graphics/gpu/toon_shading/source/main.c

#include <3ds.h>
#include <citro3d.h>
#include <string.h>
#include "vshader_shbin.h"
#include "teapot.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))
 
static DVLB_s* vshader_dvlb;
static shaderProgram_s program;
static int uLoc_projection, uLoc_modelView;
static C3D_Mtx projection;
 
static C3D_LightEnv lightEnv;
static C3D_Light light;
static C3D_LightLut lut_Spec, lut_Toon;
 
static void* vbo_data;
#ifdef vertex_element_count
static void* ibo_data;
#endif
static float angleX = 0.0, angleY = 0.0;
 
#define NUM_DIFFUSE_TONES 3
static float toon_diffuse(float x, float arg)
{
    const float factor = NUM_DIFFUSE_TONES-1;
    return floorf(0.5f+x*factor)/factor;
}
 
#define NUM_SPECULAR_TONES 2
static float toon_specular(float x, float shininess)
{
    const float factor = NUM_SPECULAR_TONES-1;
    return floorf(0.5f+powf(x, shininess)*factor)/factor;
}
 
static void sceneInit(void)
{
    // Load the vertex shader, create a shader program and bind it
    vshader_dvlb = DVLB_ParseFile((u32*)vshader_shbin, vshader_shbin_size);
    shaderProgramInit(&program);
    shaderProgramSetVsh(&program, &vshader_dvlb->DVLE[0]);
    C3D_BindProgram(&program);
 
    // Get the location of the uniforms
    uLoc_projection   = shaderInstanceGetUniformLocation(program.vertexShader, "projection");
    uLoc_modelView    = shaderInstanceGetUniformLocation(program.vertexShader, "modelView");
 
    // 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, 3); // v1=normal
 
    // Create the VBO (vertex buffer object)
    vbo_data = linearAlloc(sizeof(vertex_array));
    memcpy(vbo_data, vertex_array, sizeof(vertex_array));
#ifdef vertex_element_count
    ibo_data = linearAlloc(sizeof(vertex_elements));
    memcpy(ibo_data, vertex_elements, sizeof(vertex_elements));
#endif
 
    // Configure buffers
    C3D_BufInfo* bufInfo = C3D_GetBufInfo();
    BufInfo_Init(bufInfo);
    BufInfo_Add(bufInfo, vbo_data, sizeof(float[6]), 2, 0x10);
 
    // Configure the first fragment shading substage to blend the fragment primary color
    // with the fragment secondary 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_RGB, GPU_FRAGMENT_PRIMARY_COLOR, GPU_FRAGMENT_SECONDARY_COLOR, 0);
    C3D_TexEnvSrc(env, C3D_Alpha, GPU_PRIMARY_COLOR, 0, 0);
    C3D_TexEnvFunc(env, C3D_RGB, GPU_ADD);
    C3D_TexEnvFunc(env, C3D_Alpha, GPU_REPLACE);
 
    static const C3D_Material material =
    {
        { 0.2f, 0.2f, 0.2f }, //ambient
        { 0.0f, 0.0f, 0.0f }, //diffuse
        { 0.4f, 0.4f, 0.4f }, //specular0
        { 0.4f, 0.4f, 0.4f }, //specular1
        { 0.0f, 0.0f, 0.0f }, //emission
    };
 
    C3D_LightEnvInit(&lightEnv);
    C3D_LightEnvBind(&lightEnv);
    C3D_LightEnvMaterial(&lightEnv, &material);
 
    LightLut_FromFunc(&lut_Toon, toon_diffuse, 0.0f, false);
    LightLut_FromFunc(&lut_Spec, toon_specular, 30.0f, false);
    C3D_LightEnvLut(&lightEnv, GPU_LUT_D0, GPU_LUTINPUT_NH, false, &lut_Spec);
    C3D_LightEnvLut(&lightEnv, GPU_LUT_D1, GPU_LUTINPUT_LN, false, &lut_Toon);
 
    C3D_LightInit(&light, &lightEnv);
}
 
static void sceneRender(float iod)
{
    // Compute the projection matrix
    Mtx_PerspStereoTilt(&projection, C3D_AngleFromDegrees(40.0f), C3D_AspectRatioTop, 0.01f, 1000.0f, iod, 3.0f, false);
 
    C3D_FVec objPos   = FVec4_New(0.0f, 0.0f, -3.0f, 1.0f);
    C3D_FVec lightPos = FVec4_New(0.0f, 0.0f, -0.5f, 1.0f);
 
    // Calculate the modelView matrix
    C3D_Mtx modelView;
    Mtx_Identity(&modelView);
    Mtx_Translate(&modelView, objPos.x, objPos.y, objPos.z, true);
    Mtx_RotateX(&modelView, C3D_Angle(sinf(angleX)/4), true);
    Mtx_RotateY(&modelView, C3D_Angle(angleY), true);
    Mtx_Translate(&modelView, 0.0f, -0.5f, 0.f, true);
 
    C3D_LightPosition(&light, &lightPos);
 
    // Update the uniforms
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_projection, &projection);
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_modelView,  &modelView);
 
    // Draw the VBO
#ifdef vertex_element_count
    C3D_DrawElements(GPU_TRIANGLES, vertex_element_count, C3D_UNSIGNED_SHORT, ibo_data);
#else
    C3D_DrawArrays(GPU_TRIANGLES, 0, vertex_array_count);
#endif
}
 
static void sceneExit(void)
{
    // Free the VBO
    linearFree(vbo_data);
#ifdef vertex_element_count
    linearFree(ibo_data);
#endif
 
    // Free the shader program
    shaderProgramFree(&program);
    DVLB_Free(vshader_dvlb);
}
 
int main()
{
    // Initialize graphics
    gfxInitDefault();
    gfxSet3D(true); // Enable stereoscopic 3D
    consoleInit(GFX_BOTTOM, NULL);
    C3D_Init(C3D_DEFAULT_CMDBUF_SIZE);
 
    // Initialize the render targets
    C3D_RenderTarget* targetLeft  = C3D_RenderTargetCreate(240, 400, GPU_RB_RGBA8, GPU_RB_DEPTH24_STENCIL8);
    C3D_RenderTarget* targetRight = C3D_RenderTargetCreate(240, 400, GPU_RB_RGBA8, GPU_RB_DEPTH24_STENCIL8);
    C3D_RenderTargetSetOutput(targetLeft,  GFX_TOP, GFX_LEFT,  DISPLAY_TRANSFER_FLAGS);
    C3D_RenderTargetSetOutput(targetRight, GFX_TOP, GFX_RIGHT, DISPLAY_TRANSFER_FLAGS);
 
    // Initialize the scene
    sceneInit();
 
    // Main loop
    while (aptMainLoop())
    {
        hidScanInput();
 
        // Respond to user input
        u32 kDown = hidKeysDown();
        u32 kHeld = hidKeysHeld();
        if (kDown & KEY_START)
            break; // break in order to return to hbmenu
 
        float slider = osGet3DSliderState();
        float iod = slider/2;
 
        // Rotate the model
        if (!(kHeld & KEY_A))
        {
            angleX += 1.0f/64;
            angleY += 1.0f/256;
        }
 
        // Render the scene
        C3D_FrameBegin(C3D_FRAME_SYNCDRAW);
        {
            C3D_RenderTargetClear(targetLeft, C3D_CLEAR_ALL, CLEAR_COLOR, 0);
            C3D_FrameDrawOn(targetLeft);
            sceneRender(-iod);
 
            if (iod > 0.0f)
            {
                C3D_RenderTargetClear(targetRight, C3D_CLEAR_ALL, CLEAR_COLOR, 0);
                C3D_FrameDrawOn(targetRight);
                sceneRender(iod);
            }
        }
        C3D_FrameEnd(0);
    }
 
    // Deinitialize the scene
    sceneExit();
 
    // Deinitialize graphics
    C3D_Fini();
    gfxExit();
    return 0;
}