mipmap test

main.c

#include <3ds.h>
#include <citro3d.h>
#include <tex3ds.h>
#include <string.h>
#include <stdlib.h>
#include "vshader_shbin.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
	{ {-1.0f, -0.5f, -6.0f}, {0.0f, 0.0f}, {0.0f, 0.0f, +1.0f} },
	{ {+1.0f, -0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, 0.0f, +1.0f} },
	{ {+1.0f, -0.5f, -6.0f}, {1.0f, 0.0f}, {0.0f, 0.0f, +1.0f} },
	// Second triangle
	{ {+1.0f, -0.5f, +0.5f}, {1.0f, 1.0f}, {0.0f, 0.0f, +1.0f} },
	{ {-1.0f, -0.5f, -6.0f}, {0.0f, 0.0f}, {0.0f, 0.0f, +1.0f} },
	{ {-1.0f, -0.5f, +0.5f}, {0.0f, 1.0f}, {0.0f, 0.0f, +1.0f} },

};

#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 logo_tex;

u8 max_level = 7;
u16 width = 1024, height = 1024;

float bias = 0.0f;
bool linear = false;

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, 20.0f, 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
	C3D_TexInitWithParams(&logo_tex, 0,
		(C3D_TexInitParams){ width, height, max_level, GPU_RGBA8, GPU_TEX_2D, false });

	u16 w = width, h = height;
	u32 level_color[8] = {
		0xFF0000FF,
		0x00FF00FF,
		0x0000FFFF,
		0xFFFF00FF,
		0x00FFFFFF,
		0xFF00FFFF,
		0xFFFFFFFF,
		0x000000FF,
	};
	for (u8 level = 0; level <= max_level; ++level) {
		u32* colors = malloc(4 * w * h);

		for (u32 i = 0; i < w * h; ++i) {
			colors[i] = level_color[level];
		}
		C3D_TexLoadImage(&logo_tex, colors, 0, level);
		free(colors);
		w /= 2;
		h /= 2;
	}

	C3D_TexSetFilter(&logo_tex, GPU_LINEAR, GPU_NEAREST);
	C3D_TexSetFilterMipmap(&logo_tex, GPU_NEAREST);
	C3D_TexBind(0, &logo_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, -1.1, true);

	// 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);


	C3D_TexSetFilterMipmap(&logo_tex, linear ? GPU_LINEAR : GPU_NEAREST);
	C3D_TexSetLodBias(&logo_tex, bias);
	C3D_TexBind(0, &logo_tex);

	// Draw the VBO
	C3D_DrawArrays(GPU_TRIANGLES, 0, vertex_list_count);
}

static void sceneExit(void)
{
	// Free the texture
	C3D_TexDelete(&logo_tex);

	// Free the VBO
	linearFree(vbo_data);

	// Free the shader program
	shaderProgramFree(&program);
	DVLB_Free(vshader_dvlb);
}

int main()
{
	// Initialize graphics
	gfxInitDefault();
	consoleInit(GFX_BOTTOM, NULL);
	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_A) {
			linear = !linear;
		}

		if (kDown & KEY_B) {
			bias = 0;
		}

		if (kDown & KEY_X) {
			bias += 0.2f;
		}

		if (kDown & KEY_Y) {
			bias -= 0.2f;
		}

		// 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;
}

vshader.v.pica

; Example PICA200 vertex shader

; Uniforms
.fvec projection[4], modelView[4]
.fvec lightVec, lightHalfVec, lightClr, material[4]
.alias mat_amb material[0]
.alias mat_dif material[1]
.alias mat_spe material[2]
.alias mat_emi material[3]

; Constants
.constf myconst(0.0, 1.0, -1.0, -0.5)
.alias  zeros myconst.xxxx ; Vector full of zeros
.alias  ones  myconst.yyyy ; Vector full of ones

; Outputs
.out outpos position
.out outtc0 texcoord0
.out outclr color

; Inputs (defined as aliases for convenience)
.alias inpos v0
.alias intex v1
.alias innrm v2

.proc main
	; Force the w component of inpos to be 1.0
	mov r0.xyz, inpos
	mov r0.w,   ones

	; r1 = modelView * inpos
	dp4 r1.x, modelView[0], r0
	dp4 r1.y, modelView[1], r0
	dp4 r1.z, modelView[2], r0
	dp4 r1.w, modelView[3], r0

	; outpos = projection * r1
	dp4 outpos.x, projection[0], r1
	dp4 outpos.y, projection[1], r1
	dp4 outpos.z, projection[2], r1
	dp4 outpos.w, projection[3], r1

	; outtex = intex
	mov outtc0, intex

	; Transform the normal vector with the modelView matrix
	; r1 = normalize(modelView * innrm)
	mov r0.xyz, innrm
	mov r0.w,   zeros
	dp4 r1.x,   modelView[0], r0
	dp4 r1.y,   modelView[1], r0
	dp4 r1.z,   modelView[2], r0
	mov r1.w,   zeros
	dp3 r2,     r1, r1 ; r2 = x^2+y^2+z^2 for each component
	rsq r2,     r2     ; r2 = 1/sqrt(r2)  ''
	mul r1,     r2, r1 ; r1 = r1*r2

	; Calculate the diffuse level (r0.x) and the shininess level (r0.y)
	; r0.x = max(0, -(lightVec * r1))
	; r0.y = max(0, (-lightHalfVec[i]) * r1) ^ 2
	dp3 r0.x, lightVec,      r1
	add r0.x, zeros,         -r0
	dp3 r0.y, -lightHalfVec, r1
	max r0,   zeros,         r0
	mul r0.y, r0,            r0

	; Accumulate the vertex color in r1, initializing it to the emission color
	mov r1, mat_emi

	; r1 += specularColor * lightClr * shininessLevel
	mul r2, lightClr, r0.yyyy
	mad r1, r2, mat_spe, r1

	; r1 += diffuseColor * lightClr * diffuseLevel
	mul r2, lightClr, r0.xxxx
	mad r1, r2, mat_dif, r1

	; r1 += ambientColor * lightClr
	mov r2, lightClr
	mad r1, r2, mat_amb, r1

	; outclr = clamp r1 to [0,1]
	min outclr, ones, r1

	; We're finished
	end
.end