REPEAT, GPU_REPEAT);
    C3D_TexBind(0, &texture);
 
    // Configure the first fragment shading substage to just pass through the vertex color
    // See https://www.opengl.org/sdk/docs/man2/xhtml/glTexEnv.xml for more insight
    C3D_TexEnv* env = C3D_GetTexEnv(0);
    C3D_TexEnvInit(env);
    C3D_TexEnvSrc(env, C3D_Both, GPU_TEXTURE0, 0, 0);
    C3D_TexEnvFunc(env, C3D_Both, GPU_REPLACE);
}
 
static void sceneRender(void)
{
    // Calculate the modelView matrix
    C3D_Mtx modelView;
    Mtx_Identity(&modelView);
    Mtx_Translate(&modelView, 0.0, -1.25, -2.5 - angleX, true);
    Mtx_RotateX(&modelView, angleX, true);
    Mtx_RotateY(&modelView, angleY, true);
 
    // Rotate the object each frame
    angleY += M_TAU / 360;
    angleX = (M_TAU / 8) * sinf(angleY);
 
    // Update the uniforms
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_projection, &projection);
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_modelView,  &modelView);
    C3D_FVUnifSet (GPU_GEOMETRY_SHADER, uLoc_passes,     sub_level, 0, 0, 0);
 
    // Draw the VBO
    C3D_DrawElements(GPU_GEOMETRY_PRIM, index_list_count, C3D_UNSIGNED_SHORT, index_data);
}
 
static void sceneExit(void)
{
    // Free the texture
    C3D_TexDelete(&texture);
 
    // Free the VBO
    linearFree(vbo_data);
    linearFree(index_data);
 
    // Free the shader program
    shaderProgramFree(&program);
    DVLB_Free(program_dvlb);
}
 
int main()
{
    // Initialize graphics
    gfxInitDefault();
    C3D_Init(C3D_DEFAULT_CMDBUF_SIZE);
 
    // Initialize the render target
    C3D_RenderTarget* target = C3D_RenderTargetCreate(240, 400, GPU_RB_RGBA8, GPU_RB_DEPTH24_STENCIL8);
    C3D_RenderTargetSetOutput(target, GFX_TOP, GFX_LEFT, DISPLAY_TRANSFER_FLAGS);
 
    // Initialize the scene
    sceneInit();
 
    // Main loop
    while (aptMainLoop())
    {
        hidScanInput();
 
        // Respond to user input
        u32 kDown = hidKeysDown();
        if (kDown & KEY_START)
            break; // break in order to return to hbmenu
 
        if (kDown & KEY_UP)
            sub_level++;
        else if (kDown & KEY_DOWN)
            sub_level--;
        if (sub_level < 0)
            sub_level = 0;
        else if (sub_level > 2)
            sub_level = 2;
 
        // Render the scene
        C3D_FrameBegin(C3D_FRAME_SYNCDRAW);
            C3D_RenderTargetClear(target, C3D_CLEAR_ALL, CLEAR_COLOR, 0);
            C3D_FrameDrawOn(target);
            sceneRender();
        C3D_FrameEnd(0);
    }
 
    // Deinitialize the scene
    sceneExit();
 
    // Deinitialize graphics
    C3D_Fini();
    gfxExit();
    return 0;
}