gistfile1.txt

#define MG_PLATFORM_IMPLEMENTATION
#define MG_TOOL_IMPLEMENTATION
#define MGGL_IMPLEMENTATION
#define MG_PLATFORM_OPENGL
#define MG_PLATFORM_OPENGL_DEBUG
#define MGGL_DEBUG
#define MG_PLATFORM_LOOP		gameLoop
#define MG_PLATFORM_INIT		initGame
#define MG_PLATFORM_CONFIG		configGame

#include "mg_tool.h"
#include "mg_platform.h"
#include "mg_gl.h"
#pragma comment(lib, "OpenGL32.lib")

mgPlatform *gp;

void configGame(mgPlatformConfig *cfg, const mgPlatformInfo *info) {
	cfg->window_width = 1600;
	cfg->window_height = 900;
}

int initGame(struct mgPlatform *platform, const char *argv) {
	gp = platform;
	mggl_bsInit(platform->window_width, platform->window_height);
	return 0;
}

mgVec2 bezier_pts[4];
int editing_pt_id;
int editing_line_pt_id;


r32 length[2] = { 100.f, 100.f };
r32 length_dist_fact = 0.5f;

struct Line {
	mgVec2 pts[2];
};

Line lines[2] = {
	{ 100.f, 100.f, 300.f, 250.f },
	{ 1000.f, 100.f, 800.f, 450.f },
};

int gameLoop(r32 dt) {
	{ //input
		mg_fei(bezier_pts) {
			if (gp->input_state.key_state[mgKey_1 + i] & mgButtonState_Press) {
				editing_pt_id = i;
				editing_line_pt_id = -1;
			}
		}
		if (gp->input_state.key_state['A'] & mgButtonState_Press) {
			editing_pt_id = -1;
			editing_line_pt_id = 0;
		}
		if (gp->input_state.key_state['S'] & mgButtonState_Press) {
			editing_pt_id = -1;
			editing_line_pt_id = 1;
		}
		if (gp->input_state.key_state['D'] & mgButtonState_Press) {
			editing_pt_id = -1;
			editing_line_pt_id = 2;
		}
		if (gp->input_state.key_state['F'] & mgButtonState_Press) {
			editing_pt_id = -1;
			editing_line_pt_id = 3;
		}
		if (editing_pt_id >= 0 && editing_pt_id < MG_ARR_LEN(bezier_pts)) {
			if (gp->input_state.mouse_buttons[0] & mgButtonState_Down) {
				bezier_pts[editing_pt_id] = gp->input_state.mouse_pos;
			}
		} else if (editing_line_pt_id != -1) {
			mgVec2 *line_pts = (mgVec2 *)lines;
			if (gp->input_state.mouse_buttons[0] & mgButtonState_Down) {
				line_pts[editing_line_pt_id] = gp->input_state.mouse_pos;
			}
		}
		//int len_id = (gp->input_state.key_state[mgKey_ShiftLeft] & mgButtonState_Down) ? 1 : 0;
		//length[len_id] += (r32)gp->input_state.mouse_wheel * 10.f;
		length_dist_fact += (r32)gp->input_state.mouse_wheel * 0.025f;
	}

	r32 len_between_end_points  = mg_vec2Len(lines[0].pts[1] - lines[1].pts[1]);
	

	mgVec2 v0 = mg_vec2GetUnit(lines[0].pts[0] - lines[0].pts[1]);
	mgVec2 v1 = mg_vec2GetUnit(lines[1].pts[0] - lines[1].pts[1]);

	r32 dp = mg_vec2Dot(v0, v1);

	len_between_end_points /= mg_smootherStep(0.f, 1.f, mg_abs32(dp));

	bezier_pts[0] = lines[0].pts[1];
//	bezier_pts[1] = lines[0].pts[1] - v0 * length[0];
//	bezier_pts[2] = lines[1].pts[1] - v1 * length[1];
	bezier_pts[1] = lines[0].pts[1] - v0 * len_between_end_points * length_dist_fact;
	bezier_pts[2] = lines[1].pts[1] - v1 * len_between_end_points * length_dist_fact;
	bezier_pts[3] = lines[1].pts[1];
	


	mggl_bsSetRes(gp->window_width, gp->window_height);
	mggl_bsSetFSViewport();
	mggl_clearScreen(mg_col_black);

	glUseProgram(mggl_state->ortho_col_shader.program);
	glUniformMatrix4fv(mggl_state->ortho_col_shader.getUniform("ortho_mat"), 1, GL_FALSE, mggl_state->ortho_mat);
	mggl_uniformFloatColour(mggl_state->ortho_col_shader.getUniform("in_colour"), mg_col_white);

	
	{ //draw curve
		int num_subdivisions = 512;
		glBegin(GL_LINE_STRIP);
		mg_fiz(num_subdivisions) {
			r32 t = (r32)i / (r32)(num_subdivisions - 1);
			mgVec2 p = mg_bezierCubic2Df(t, bezier_pts);
			glVertex2fv((r32 *)&p);
		}
		glEnd();
	}
	{ //draw tangent handles
		mggl_uniformFloatColour(mggl_state->ortho_col_shader.getUniform("in_colour"), mg_col_yellow);
		glBegin(GL_LINES);
		mg_fei(bezier_pts) {
			glVertex2fv((r32 *)(bezier_pts + i));
		}
		glEnd();
	}
	{ //draw lines
		mggl_uniformFloatColour(mggl_state->ortho_col_shader.getUniform("in_colour"), mg_col_red);
		glBegin(GL_LINES);
		mgVec2 *line_pts = (mgVec2 *)lines;
		mg_fiz(4) {
			glVertex2fv((r32 *)(line_pts + i));
		}
		glEnd();
	}

	{ //ui
		int font_size = 24;
		int font_spacing = (int)((r32)font_size * 1.25f);
		mgglFont *font = mggl_getFont("Arial", font_size);
		int top = gp->window_height - font_spacing;
		int x = 10;
		int y = top;

		mggl_drawString(font, x, y, mg_col_white, "Editing curve point: %d", editing_pt_id);					y -= font_spacing;
		mggl_drawString(font, x, y, mg_col_white, "Editing line point:  %d", editing_line_pt_id);				y -= font_spacing;
		mggl_drawString(font, x, y, mg_col_white, "dot product: %f", dp);										y -= font_spacing;
		mggl_drawString(font, x, y, mg_col_white, "smooth dot product: %f", mg_smootherStep(0.f, 1.f, dp));		y -= font_spacing;
		/*mg_fei(bezier_pts) {
			mggl_drawString(font, bezier_pts[i].x, bezier_pts[i].y, mg_col_white, "%d (%3.2f, %3.2f)", i + 1, bezier_pts[i].x, bezier_pts[i].y);
		}*/

		const char *fuck = "ASDF";
		mgVec2 *line_pts = (mgVec2 *)lines;
		mg_fei(fuck) {
			mggl_drawString(font, line_pts[i].x, line_pts[i].y, mg_col_white, "%c (%3.2f, %3.2f)", fuck[i], line_pts[i].x, line_pts[i].y);
		}
	}

	return 0;
}