graphics/gpu/textured_cube/source/main.c

#include <3ds.h>
#include <citro3d.h>
#include <tex3ds.h>
#include <string.h>
#include "vshader_shbin.h"
#include "kitten_t3x.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]; float normal[3]; } vertex;
 
static const vertex vertex_list[] =
{
    // First face (PZ)
    // First triangle
    { {-0.5f, -0.5f, +0.5f}, {0.0f, 0.0f}, {0.0f, 0.0f, +1.0f} },
    { {+0.5f, -0.5f, +0.5f}, {1.0f, 0.0f}, {0.0f, 0.0f, +1.0f} },
    { {+0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, 0.0f, +1.0f} },
    // Second triangle
    { {+0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, 0.0f, +1.0f} },
    { {-0.5f, +0.5f, +0.5f}, {0.0f, 1.0f}, {0.0f, 0.0f, +1.0f} },
    { {-0.5f, -0.5f, +0.5f}, {0.0f, 0.0f}, {0.0f, 0.0f, +1.0f} },
 
    // Second face (MZ)
    // First triangle
    { {-0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {0.0f, 0.0f, -1.0f} },
    { {-0.5f, +0.5f, -0.5f}, {1.0f, 0.0f}, {0.0f, 0.0f, -1.0f} },
    { {+0.5f, +0.5f, -0.5f}, {1.0f, 1.0f}, {0.0f, 0.0f, -1.0f} },
    // Second triangle
    { {+0.5f, +0.5f, -0.5f}, {1.0f, 1.0f}, {0.0f, 0.0f, -1.0f} },
    { {+0.5f, -0.5f, -0.5f}, {0.0f, 1.0f}, {0.0f, 0.0f, -1.0f} },
    { {-0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {0.0f, 0.0f, -1.0f} },
 
    // Third face (PX)
    // First triangle
    { {+0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {+1.0f, 0.0f, 0.0f} },
    { {+0.5f, +0.5f, -0.5f}, {1.0f, 0.0f}, {+1.0f, 0.0f, 0.0f} },
    { {+0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {+1.0f, 0.0f, 0.0f} },
    // Second triangle
    { {+0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {+1.0f, 0.0f, 0.0f} },
    { {+0.5f, -0.5f, +0.5f}, {0.0f, 1.0f}, {+1.0f, 0.0f, 0.0f} },
    { {+0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {+1.0f, 0.0f, 0.0f} },
 
    // Fourth face (MX)
    // First triangle
    { {-0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {-1.0f, 0.0f, 0.0f} },
    { {-0.5f, -0.5f, +0.5f}, {1.0f, 0.0f}, {-1.0f, 0.0f, 0.0f} },
    { {-0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {-1.0f, 0.0f, 0.0f} },
    // Second triangle
    { {-0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {-1.0f, 0.0f, 0.0f} },
    { {-0.5f, +0.5f, -0.5f}, {0.0f, 1.0f}, {-1.0f, 0.0f, 0.0f} },
    { {-0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {-1.0f, 0.0f, 0.0f} },
 
    // Fifth face (PY)
    // First triangle
    { {-0.5f, +0.5f, -0.5f}, {0.0f, 0.0f}, {0.0f, +1.0f, 0.0f} },
    { {-0.5f, +0.5f, +0.5f}, {1.0f, 0.0f}, {0.0f, +1.0f, 0.0f} },
    { {+0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, +1.0f, 0.0f} },
    // Second triangle
    { {+0.5f, +0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, +1.0f, 0.0f} },
    { {+0.5f, +0.5f, -0.5f}, {0.0f, 1.0f}, {0.0f, +1.0f, 0.0f} },
    { {-0.5f, +0.5f, -0.5f}, {0.0f, 0.0f}, {0.0f, +1.0f, 0.0f} },
 
    // Sixth face (MY)
    // First triangle
    { {-0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {0.0f, -1.0f, 0.0f} },
    { {+0.5f, -0.5f, -0.5f}, {1.0f, 0.0f}, {0.0f, -1.0f, 0.0f} },
    { {+0.5f, -0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, -1.0f, 0.0f} },
    // Second triangle
    { {+0.5f, -0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, -1.0f, 0.0f} },
    { {-0.5f, -0.5f, +0.5f}, {0.0f, 1.0f}, {0.0f, -1.0f, 0.0f} },
    { {-0.5f, -0.5f, -0.5f}, {0.0f, 0.0f}, {0.0f, -1.0f, 0.0f} },
};
 
#define vertex_list_count (sizeof(vertex_list)/sizeof(vertex_list[0]))
 
static DVLB_s* vshader_dvlb;
static shaderProgram_s program;
static int uLoc_projection, uLoc_modelView;
static int uLoc_lightVec, uLoc_lightHalfVec, uLoc_lightClr, uLoc_material;
static C3D_Mtx projection;
static C3D_Mtx material =
{
    {
    { { 0.0f, 0.2f, 0.2f, 0.2f } }, // Ambient
    { { 0.0f, 0.4f, 0.4f, 0.4f } }, // Diffuse
    { { 0.0f, 0.8f, 0.8f, 0.8f } }, // Specular
    { { 1.0f, 0.0f, 0.0f, 0.0f } }, // Emission
    }
};
 
static void* vbo_data;
static C3D_Tex kitten_tex;
static float angleX = 0.0, angleY = 0.0;
 
// Helper function for loading a texture from memory
static bool loadTextureFromMem(C3D_Tex* tex, C3D_TexCube* cube, const void* data, size_t size)
{
    Tex3DS_Texture t3x = Tex3DS_TextureImport(data, size, tex, cube, false);
    if (!t3x)
        return false;
 
    // Delete the t3x object since we don't need it
    Tex3DS_TextureFree(t3x);
    return true;
}
 
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");
    uLoc_lightVec     = shaderInstanceGetUniformLocation(program.vertexShader, "lightVec");
    uLoc_lightHalfVec = shaderInstanceGetUniformLocation(program.vertexShader, "lightHalfVec");
    uLoc_lightClr     = shaderInstanceGetUniformLocation(program.vertexShader, "lightClr");
    uLoc_material     = shaderInstanceGetUniformLocation(program.vertexShader, "material");
 
    // 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_FLOAT, 3); // v2=normal
 
    // Compute the projection matrix
    Mtx_PerspTilt(&projection, C3D_AngleFromDegrees(80.0f), C3D_AspectRatioTop, 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));
 
    // Configure buffers
    C3D_BufInfo* bufInfo = C3D_GetBufInfo();
    BufInfo_Init(bufInfo);
    BufInfo_Add(bufInfo, vbo_data, sizeof(vertex), 3, 0x210);
 
    // Load the texture and bind it to the first texture unit
    if (!loadTextureFromMem(&kitten_tex, NULL, kitten_t3x, kitten_t3x_size))
        svcBreak(USERBREAK_PANIC);
    C3D_TexSetFilter(&kitten_tex, GPU_LINEAR, GPU_NEAREST);
    C3D_TexBind(0, &kitten_tex);
 
    // Configure the first fragment shading substage to blend the texture color with
    // the vertex color (calculated by the vertex shader using a lighting algorithm)
    // 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, GPU_PRIMARY_COLOR, 0);
    C3D_TexEnvFunc(env, C3D_Both, GPU_MODULATE);
}
 
static void sceneRender(void)
{
    // Calculate the modelView matrix
    C3D_Mtx modelView;
    Mtx_Identity(&modelView);
    Mtx_Translate(&modelView, 0.0, 0.0, -2.0 + 0.5*sinf(angleX), true);
    Mtx_RotateX(&modelView, angleX, true);
    Mtx_RotateY(&modelView, angleY, true);
 
    // Rotate the cube each frame
    angleX += M_PI / 180;
    angleY += M_PI / 360;
 
    // Update the uniforms
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_projection, &projection);
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_modelView,  &modelView);
    C3D_FVUnifMtx4x4(GPU_VERTEX_SHADER, uLoc_material,   &material);
    C3D_FVUnifSet(GPU_VERTEX_SHADER, uLoc_lightVec,     0.0f, 0.0f, -1.0f, 0.0f);
    C3D_FVUnifSet(GPU_VERTEX_SHADER, uLoc_lightHalfVec, 0.0f, 0.0f, -1.0f, 0.0f);
    C3D_FVUnifSet(GPU_VERTEX_SHADER, uLoc_lightClr,     1.0f, 1.0f,  1.0f, 1.0f);
 
    // Draw the VBO
    C3D_DrawArrays(GPU_TRIANGLES, 0, vertex_list_count);
}
 
static void sceneExit(void)
{
    // Free the texture
    C3D_TexDelete(&kitten_tex);
 
    // Free the VBO
    linearFree(vbo_data);
 
    // Free the shader program
    shaderProgramFree(&program);
    DVLB_Free(vshader_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
 
        // 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;
}